JDK 26 Documentation

https://docs.oracle.com/en/java/javase/26/
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### Create and Start a Simple Process

Source: https://docs.oracle.com/en/java/javase/26/core/creating-process.html

Use ProcessBuilder to specify the command and arguments, then start the process. This is a basic example for executing a command.

```Java
ProcessBuilder pb = new ProcessBuilder("echo", "Hello World!");
Process p = pb.start();
```

--------------------------------

### Recording Configuration, Start, Stop, and Dump Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/jdk.jfr/jdk/jfr/Recording.html

This example demonstrates how to use the Recording class to configure, start, stop, and dump recording data to a file. It utilizes a try-with-resources statement for automatic closing of the recording.

```APIDOC
## Recording Configuration, Start, Stop, and Dump Example

### Description
This example shows how to configure, start, stop, and dump recording data to disk using the `Recording` class. It utilizes a `try-with-resources` statement to ensure the recording is properly closed.

### Usage
```java
Configuration c = Configuration.getConfiguration("default");
try (Recording r = new Recording(c)) {
    r.start();
    System.gc(); // Example of an action to record
    Thread.sleep(5000); // Wait for 5 seconds to collect data
    r.stop();
    r.dump(Files.createTempFile("my-recording", ".jfr")); // Dump recording to a temporary file
}
```

### Methods Used
- `Configuration.getConfiguration(String name)`: Retrieves a predefined recording configuration.
- `Recording(Configuration)`: Constructs a new `Recording` instance with the specified configuration.
- `start()`: Starts the recording.
- `stop()`: Stops the recording.
- `dump(Path path)`: Dumps the recording data to the specified file path.
- `close()`: Closes the recording (automatically called when using try-with-resources).
```

--------------------------------

### Example: Starting AOT Recording with JVM Options

Source: https://docs.oracle.com/en/java/javase/26/docs/api/jdk.management/jdk/management/HotSpotAOTCacheMXBean.html

This example demonstrates how to start AOT recording using JVM command-line options. The JVM records optimization information for the current application in the AOT cache file. This cache can then be used in a future run to improve startup and warmup performance.

```bash
java -XX:AOTCacheOutput=app.aot ....
```

--------------------------------

### SLP Lookup Service Example README

Source: https://docs.oracle.com/en/java/javase/26/jmx/service-location-protocol-slp-lookup-service-example.html

This README file provides setup instructions and commands for compiling and running the SLP lookup service example. It details requirements, environment variables, and necessary daemon startups.

```shell
#
# Copyright (c) 2004, 2019 Oracle and/or its affiliates. All rights reserved.
# ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
#

# ==============================================================================
#
# Example of using SLP as Lookup service - registering and looking up
# an RMI Connector (IIOP/JRMP)
#
# ==============================================================================
#
# Requirements:
#
# The code provided in this example is build against the Java
# implementation of SLP - compliant with RFC 2614 see
# [http://www.ietf.org/rfc/rfc2614.txt].
#
#
# Before running this example you will have to:
#     get a Java implementation of SLP compliant with
#     RFC 2614, section 5. You can download the OpenSLP Java implementation
#     from http://www.openslp.org/. Then you may have to modify Client.java
#     and Server.java in order to use <my-slp-impl>.slp instead of
#     com.sun.slp. If your SLP implementation is RFC 2614 compliant
#     the changes should be limited to replacing 'com.sun.slp' in the
#     import clauses by '<my-slp-impl>.slp'.
#
# If you wish to use an external directory for the RMI JMX Connectors
# (URLs of the form jmx:service:[rmi|iiop]:/host:port/jndi/jndi-url)
# then:
#
#   o If you wish to use rmiregistry in conjunction with the RMI/JRMP
#     JMX Connector you will have to start a rmiregistry (see below).
#
#   o If you wish to use CORBA Naming Service in conjunction with the RMI/IIOP
#     JMX Connector you will have to start an ORB daemon (see below).
#
#   o If you wish to use LDAP in conjunction with the RMI JMX Connectors
#     you will have to install/setup a directory server
#
# In order to compile and run the example, make a copy of this README file, and
# then simply cut and paste all the commands as needed into a terminal window.
#
# This README makes the assumption that you are running under Java SE 6 on Unix,
# you are familiar with SLP, the JMX technology, with LDAP and JNDI, and with
# the bourne shell or korn shell syntax.
#
# All the commands below are defined using Unix korn shell syntax.
#
# If you are not running Unix and korn shell you are expected to be able to
# adapt these commands to your favorite OS and shell environment.
#

# Define the following variables:
#
SLPLIB=$SLP_HOME

classp=$SLPLIB/slp.jar

#-------------------------------------------------------------------------------
# The SLP daemon needs to be launched with root privilege on each
# host who uses the SLP API. To launch the SLP daemon, simply type
# the following command line:
#
su root -c "java -cp $SLPLIB/slpd.jar com.sun.slp.slpd &"

#-------------------------------------------------------------------------------
# Start an rmiregistry
#
rmiregistry 9999 &

#-------------------------------------------------------------------------------
# Start an ORB daemon:
#
rm -rf ./orb.db
orbd -ORBInitialPort 7777 &

#-------------------------------------------------------------------------------
# Start an LDAP Server, and create a new dc=Test suffix inside.
#
# (only needed if you wish to register the RMI or IIOP stubs in
# LDAP, instead of using CORBA Naming Service or RMI registry)
#
#       You will have
#       to make sure the Java Schema (RFC 2713:
#       http://www.ietf.org/rfc/rfc2713.txt) is known by that server

#-------------------------------------------------------------------------------
# Compile Server.java and Client.java
#
# * Server.java: creates an MBeanServer, creates and starts an
#                RMI connector (JRMP/IIOP)
# * Client.java: lookup a connector in SLP
#                list all MBeans.
#
javac -d . -classpath $classp Server.java Client.java

```

--------------------------------

### Start Main Application for JMX Example

Source: https://docs.oracle.com/en/java/javase/26/jmx/essentials-jmx-api.html

Run the main application that sets up and registers the MBean.

```bash
java com.example.mbeans.Main
```

--------------------------------

### Minimal HTTP Server Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/jdk.httpserver/com/sun/net/httpserver/package-summary.html

This example demonstrates how to create a basic HTTP server that listens on a specified port and handles requests for a particular path. It shows the implementation of a custom HttpHandler and the server setup process.

```APIDOC
## Minimal HTTP Server Example

### Description
This example demonstrates how to create a basic HTTP server that listens on a specified port and handles requests for a particular path. It shows the implementation of a custom HttpHandler and the server setup process.

### Code
```java
class MyHandler implements HttpHandler {
    public void handle(HttpExchange t) throws IOException {
        InputStream is = t.getRequestBody();
        read(is); // .. read the request body
        String response = "This is the response";
        t.sendResponseHeaders(200, response.length());
        OutputStream os = t.getResponseBody();
        os.write(response.getBytes());
        os.close();
    }
}

HttpServer server = HttpServer.create(new InetSocketAddress(8000), 0);
server.createContext("/applications/myapp", new MyHandler());
server.setExecutor(null); // creates a default executor
server.start();
```
```

--------------------------------

### installUI Method

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/plaf/basic/BasicEditorPaneUI.html

Installs the UI for a component, performing several setup tasks.

```APIDOC
## installUI(JComponent c)

### Description
Installs the UI for a component. This does the following things:
1. Sets the associated component to opaque if the opaque property has not already been set by the client program. This will cause the component's background color to be painted.
2. Installs the default caret and highlighter into the associated component. These properties are only set if their current value is either `null` or an instance of `UIResource`.
3. Attaches to the editor and model. If there is no model, a default one is created.
4. Creates the view factory and the view hierarchy used to represent the model.

### Method
`public void installUI(JComponent c)`

### Parameters
* **c** (JComponent) - the editor component

### Overrides
`installUI` in class `BasicTextUI`

### Since
1.5

### See Also
* `ComponentUI.installUI(JComponent)`
```

--------------------------------

### Capturing Process Output Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/Process.html

Example demonstrating how to start a process, capture its standard output, wait for it to complete, and check its exit status using try-with-resources for stream management.

```APIDOC
## Example: Capturing Process Output

### Description
This example shows how to execute a command, capture its standard output into a list of strings, wait for the process to finish, and handle potential errors based on the exit status.

### Code
```java
List<String> capture(List<String> args) throws Exception {
    ProcessBuilder pb = new ProcessBuilder(args);
    try (Process process = pb.start();
         BufferedReader in = process.inputReader()) {
        List<String> captured = in.readAllLines();
        int status = process.waitFor();
        if (status != 0) {
            throw new RuntimeException("Process %d: %s failed with %d"
                        .formatted(process.pid(), args, status));
        }
        return captured;
    }
}
```

### Parameters
- `args` (List<String>) - The command and its arguments to execute.
```

--------------------------------

### JVM Startup Command Example

Source: https://docs.oracle.com/en/java/javase/26/docs/specs/jls/jls-12.html

This command line demonstrates how to start a Java Virtual Machine and pass arguments to the main method of a specified class. The first argument is the class name, and subsequent arguments are passed as strings to the main method's String array parameter.

```bash
java Test reboot Bob Dot Enzo

```

--------------------------------

### Timer Constructor and Start Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/Timer.html

This example demonstrates how to create and start a javax.swing.Timer that fires an ActionEvent once per second. It shows the basic setup of specifying a delay and an ActionListener.

```APIDOC
## Timer Constructor and Start Example

### Description
This code snippet illustrates the creation and initiation of a `javax.swing.Timer`. The timer is configured to trigger an `ActionEvent` every second. It highlights the fundamental process of defining the delay interval and providing an `ActionListener` to handle the events.

### Usage
```java
  int delay = 1000; //milliseconds
  ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
          //...Perform a task...
      }
  };
  new Timer(delay, taskPerformer).start();
```

### Parameters
- `delay` (int): The initial delay and the delay between event firing, in milliseconds.
- `taskPerformer` (ActionListener): The listener to receive the timer's action events.
```

--------------------------------

### Start JConsole for Specific Local Application Example

Source: https://docs.oracle.com/en/java/javase/26/management/using-jconsole.html

Example of starting JConsole to monitor a local application with process ID 2956.

```shell
% jconsole 2956
```

--------------------------------

### Example: Create Recording with Default Configuration

Source: https://docs.oracle.com/en/java/javase/26/docs/api/jdk.jfr/jdk/jfr/Recording.html

Demonstrates how to create a recording using the default configuration provided by the Configuration class. The recording is created in the NEW state and must be started.

```java
Recording r = new Recording(Configuration.getConfiguration("default"));
```

--------------------------------

### Get Thread CPU Time Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.management/java/lang/management/ThreadMXBean.html

Example of how to get the CPU time for a specific thread ID. This is the underlying method called by getCurrentThreadCpuTime.

```java
getThreadCpuTime(Thread.currentThread().threadId());
```

--------------------------------

### Example: Setting Display Mode and Full-Screen

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/java/awt/GraphicsDevice.html

Demonstrates how to set a new display mode and enter full-screen mode using a Frame. Includes checks for support and fallback to non-full-screen mode.

```java
Frame frame;
DisplayMode newDisplayMode;
GraphicsDevice gd;
// create a Frame, select desired DisplayMode from the list of modes
// returned by gd.getDisplayModes() ...

if (gd.isFullScreenSupported()) {
    gd.setFullScreenWindow(frame);
} else {
   // proceed in non-full-screen mode
   frame.setSize(...);
   frame.setLocation(...);
   frame.setVisible(true);
}

if (gd.isDisplayChangeSupported()) {
    gd.setDisplayMode(newDisplayMode);
}
```

--------------------------------

### Get Thread User Time Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.management/java/lang/management/ThreadMXBean.html

Example of how to get the user mode CPU time for a specific thread ID. This is the underlying method called by getCurrentThreadUserTime.

```java
getThreadUserTime(Thread.currentThread().threadId());
```

--------------------------------

### Run Main Application for MXBean Example

Source: https://docs.oracle.com/en/java/javase/26/jmx/essentials-jmx-api.html

Start the Main application that registers the MXBean. This application will wait for a JMX client to connect.

```bash
$ java com.example.mxbeans.Main

```

--------------------------------

### Get Recording Start Time

Source: https://docs.oracle.com/en/java/javase/26/docs/api/jdk.jfr/jdk/jfr/Recording.html

Returns the timestamp when the recording was started. Returns null if the recording has not yet been started.

```java
public Instant getStartTime()
```

--------------------------------

### Installation and Initialization

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/plaf/synth/SynthTreeUI.html

Methods responsible for installing UI components, defaults, listeners, and keyboard actions.

```APIDOC
## installComponents

### Description
Installs the subcomponents of the tree, which is the renderer pane.

### Method
protected void

### Signature
`protected void installComponents()`
```

```APIDOC
## installDefaults

### Description
Installs default properties.

### Method
protected void

### Signature
`protected void installDefaults()`
```

```APIDOC
## installKeyboardActions

### Description
Registers keyboard actions.

### Method
protected void

### Signature
`protected void installKeyboardActions()`
```

```APIDOC
## installListeners

### Description
Registers listeners.

### Method
protected void

### Signature
`protected void installListeners()`
```

--------------------------------

### Starting a new process

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/ProcessBuilder.html

Demonstrates how to start a new process with a command and arguments using the default working directory and environment.

```APIDOC
## Starting a new process

### Description
Starts a new operating system process with the specified command and arguments. This method uses the default working directory and environment of the current process.

### Method
`start()`

### Parameters
None directly in this example, but the `ProcessBuilder` instance is configured with a command and its arguments.

### Request Example
```java
Process p = new ProcessBuilder("myCommand", "myArg").start();
```

### Response
Returns a `Process` object representing the newly started subprocess.
```

--------------------------------

### Get Installed Attach Providers

Source: https://docs.oracle.com/en/java/javase/26/docs/api/jdk.attach/com/sun/tools/attach/spi/class-use/AttachProvider.html

Retrieves a list of all installed attach providers.

```APIDOC
## AttachProvider.providers()

### Description
Returns a list of the installed attach providers.

### Method
`static List<AttachProvider>`

### Returns
A `List` of `AttachProvider` instances.
```

--------------------------------

### macOS x64 JDK Installer Filename

Source: https://docs.oracle.com/en/java/javase/26/install/installation-jdk-macos.html

Example filename for a macOS x64 JDK installer package.

```text
jdk-26_macos-x64_bin.dmg
```

--------------------------------

### UI Installation Methods

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/plaf/basic/BasicMenuItemUI.html

Methods for installing UI components, defaults, keyboard actions, and listeners.

```APIDOC
## installComponents(JMenuItem menuItem)

### Description
Registers the subcomponents of the menu.

### Method
`protected void installComponents(JMenuItem menuItem)`

### Parameters
* **menuItem** (JMenuItem) - The menu item to install components for.
```

```APIDOC
## installDefaults()

### Description
Installs default properties.

### Method
`protected void installDefaults()`
```

```APIDOC
## installKeyboardActions()

### Description
Registers keyboard action.

### Method
`protected void installKeyboardActions()`
```

```APIDOC
## installListeners()

### Description
Registers listeners.

### Method
`protected void installListeners()`
```

--------------------------------

### Example Usage of open(Path, OpenOption...)

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/nio/channels/AsynchronousFileChannel.html

Demonstrates how to call the open method with specific options. This example shows opening a file for writing and creating it if it doesn't exist.

```java
AsynchronousFileChannel ch = AsynchronousFileChannel.open(file, StandardOpenOption.WRITE, StandardOpenOption.CREATE);

```

--------------------------------

### macOS aarch64 JDK Installer Filename

Source: https://docs.oracle.com/en/java/javase/26/install/installation-jdk-macos.html

Example filename for a macOS aarch64 (64-bit ARM) JDK installer package.

```text
jdk-26_macos-aarch64_bin.dmg
```

--------------------------------

### Create and Use Relation Service with Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.management/javax/management/relation/package-summary.html

Demonstrates the setup and usage of the Relation Service, including creating a relation type, registering MBeans, and creating a relation instance. It also shows how to query for associated MBeans.

```java
import java.util.*;
import javax.management.*;
import javax.management.relation.*;

// ...
MBeanServer mbs = ...;

// Create the Relation Service MBean
ObjectName relSvcName = new ObjectName(":type=RelationService");
RelationService relSvcObject = new RelationService(true);
mbs.registerMBean(relSvcObject, relSvcName);

// Create an MBean proxy for easier access to the Relation Service
RelationServiceMBean relSvc =
    MBeanServerInvocationHandler.newProxyInstance(mbs, relSvcName,
                          RelationServiceMBean.class,
                          false);

// Define the DependsOn relation type
RoleInfo[] dependsOnRoles = {
    new RoleInfo("dependent", Module.class.getName()),
    new RoleInfo("dependedOn", Module.class.getName())
};
relSvc.createRelationType("DependsOn", dependsOnRoles);

// Now define a relation instance "moduleA DependsOn moduleB"

ObjectName moduleA = new ObjectName(":type=Module,name=A");
ObjectName moduleB = new ObjectName(":type=Module,name=B");

Role dependent = new Role("dependent", Collections.singletonList(moduleA));
Role dependedOn = new Role("dependedOn", Collections.singletonList(moduleB));
Role[] roleArray = {dependent, dependedOn};
RoleList roles = new RoleList(Arrays.asList(roleArray));
relSvc.createRelation("A-DependsOn-B", "DependsOn", roles);

// Query the Relation Service to find what modules moduleA depends on
Map<ObjectName,List<String>> dependentAMap =
    relSvc.findAssociatedMBeans(moduleA, "DependsOn", "dependent");
Set<ObjectName> dependentASet = dependentAMap.keySet();
// Set of ObjectName containing moduleB

```

--------------------------------

### Get Character Range Start PC

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/classfile/attribute/CharacterRangeInfo.html

Retrieve the inclusive start index within the code array for this character range entry.

```java
int startPc()
```

--------------------------------

### Example Configuration Entry

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/javax/security/auth/login/Configuration.html

This example demonstrates a concrete Configuration entry, specifying LoginModules, their flags, and module-specific options with system property expansion.

```plaintext
Login {
  com.sun.security.auth.module.UnixLoginModule required;
  com.sun.security.auth.module.Krb5LoginModule optional
                  useTicketCache="true"
                  ticketCache="${user.home}${/}tickets";
};

```

--------------------------------

### MBean Example Server.java (Excerpt 1)

Source: https://docs.oracle.com/en/java/javase/26/jmx/jmx-connectors.html

This code excerpt from Server.java demonstrates the initialization of an MBean server, creation and registration of standard and dynamic MBeans, and initial management operations.

```Java
public class Server {

 public static void main(String[] args) {
     try {

         MBeanServer mbs = MBeanServerFactory.createMBeanServer();
         waitForEnterPressed();

         String domain = mbs.getDefaultDomain();
         waitForEnterPressed();

         String mbeanClassName = "SimpleStandard";
         String mbeanObjectNameStr =
             domain + ":type=" + mbeanClassName + ",name=1";
         ObjectName mbeanObjectName =
             createSimpleMBean(mbs, mbeanClassName, mbeanObjectNameStr);
         waitForEnterPressed();

         printMBeanInfo(mbs, mbeanObjectName, mbeanClassName);
         waitForEnterPressed();

         manageSimpleMBean(mbs, mbeanObjectName, mbeanClassName);
         waitForEnterPressed();

         mbeanClassName = "SimpleDynamic";
         mbeanObjectNameStr =
             domain + ":type=" + mbeanClassName + ",name=1";
         mbeanObjectName =
             createSimpleMBean(mbs, mbeanClassName, mbeanObjectNameStr);
         waitForEnterPressed();

         printMBeanInfo(mbs, mbeanObjectName, mbeanClassName);
         waitForEnterPressed();

         manageSimpleMBean(mbs, mbeanObjectName, mbeanClassName);
         waitForEnterPressed();

         [...]


```

--------------------------------

### getIndex

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/SizeSequence.html

Gets the index of an entry based on its starting position.

```APIDOC
## getIndex(int position)

### Description
Returns the index of the entry that corresponds to the specified position. For example, `getIndex(0)` is 0, since the first entry always starts at position 0.

### Parameters
* `position` - the position of the entry

### Returns
the index of the entry that occupies the specified position
```

--------------------------------

### getPosition

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/SizeSequence.html

Gets the starting position of an entry based on its index.

```APIDOC
## getPosition(int index)

### Description
Returns the start position for the specified entry. For example, `getPosition(0)` returns 0, `getPosition(1)` is equal to `getSize(0)`, `getPosition(2)` is equal to `getSize(0)` + `getSize(1)`, and so on. Note that if `index` is greater than `length` the value returned may be meaningless.

### Parameters
* `index` - the index of the entry whose position is desired

### Returns
the starting position of the specified entry
```

--------------------------------

### Getting Class Object Using Class Literal

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/Class.html

This example shows how to get the Class object for a named class using a class literal.

```APIDOC
## Getting Class Object Using Class Literal

### Description
This example shows how to get the Class object for a named class using a class literal, as described in JLS 15.8.2.

### Example Usage
```java
System.out.println("The name of class Foo is: " + Foo.class.getName());
```
```

--------------------------------

### Get Substring with Start and End Indices

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/StringBuilder.html

Extracts a substring from the specified start index (inclusive) to the character at index end - 1 (exclusive).

```java
public String substring(int start, int end)
```

--------------------------------

### setupMenuOpenKey

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/plaf/basic/BasicInternalFrameUI.html

Sets up the key binding for opening the menu.

```APIDOC
## setupMenuOpenKey

### Description
Setup the menu open key.

### Method
protected void setupMenuOpenKey()
```

--------------------------------

### Get Substring from Start to End

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/StringBuilder.html

Extracts a substring from the specified start index (inclusive) to the end of the sequence. This method is part of the CharSequence interface.

```java
public String substring(int start)
```

--------------------------------

### Configuration Syntax Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/javax/security/auth/login/Configuration.html

This example demonstrates the default syntax for a Configuration entry, specifying LoginModules, their flags, and options for a given application name.

```APIDOC
## Configuration Syntax

### Description
This section illustrates the default syntax for defining a login configuration, which includes application-specific entries and a default entry for 'other'.

### Syntax Example
```
     Name { 
           ModuleClass  Flag    ModuleOptions;
           ModuleClass  Flag    ModuleOptions;
           ModuleClass  Flag    ModuleOptions;
     };
     Name { 
           ModuleClass  Flag    ModuleOptions;
           ModuleClass  Flag    ModuleOptions;
     };
     other { 
           ModuleClass  Flag    ModuleOptions;
           ModuleClass  Flag    ModuleOptions;
     };
```

### Flag Semantics

- **Required**: The LoginModule must succeed. Authentication continues regardless of success or failure.
- **Requisite**: The LoginModule must succeed. If it fails, authentication stops immediately. If it succeeds, authentication continues.
- **Sufficient**: The LoginModule does not need to succeed. If it succeeds, authentication stops immediately. If it fails, authentication continues.
- **Optional**: The LoginModule does not need to succeed. Authentication continues regardless of success or failure.

### Module Options

_ModuleOptions_ are space-separated key-value pairs passed to the LoginModule, e.g., `debug="true"`. System properties like `${system.property}` can be expanded within values.
```

--------------------------------

### Abstract Method Overriding Example

Source: https://docs.oracle.com/en/java/javase/26/docs/specs/jls/jls-8.html

Demonstrates how an abstract method can be overridden in a subclass, potentially refining the set of exceptions thrown. This example shows an interface `Buffer` with a `get` method, an abstract class `InfiniteBuffer` that implements `Buffer` and overrides `get` to throw fewer exceptions.

```java
class BufferEmpty extends Exception {
    BufferEmpty() { super(); }
    BufferEmpty(String s) { super(s); }
}
class BufferError extends Exception {
    BufferError() { super(); }
    BufferError(String s) { super(s); }
}
interface Buffer {
    char get() throws BufferEmpty, BufferError;
}
abstract class InfiniteBuffer implements Buffer {
    public abstract char get() throws BufferError;
}
```

--------------------------------

### Get Encoded Character Range Start

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/classfile/attribute/CharacterRangeInfo.html

Retrieve the encoded start of character positions in the source file, inclusive. The encoding is `lineNumber << 10 + columnNumber`.

```java
int characterRangeStart()
```

--------------------------------

### Instantiate LoginContext (Tutorial Specific)

Source: https://docs.oracle.com/en/java/javase/26/security/jaas-authentication-tutorial.html

Demonstrates the specific instantiation of LoginContext used in the tutorial, with 'Sample' as the config entry and MyCallbackHandler.

```java
import javax.security.auth.login.*;
// ...
LoginContext lc =
    new LoginContext("Sample",
          new MyCallbackHandler());

```

--------------------------------

### getSelectionStart

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/java/awt/TextComponent.html

Gets the start position of the selected text in this text component.

```APIDOC
## getSelectionStart

### Description
Gets the start position of the selected text in this text component.

### Method
public int getSelectionStart()

### Returns
* The start position of the selected text.
```

--------------------------------

### Java Example Provider Implementation

Source: https://docs.oracle.com/en/java/javase/26/security/pkcs11-reference-guide1.html

Demonstrates implementing multiple algorithms in a single class, handling concurrent provider instances, and managing unextractable keys.

```java
package com.foo;

import java.io.*;
import java.lang.reflect.*;
import java.security.*;
import javax.crypto.*;

/**
 * Example provider that demonstrates some Provider class features.
 *
 *  . Implement multiple different algorithms in a single class.
 *    Previously each algorithm needed to be implemented in a separate class
 *    (e.g. one for SHA-256, one for SHA-384, etc.)
 *
 *  . Multiple concurrent instances of the provider frontend class each
 *    associated with a different backend.
 *
 *  . It uses "unextractable" keys and lets the framework know which key
 *    objects it can and cannot support
 *
 * Note that this is only a simple example provider designed to demonstrate
 * several of the new features. It is not explicitly designed for efficiency.
 */
public final class ExampleProvider extends Provider {

    // Reference to the crypto backend that implements all the algorithms.
    final CryptoBackend cryptoBackend;

    public ExampleProvider(String name, CryptoBackend cryptoBackend) {
        super(name, 1.0, "JCA/JCE provider for " + name);
        this.cryptoBackend = cryptoBackend;
        // register the algorithms we support (SHA-256, SHA-384, and AES)
        putService(new MyService
            (this, "MessageDigest", "SHA-256", "com.foo.ExampleProvider$MyMessageDigest"));
        putService(new MyService
            (this, "MessageDigest", "SHA-384", "com.foo.ExampleProvider$MyMessageDigest"));
        putService(new MyCipherService
            (this, "Cipher", "AES", "com.foo.ExampleProvider$MyCipher"));
    }

    // The API of our fictitious crypto backend.
    static abstract class CryptoBackend {
        abstract byte[] digest(String algorithm, byte[] data);
        abstract byte[] encrypt(String algorithm, KeyHandle key, byte[] data);
        abstract byte[] decrypt(String algorithm, KeyHandle key, byte[] data);
        abstract KeyHandle createKey(String algorithm, byte[] keyData);
    }

    // The shell of the representation the crypto backend uses for keys.
    private static final class KeyHandle {
        // fill in code
    }

    // We have our own ServiceDescription implementation that overrides newInstance()
    // that calls the (Provider, String) constructor instead of the no-args constructor.
    private static class MyService extends Service {

        private static final Class[] paramTypes = {Provider.class, String.class};

        MyService(Provider provider, String type, String algorithm,
                String className) {
            super(provider, type, algorithm, className, null, null);
        }

        public Object newInstance(Object param) throws NoSuchAlgorithmException {
            try {
                // Get the Class object for the implementation class.
                Class clazz;
                Provider provider = getProvider();
                ClassLoader loader = provider.getClass().getClassLoader();
                if (loader == null) {
                    clazz = Class.forName(getClassName());
                } else {
                    clazz = loader.loadClass(getClassName());
                }
                // Fetch the (Provider, String) constructor.
                Constructor cons = clazz.getConstructor(paramTypes);
                // Invoke constructor and return the SPI object.
                Object obj = cons.newInstance(new Object[] {provider, getAlgorithm()});
                return obj;
            } catch (Exception e) {
                throw new NoSuchAlgorithmException("Could not instantiate service", e);
            }
        }
    }

```

--------------------------------

### getRunStart

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/text/Bidi.html

Gets the starting character index of a specific logical run.

```APIDOC
## getRunStart

### Description
Return the index of the character at the start of the nth logical run in this line, as an offset from the start of the line.

### Method
public int getRunStart(int run)

### Parameters
#### Path Parameters
* **run** (int) - the index of the run, between 0 and `getRunCount()`

### Returns
the start of the run
```

--------------------------------

### Instantiating KeyStore

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/security/KeyStore.html

Demonstrates different ways to obtain a KeyStore instance, including specifying an existing file, using the default type, or providing a specific keystore type.

```APIDOC
## Instantiating KeyStore

### Description
Demonstrates different ways to obtain a KeyStore instance.

### Examples

1.  **Specify an existing keystore file:**
    ```java
    // get keystore password
    char[] password = getPassword();

    // probe the keystore file and load the keystore entries
    KeyStore ks = KeyStore.getInstance(new File("keyStoreName"), password);
    ```
    The system probes the specified file to determine its keystore type and returns a keystore implementation with its entries already loaded. The `load` method does not need to be called in this case.

2.  **Rely on the default type:**
    ```java
    KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
    ```
    The system returns a keystore implementation for the default type.

3.  **Provide a specific keystore type:**
    ```java
    KeyStore ks = KeyStore.getInstance("JKS");
    ```
    The system returns the most preferred implementation of the specified keystore type available in the environment.
```

--------------------------------

### JMX Tutorial README

Source: https://docs.oracle.com/en/java/javase/26/jmx/jmx-essentials-example.html

This README file outlines the JMX tutorial's introductory example. It explains how to compile and run the Java classes, start the main application, and use jconsole for remote operations. Assumes Java SE 6 on Unix with korn shell.

```shell
# ==============================================================================
#
#  JMX Tutorial Introductory Example : Instrumenting Your Own Applications.
#
#  The aim of this introductory example is to show the basic features of
#  the JMX technology first by instrumenting a simple resource and second
#  by performing operations on it using the jconsole tool. This example
#  shows the implementation of a standard MBean, how to register it in the
#  platform's MBean Server and how to perform remote operations on it by
#  connecting to the RMI connector server using the jconsole tool. Besides
#  monitoring the application, jconsole will also allow you to observe the
#  built-in JVM instrumentation as the JVM's MBeans are also registered in
#  the platform's MBean Server. This examples also shows how the existing
#  platform's MBean Server can be shared between the JVM and the application
#  itself to register the application MBeans, thus avoiding the creation of
#  multiple MBean Server instances on the same JVM.
#
# ==============================================================================
#
# In order to compile and run the example, make a copy of this README file, and
# then simply cut and paste all the commands as needed into a terminal window.
#
# This README makes the assumption that you are running under Java SE 6 on Unix,
# you are familiar with the JMX technology, and with the bourne shell or korn
# shell syntax.
#
# All the commands below are defined using Unix korn shell syntax.
#
# If you are not running Unix and korn shell you are expected to be able to
# adapt these commands to your favorite OS and shell environment.
#

# Compile Java classes
#
# The Java classes used in this example are contained in the com.example.mbeans
# Java package.
#
# * Main.java: gets the Platform MBean Server, and creates
#              and registers the Hello World MBean on it.
#
# * Hello.java: implements the Hello World standard MBean.
#
# * HelloMBean.java: the management interface exposed by
#                    the Hello World standard MBean.
#

javac com/example/mbeans/*.java

# Start the Main application
#

java com.example.mbeans.Main

# Start jconsole on a different shell window on the same machine
#
# JConsole is located in $(J2SE_HOME)/bin/jconsole
#

jconsole

# ==============================================================================

```

--------------------------------

### Example RowFilter: Starts With 'a'

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/RowFilter.html

Implement a RowFilter to include entries where at least one column's string value starts with 'a'. This is useful for basic text-based filtering.

```java
RowFilter<Object,Object> startsWithAFilter = new RowFilter<Object,Object>() {
  public boolean include(Entry<? extends Object, ? extends Object> entry) {
    for (int i = entry.getValueCount() - 1; i >= 0; i--) {
      if (entry.getStringValue(i).startsWith("a")) {
        // The value starts with "a", include it
        return true;
      }
    }
    // None of the columns start with "a"; return false so that this
    // entry is not shown
    return false;
  }
};

```

--------------------------------

### Starting a New Process with ProcessBuilder

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/ProcessBuilder.html

This snippet demonstrates how to start a new operating system process with a specified command and arguments. It uses the default working directory and environment.

```java
Process p = new ProcessBuilder("myCommand", "myArg").start();
```

--------------------------------

### Thread Creation and Starting with Thread.Builder

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/Thread.html

Examples demonstrating the use of Thread.Builder for creating and starting platform and virtual threads, including daemon threads and custom naming.

```APIDOC
## Thread.Builder Usage

### Description
Demonstrates creating and starting threads using the `Thread.Builder` API, including platform and virtual threads, daemon threads, and custom naming.

### Code Examples

```java
Runnable runnable = ...;

// Start a daemon thread to run a task
Thread thread = Thread.ofPlatform().daemon().start(runnable);

// Create an unstarted thread with name "duke", its start() method must be invoked to schedule it to execute.
Thread thread = Thread.ofPlatform().name("duke").unstarted(runnable);

// A ThreadFactory that creates daemon threads named "worker-0", "worker-1", ...
ThreadFactory factory = Thread.ofPlatform().daemon().name("worker-", 0).factory();

// Start a virtual thread to run a task
Thread thread = Thread.ofVirtual().start(runnable);

// A ThreadFactory that creates virtual threads
ThreadFactory factory = Thread.ofVirtual().factory();
```
```

--------------------------------

### Start Process with Modified Directory, Environment, and Redirected Output

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/lang/ProcessBuilder.html

This example demonstrates how to start a process with a custom working directory, modified environment variables, and redirects both standard output and error to be appended to a log file. It also includes assertions to verify the redirection settings and the initial state of the process's input stream.

```java
ProcessBuilder pb = new ProcessBuilder("myCommand", "myArg1", "myArg2");
Map<String, String> env = pb.environment();
env.put("VAR1", "myValue");
env.remove("OTHERVAR");
env.put("VAR2", env.get("VAR1") + "suffix");

pb.directory(new File("myDir"));
File log = new File("log");
pb.redirectErrorStream(true);
pb.redirectOutput(Redirect.appendTo(log));

Process p = pb.start();
assert pb.redirectInput() == Redirect.PIPE;
assert pb.redirectOutput().file() == log;
assert p.getInputStream().read() == -1;
```

--------------------------------

### BasicToolTipUI.installDefaults

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/class-use/JComponent.html

Installs default properties for the tooltip UI.

```APIDOC
## installDefaults(JComponent c)

### Description
Installs default properties.

### Method
`protected void`
```

--------------------------------

### SwingWorker get() with Modal Dialog Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/SwingWorker.html

Illustrates how to use get() on the Event Dispatch Thread by recommending a modal dialog to prevent blocking UI events.

```java
class SwingWorkerCompletionWaiter implements PropertyChangeListener {
    private JDialog dialog;

    public SwingWorkerCompletionWaiter(JDialog dialog) {
        this.dialog = dialog;
    }

```

--------------------------------

### get(int index, char[] dst)

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/nio/CharBuffer.html

Reads characters from this buffer into a destination character array starting at a specified index. This is an absolute bulk get operation.

```APIDOC
## get(int index, char[] dst)

### Description
Reads characters from this buffer into the given destination array, starting at the specified index in the buffer. The buffer's position remains unchanged. This method is equivalent to calling `get(index, dst, 0, dst.length)`.

### Method
public CharBuffer get(int index, char[] dst)

### Parameters
#### Path Parameters
* **index** (int) - The starting index in this buffer from which to read.
* **dst** (char[]) - The destination array to write characters into.

### Throws
* **IndexOutOfBoundsException** - If `index` is negative, not smaller than `limit()`, or if `limit() - index` is less than `dst.length`.
```

--------------------------------

### getTextStart() - Get Text Start Offset

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.xml/javax/xml/stream/XMLStreamReader.html

Retrieves the starting offset of the current text event within the character array. This method is only valid for text-related states.

```Java
int getTextStart()
Returns the offset into the text character array where the first character (of this text event) is stored. 

Returns:
    the starting position of the text in the character array 

Throws:
    `IllegalStateException` - if this state is not a valid text state.
```

--------------------------------

### Example Usage

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/java/awt/SystemTray.html

Demonstrates how to access and customize the system tray with a TrayIcon.

```java
    TrayIcon trayIcon = null;
    if (SystemTray.isSupported()) {
        // get the SystemTray instance
        SystemTray tray = SystemTray.getSystemTray();
        // load an image
        Image image = Toolkit.getDefaultToolkit().getImage("path/to/your/image.png");
        // create a action listener to listen for default action executed on the tray icon
        ActionListener listener = new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // execute default action of the application
                System.out.println("Default action performed!");
            }
        };
        // create a popup menu
        PopupMenu popup = new PopupMenu();
        // create menu item for the default action
        MenuItem defaultItem = new MenuItem("Show Application");
        defaultItem.addActionListener(listener);
        popup.add(defaultItem);
        // construct a TrayIcon
        trayIcon = new TrayIcon(image, "Tray Demo", popup);
        // set the TrayIcon properties
        trayIcon.addActionListener(listener);
        trayIcon.setToolTip("Right-click for options");
        // add the tray image
        try {
            tray.add(trayIcon);
            System.out.println("TrayIcon added successfully.");
        } catch (AWTException e) {
            System.err.println("TrayIcon could not be added: " + e.getMessage());
        }
    } else {
        // disable tray option in your application or
        // perform other actions
        System.err.println("System tray is not supported on this platform.");
    }
    // ...
    // some time later
    // the application state has changed - update the image
    if (trayIcon != null) {
        // Image updatedImage = Toolkit.getDefaultToolkit().getImage("path/to/updated/image.png");
        // trayIcon.setImage(updatedImage);
    }
    // ...
    // To remove the tray icon when the application exits:
    // if (trayIcon != null) {
    //     tray.remove(trayIcon);
    // }
```

--------------------------------

### UI Installation and Uninstallation

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/plaf/synth/SynthTreeUI.html

Methods for preparing the UI delegate for installation and uninstallation, including setting up and tearing down components, defaults, and listeners.

```APIDOC
## prepareForUIInstall()

### Description
Invoked after the `tree` instance variable has been set, but before any defaults/listeners have been installed.

### Method
`protected void`
```

```APIDOC
## prepareForUIUninstall()

### Description
Invoked before uninstallation of UI.

### Method
`protected void`
```

```APIDOC
## uninstallComponents()

### Description
Uninstalls the renderer pane.

### Method
`protected void`
```

```APIDOC
## uninstallDefaults()

### Description
Uninstalls default properties.

### Method
`protected void`
```

```APIDOC
## uninstallKeyboardActions()

### Description
Unregisters keyboard actions.

### Method
`protected void`
```

```APIDOC
## uninstallListeners()

### Description
Unregisters listeners.

### Method
`protected void`
```

--------------------------------

### GetTimeResponse Implementation Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.naming/javax/naming/ldap/ExtendedRequest.html

Example implementation of the ExtendedResponse interface for a hypothetical 'get time' LDAP operation. This class handles decoding the response from the LDAP server.

```Java
public class GetTimeResponse implements ExtendedResponse {
    long time;
    public GetTimeResponse(String id, byte[] berValue, int offset,
        int length) throws NamingException {
        time =      ... // decode berValue to get time
    }
    public java.util.Date getDate() { return new java.util.Date(time) };
    public long getTime() { return time };
    ... 
 }
```

--------------------------------

### completeUIInstall

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/plaf/metal/MetalTreeUI.html

Called after all defaults and listeners have been installed during the UI installation process.

```APIDOC
## completeUIInstall()

### Description
Invoked from installUI after all the defaults/listeners have been installed.

### Method
`protected void`
```

--------------------------------

### Start Tasks with Phaser and Override onAdvance

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/util/concurrent/Phaser.html

Override onAdvance to control phase transitions. This example starts multiple tasks and waits for them to complete a specified number of iterations.

```java
void startTasks(List<Runnable> tasks, int iterations) {
  Phaser phaser = new Phaser() {
    protected boolean onAdvance(int phase, int registeredParties) {
      return phase >= iterations - 1 || registeredParties == 0;
    }
  };
  phaser.register();
  for (Runnable task : tasks) {
    phaser.register();
    new Thread(() -> {
      do {
        task.run();
        phaser.arriveAndAwaitAdvance();
      } while (!phaser.isTerminated());
    }).start();
  }
  // allow threads to proceed; don't wait for them
  phaser.arriveAndDeregister();
}
```

--------------------------------

### Installation and Initialization Methods

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/plaf/basic/BasicTreeUI.html

Methods used internally to set up and configure the BasicTreeUI.

```APIDOC
## installComponents

### Description
Installs the subcomponents of the tree, which is the renderer pane.

### Method
`protected void installComponents()`
```

```APIDOC
## installDefaults

### Description
Installs default properties.

### Method
`protected void installDefaults()`
```

```APIDOC
## installKeyboardActions

### Description
Registers keyboard actions.

### Method
`protected void installKeyboardActions()`
```

```APIDOC
## installListeners

### Description
Registers listeners.

### Method
`protected void installListeners()`
```

--------------------------------

### Menu Key Setup Methods

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/javax/swing/plaf/basic/BasicInternalFrameUI.html

Methods for setting up menu-related key actions.

```APIDOC
## setupMenuCloseKey()

### Description
Sets up the menu close key action.

### Method
protected void
```

```APIDOC
## setupMenuOpenKey()

### Description
Sets up the menu open key action.

### Method
protected void
```

--------------------------------

### Get Calendar Instance

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.base/java/util/Calendar.html

Use Calendar.getInstance() to get a Calendar object initialized with the current date and time. This is a common way to start working with dates and times in Java.

```java
Calendar rightNow = Calendar.getInstance();
```

--------------------------------

### GetTimeRequest Implementation Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.naming/javax/naming/ldap/ExtendedRequest.html

Example implementation of the ExtendedRequest interface for a hypothetical 'get time' LDAP operation. This class is used to construct the request sent to the LDAP server.

```Java
public class GetTimeRequest implements ExtendedRequest {
    public GetTimeRequest() {... };
    public ExtendedResponse createExtendedResponse(String id,
        byte[] berValue, int offset, int length)
        throws NamingException {
        return new GetTimeResponse(id, berValue, offset, length);
    }
    ... 
 }
```

--------------------------------

### Window Constructor Example

Source: https://docs.oracle.com/en/java/javase/26/docs/api/java.desktop/java/awt/Window.html

Demonstrates how to construct a Window object, specifying its owner and graphics configuration. It also shows how to correctly set the window's location considering the screen's bounds.

```APIDOC
## Window Constructor

### Description
Constructs a new, invisible Window object with the specified owner window and a specified GraphicsConfiguration. The owner must be specified, and the GraphicsConfiguration must be one of the configurations of the target screen device.

### Method Signature
`Window(Window owner, GraphicsConfiguration gc)`

### Parameters
*   `owner` (Window) - The owner of the window.
*   `gc` (GraphicsConfiguration) - The graphics configuration of the screen on which the window is displayed.

### Usage Example
```java
// Assuming 'ownerWindow' is an existing Window object and 'screenConfig' is a GraphicsConfiguration
Rectangle bounds = screenConfig.getBounds();
Window w = new Window(ownerWindow, screenConfig);
w.setLocation(10 + bounds.x, 10 + bounds.y);
```

### Notes
*   The location and size of top-level windows are requests to the window management system and may be modified.
*   Visual effects applied by the desktop window management system are outside the control of AWT.
```

--------------------------------

### Start Application with SSL Keystore Properties

Source: https://docs.oracle.com/en/java/javase/26/management/monitoring-and-management-using-jmx-technology.html

Launch this Java application with the specified command to enable SSL and provide keystore credentials. Ensure the keystore and password properties are correctly set.

```bash
java -Djavax.net.ssl.keyStore=keystore \
     -Djavax.net.ssl.keyStorePassword=password \
     com.example.MyApp

```

--------------------------------

### Start JShell in Verbose Mode

Source: https://docs.oracle.com/en/java/javase/26/jshell/introduction-jshell.html

Use the '-v' option with the 'jshell' command to start the tool in verbose mode. This mode is recommended for tutorials to ensure output matches examples.

```bash
% jshell -v

```

--------------------------------

### Execute SampleClient with Kerberos Configuration

Source: https://docs.oracle.com/en/java/javase/26/security/use-java-gss-api-secure-message-exchanges-without-jaas-programming.html

Launch the SampleClient application, providing Kerberos realm and KDC details via system properties. This configuration enables the client to use the specified Kerberos setup for secure communication.

```shell
-Djava.security.krb5.realm=<your_realm> -Djava.security.krb5.kdc=<your_kdc> -Djavax.security.auth.useSubjectCredsOnly=false -Djava.security.auth.login.config=bcsLogin.conf
```

--------------------------------

### Start JShell

Source: https://docs.oracle.com/en/java/javase/26/jshell/introduction-jshell.html

Enter the 'jshell' command on the command line to start the Java Shell tool. Ensure JDK 9 or higher is installed and accessible in your system's PATH.

```bash
% jshell
|  Welcome to JShell -- Version 17.0.1
|  For an introduction type: /help intro

jshell>
```
Tokens:
Raw