### Install libffi

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

Type 'make install' to install the library and header files.

```bash
make install
```

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

### Makeinfo Command Not Found Error Example

Source: https://github.com/java-native-access/jna/blob/master/www/RaspberryPiDevelopmentEnvironment.md

This warning indicates that 'makeinfo' is missing, which is required for generating documentation. Install the 'texinfo' package to resolve this.

```bash
makeinfo: command not found
... WARNING: 'makeinfo' is missing on your system.
```

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

### Install Build Dependencies (Debian/Ubuntu)

Source: https://github.com/java-native-access/jna/blob/master/www/Contributing.md

Install necessary build tools on Debian-based systems using apt-get.

```bash
% apt-get install git ant openjdk-6-jdk make autotools gcc
```

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

### Install Development Tools with Homebrew

Source: https://github.com/java-native-access/jna/blob/master/www/MacDevelopmentEnvironment.md

Installs essential build tools like ant, autoconf, automake, libtool, and gettext using Homebrew.

```bash
brew install ant autoconf automake libtool gettext
```

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

### X11/Xlib.h Header Not Found Error Example

Source: https://github.com/java-native-access/jna/blob/master/www/RaspberryPiDevelopmentEnvironment.md

This error signifies that X11 development libraries are not installed. Install 'libx11-dev' and 'libxt-dev' to fix this issue.

```bash
fatal error: X11/Xlib.h: No such file or directory
```

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

### Configure libffi with specific installation prefix

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

Use the --prefix configure switch to specify a custom installation directory for libffi libraries and header files. Defaults to /usr/local.

```bash
./configure --prefix=/path/to/install
```

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

### Install Build Tools and X11 Libraries on Raspberry Pi

Source: https://github.com/java-native-access/jna/blob/master/www/RaspberryPiDevelopmentEnvironment.md

Installs necessary build tools and X11 libraries required for compiling JNA on Raspberry Pi. Ensure you have internet connectivity and sudo privileges.

```bash
sudo apt-get install autoconf automake libtool libx11-dev libxt-dev texinfo
```

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

### Winspool Utility API Example

Source: https://github.com/java-native-access/jna/blob/master/www/Contributing.md

Abstract class for Winspool utility functions. This example shows the signature for retrieving printer information.

```java
/**
 * Winspool Utility API.
 * @author dblock[at]dblock.org
 */
public abstract class WinspoolUtil {
  public static PRINTER_INFO_1[] getPrinterInfo1() {
    
  }
}
```

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

### Troubleshooting Missing Build Tools

Source: https://github.com/java-native-access/jna/blob/master/www/MacDevelopmentEnvironment.md

Illustrates build errors that occur when essential tools like autoconf, automake, or libtool are missing. These can be installed using Homebrew.

```bash
$ brew install autoconf automake libtool gettext
```

```bash
native:
     [exec] Generating configure
     [exec] ./autogen.sh: line 2: exec: autoreconf: not found
```

```bash
[exec] Can't exec "aclocal": No such file or directory at /usr/local/Cellar/autoconf/2.69/share/autoconf/Autom4te/FileUtils.pm line 326.
[exec] autoreconf: failed to run aclocal: No such file or directory
```

```bash
[exec] configure.ac:41: error: possibly undefined macro: AC_PROG_LIBTOOL
```

```bash
native:
    [exec] Configuring libffi (x86_64)
    [exec] configure: WARNING: unrecognized options: --enable-static, --disable-shared, --with-pic
    [exec] configure: error: cannot find install-sh, install.sh, or shtool in
```

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

### JNA Example in JRuby

Source: https://github.com/java-native-access/jna/blob/master/www/DynamicallyTypedLanguages.md

This example shows how to use JNA from JRuby to access C standard library functions like puts, printf, open, write, fopen, fprintf, fflush, and fclose. It dynamically retrieves functions from the 'c' native library.

```jruby
require 'java'

module Libc
  @@lib = com.sun.jna.NativeLibrary.getInstance("c")
  @@ptr_funcs = [ 'fopen', 'malloc', 'calloc' ]
  def self.method_missing(meth, *args)
    if @@ptr_funcs.include?(meth.to_s)
      @@lib.getFunction(meth.to_s).invokePointer(args.to_java)
    else
      @@lib.getFunction(meth.to_s).invokeInt(args.to_java)
    end
  end
  O_RDONLY = 0
  O_WRONLY = 1
  O_RDWR = 2
end

Libc.puts("puts from libc")
Libc.printf("Hello %s, from printf\n", "World")

file = Libc.open("/dev/stdout", 1, Libc::O_WRONLY)
n = Libc.write(file, "Test\n", 5)
puts "Wrote #{n} bytes via Libc"

path = "/dev/stdout"
fp = Libc.fopen(path, "w+")
Libc.fprintf(fp, "fprintf to %s via stdio\n", path)
Libc.fflush(fp)
Libc.fclose(fp)
```

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

### Run libffi tests

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

Execute 'make check' to verify that libffi is functioning correctly. This requires DejaGNU to be installed.

```bash
make check
```

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

### Initialize Visual Studio Build Environment for ARM64 Target on x64 Host

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Execute the vcvarsall.bat script to set up the environment for building ARM64 applications on a 64-bit (x64) host using the Visual Studio C++ compiler. Adjust the path to vcvarsall.bat based on your Visual Studio installation.

```cmd
"C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat" x64_arm64
```

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

### Initialize Visual Studio Build Environment for x64

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Execute the vcvarsall.bat script to set up the environment for building 64-bit (x64) applications using the Visual Studio C++ compiler. Adjust the path to vcvarsall.bat based on your Visual Studio installation.

```cmd
"C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat" x64
```

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

### Solaris Environment Setup for JNA Native Library Build

Source: https://github.com/java-native-access/jna/blob/master/www/BuildingNativeLibraries.md

Sets up the environment variables for building JNA native libraries on Solaris, ensuring the correct make utility and path are configured.

```bash
# Ensure `gmake` is used
export MAKE=gmake
# Place local binaries on the path
export PATH=$HOME/local/bin:$PATH
```

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

### Initialize Visual Studio Build Environment for x86 Target on x64 Host

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Execute the vcvarsall.bat script to set up the environment for building 32-bit (x86) applications on a 64-bit (x64) host using the Visual Studio C++ compiler. Adjust the path to vcvarsall.bat based on your Visual Studio installation.

```cmd
"C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat" x64_x86
```

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

### Build JNA for FreeBSD x86

Source: https://github.com/java-native-access/jna/blob/master/www/FreeBSD.md

Steps to build the JNA native library for FreeBSD x86. This involves setting up a FreeBSD VM, installing dependencies, and compiling the library using Ant.

```bash
# Fetch image
wget https://download.freebsd.org/releases/VM-IMAGES/13.2-RELEASE/i386/Latest/FreeBSD-13.2-RELEASE-i386.qcow2.xz

```

```bash
xz -d FreeBSD-13.2-RELEASE-i386.qcow2.xz

```

```bash
# Ensure there is enough space in the image
qemu-img resize -f qcow2 FreeBSD-13.2-RELEASE-i386.qcow2 +5G

```

```bash
# Launch image
qemu-system-i386 -m 3096M -drive file=FreeBSD-13.2-RELEASE-i386.qcow2

```

```bash
gpart show /dev/ada0
gpart recover /dev/ada0
gpart show /dev/ada0
gpart resize -i 4 /dev/ada0
growfs /

```

```bash
# Exit single user mode (BSD boots to multi-user)
exit

```

```bash
# Login as root

```

```bash
# Set keyboard configuration
kbdmap

```

```bash
# Set current date and time (YYYYMMDDHHMM)
date 202403081928

```

```bash
# Install prerequisites - part 1 - java, build system, rsync
pkg install openjdk17 wget automake rsync gmake gcc bash texinfo
# Adjust fstab (optional, only needed if reboot is planned)
# fdesc   /dev/fd         fdescfs         rw      0       0
# proc    /proc           procfs          rw      0       0

```

```bash
# Install prerequisites - part 2 - ant
wget https://dlcdn.apache.org/ant/binaries/apache-ant-1.10.14-bin.zip
unzip apache-ant-1.10.14-bin.zip

```

```bash
# Transfer JNA source code to build environment
rsync -av --exclude=.git USER@BUILD_HOST:src/jnalib/ jnalib/

```

```bash
# Build JNA and run unittests
cd jnalib
chmod +x native/libffi/configure native/libffi/install-sh
/root/apache-ant-1.10.14/bin/ant

```

```bash
# Copy jna native library back to host system
scp lib/native/freebsd-x86.jar USER@BUILD_HOST:src/jnalib/lib/native

```

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

### Build JNA for FreeBSD aarch64

Source: https://github.com/java-native-access/jna/blob/master/www/FreeBSD.md

Steps to build the JNA native library for FreeBSD aarch64. This involves setting up a FreeBSD VM, installing dependencies, and compiling the library using Ant.

```bash
# Fetch FreeBSD 13.2 image and extract it
wget https://download.freebsd.org/releases/VM-IMAGES/13.2-RELEASE/aarch64/Latest/FreeBSD-13.2-RELEASE-arm64-aarch64.qcow2.xz

```

```bash
xz -d FreeBSD-13.2-RELEASE-arm64-aarch64.qcow2.xz

```

```bash
# Ensure there is enough space in the image
qemu-img resize -f qcow2 FreeBSD-13.2-RELEASE-arm64-aarch64.qcow2 +5G

```

```bash
# Launch aarch64 emulator with downloaded image
qemu-system-aarch64 -m 4096M -cpu cortex-a57 -M virt  \
        -bios /usr/lib/u-boot/qemu_arm64/u-boot.bin \
        -serial telnet::4444,server -nographic \
        -drive if=none,file=FreeBSD-13.2-RELEASE-arm64-aarch64.qcow2,id=hd0 \
        -device virtio-blk-device,drive=hd0 \
        -device virtio-net-device,netdev=net0 \
        -netdev user,id=net0

```

```bash
# Connect to terminal for emulated system and boot into single user mode with default shell
telnet localhost 4444

```

```bash
# Resize partitions
gpart show /dev/vtbd0
gpart recover /dev/vtbd0
gpart show /dev/vtbd0
gpart resize -i 3 /dev/vtbd0
growfs /

```

```bash
# Exit single user mode (BSD boots to multi-user)
exit

```

```bash
# Login as root

```

```bash
# Set current date and time (YYYYMMDDHHMM)
date 202403081928

```

```bash
# Install prerequisites - part 1 - java, build system, rsync
pkg install openjdk17 wget automake rsync gmake gcc bash texinfo
# Adjust fstab (optional, only needed if reboot is planned)
# fdesc   /dev/fd         fdescfs         rw      0       0
# proc    /proc           procfs          rw      0       0

```

```bash
# Install prerequisites - part 2 - ant
wget https://dlcdn.apache.org/ant/binaries/apache-ant-1.10.14-bin.zip 
unzip apache-ant-1.10.14-bin.zip

```

```bash
# Transfer JNA source code to build environment
rsync -av --exclude=.git USER@BUILD_HOST:src/jnalib/ jnalib/

```

```bash
# Build JNA and run unittests
cd jnalib
chmod +x native/libffi/configure native/libffi/install-sh
/root/apache-ant-1.10.14/bin/ant

```

```bash
# Copy jna native library back to host system
scp lib/native/freebsd-aarch64.jar USER@BUILD_HOST:src/jnalib/lib/native

```

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

### Generating COM Bindings with TlbImp

Source: https://github.com/java-native-access/jna/blob/master/www/PlatformLibrary.md

Example command to generate JNA bindings for COM interfaces using the TlbImp tool. This is used for the first approach of COM binding.

```shell
java -cp "dist/jna.jar;dist/jna-platform.jar" com.sun.jna.platform.win32.COM.tlb.TlbImp -tlb.id {50A7E9B0-70EF-11D1-B75A-00A0C90564FE} -tlb.major.version 1 -tlb.minor.version 0 -bind.mode dispId -output.dir outputdir
```

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

### Autoreconf Not Found Error Example

Source: https://github.com/java-native-access/jna/blob/master/www/RaspberryPiDevelopmentEnvironment.md

This error message indicates that 'autoreconf' is missing, which is part of the autotools package. Install the necessary build tools to resolve this.

```bash
./autogen.sh: 2: exec: autoreconf: not found
```

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

### Build JNA for FreeBSD x86-64

Source: https://github.com/java-native-access/jna/blob/master/www/FreeBSD.md

Steps to build the JNA native library for FreeBSD x86-64. This involves setting up a FreeBSD VM, installing dependencies, and compiling the library using Ant.

```bash
# Fetch image
wget https://download.freebsd.org/releases/VM-IMAGES/13.2-RELEASE/amd64/Latest/FreeBSD-13.2-RELEASE-amd64.qcow2.xz

```

```bash
xz -d FreeBSD-13.2-RELEASE-amd64.qcow2.xz

```

```bash
# Ensure there is enough space in the image
qemu-img resize -f qcow2 FreeBSD-13.2-RELEASE-amd64.qcow2 +5G

```

```bash
# Launch image
qemu-system-amd64 -m 4096M -drive file=FreeBSD-13.2-RELEASE-amd64.qcow2

```

```bash
gpart show /dev/ada0
gpart recover /dev/ada0
gpart show /dev/ada0
gpart resize -i 4 /dev/ada0
growfs /

```

```bash
# Exit single user mode (BSD boots to multi-user)
exit

```

```bash
# Login as root

```

```bash
# Set keyboard configuration
kbdmap

```

```bash
# Set current date and time (YYYYMMDDHHMM)
date 202403081928

```

```bash
# Install prerequisites - part 1 - java, build system, rsync
pkg install openjdk17 wget automake rsync gmake gcc bash texinfo
# Adjust fstab (optional, only needed if reboot is planned)
# fdesc   /dev/fd         fdescfs         rw      0       0
# proc    /proc           procfs          rw      0       0

```

```bash
# Install prerequisites - part 2 - ant
wget https://dlcdn.apache.org/ant/binaries/apache-ant-1.10.14-bin.zip
unzip apache-ant-1.10.14-bin.zip

```

```bash
# Transfer JNA source code to build environment
rsync -av --exclude=.git USER@BUILD_HOST:src/jnalib/ jnalib/

```

```bash
# Build JNA and run unittests
cd jnalib
chmod +x native/libffi/configure native/libffi/install-sh
/root/apache-ant-1.10.14/bin/ant

```

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

### Map and Call C Standard Library printf

Source: https://github.com/java-native-access/jna/blob/master/www/GettingStarted.md

This example demonstrates mapping the C standard library's printf function and calling it from Java. Ensure jna.jar is in your CLASSPATH.

```java
package com.sun.jna.examples;

import com.sun.jna.Library;
import com.sun.jna.Native;
import com.sun.jna.Platform;

/** Simple example of JNA interface mapping and usage. */
public class HelloWorld {

    // This is the standard, stable way of mapping, which supports extensive
    // customization and mapping of Java to native types.

    public interface CLibrary extends Library {
        CLibrary INSTANCE = (CLibrary) 
            Native.load((Platform.isWindows() ? "msvcrt" : "c"), 
                                CLibrary.class);

        void printf(String format, Object... args);
    }

    public static void main(String[] args) {
        CLibrary.INSTANCE.printf("Hello, World\n");
        for (int i=0;i < args.length;i++) {
            CLibrary.INSTANCE.printf("Argument %d: %s\n", i, args[i]);
        }
    }
}
```

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

### Troubleshooting Xcode Command Line Tools Error

Source: https://github.com/java-native-access/jna/blob/master/www/MacDevelopmentEnvironment.md

Addresses build errors related to missing Xcode when only command line tools are installed. Requires installing the full Xcode application.

```bash
native:
     [exec] xcode-select: error: tool 'xcodebuild' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance
```

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

### Register Native Library for Direct Mapping

Source: https://github.com/java-native-access/jna/blob/master/www/DirectMapping.md

Register the native library using `Native.register()` within a static initializer. This example demonstrates mapping `cos` and `sin` functions from the C library.

```java
import com.sun.jna.*;

public class HelloWorld {
            
    public static native double cos(double x);
    public static native double sin(double x);
    
    static {
        Native.register(Platform.C_LIBRARY_NAME);
    }

    public static void main(String[] args) {
        System.out.println("cos(0)=" + cos(0));
        System.out.println("sin(0)=" + sin(0));
    }
}
```

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

### Set JAVA_HOME for x86_64 JDK

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Set the JAVA_HOME environment variable to point to the root of the target x86_64 JDK installation. This is required for the build process.

```cmd
set JAVA_HOME=C:\Program Files\AdoptOpenJDK\jdk-8.0.222.10-hotspot
```

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

### AIX Environment Setup for JNA Native Library Build

Source: https://github.com/java-native-access/jna/blob/master/www/BuildingNativeLibraries.md

Sets up the environment variables for building JNA native libraries on AIX, ensuring the correct make utility and ARFLAGS are used.

```bash
# Ensure `gmake` is used
export MAKE=gmake
# Place local binaries on the path
export PATH=/home/$USER/local/bin:$PATH
# Ensure working ARFLAGS are used
export ARFLAGS='-X32_64 cru'
```

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

### Add Msi Functions to Win32 Platform

Source: https://github.com/java-native-access/jna/blob/master/CHANGES.md

This snippet shows the addition of Windows Installer (MSI) functions to the platform.win32.Msi interface. These are used for querying component paths and product codes.

```java
Add to `platform.win32.Msi`: `MsiGetComponentPath`, `MsiLocateComponent`, `MsiGetProductCode`, `MsiEnumComponents`.
```

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

### Set JAVA_HOME for x86 JDK

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Set the JAVA_HOME environment variable to point to the root of the target x86 JDK installation. This is required for the build process.

```cmd
set JAVA_HOME=C:\Program Files (x86)\AdoptOpenJDK\jdk-8.0.222.10-hotspot
```

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

### Add Ant to PATH

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Add the bin directory of the Ant installation to the system's PATH environment variable. This makes the 'ant' command accessible from the command line.

```cmd
set PATH=%USERPROFILE%\apache-ant-1.9.11\bin;%PATH%
```

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

### Update Ole32#CoCreateGuid and Ole32#CLSIDFromString Signatures

Source: https://github.com/java-native-access/jna/blob/master/CHANGES.md

The signature for `com.sun.jna.platform.win32.Ole32#CoCreateGuid` changed from `(GUID.ByReference pguid)` to `(GUID pguid)`. Similarly, `com.sun.jna.platform.win32.Ole32#CLSIDFromString` changed from `(WString lpsz, CLSID.ByReference pclsid)` to `(String lpsz, CLSID.ByReference pclsid)`.

```java
com.sun.jna.platform.win32.Ole32#CoCreateGuid(GUID.ByReference pguid)
com.sun.jna.platform.win32.Ole32#CoCreateGuid(GUID pguid)
com.sun.jna.platform.win32.Ole32#CLSIDFromString(WString lpsz, CLSID.ByReference pclsid)
com.sun.jna.platform.win32.Ole32#CLSIDFromString(String lpsz, CLSID.ByReference pclsid)
```

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

### Configure libffi help

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

To view all available configuration options, run 'configure --help'.

```bash
configure --help
```

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

### Add SetupApi Functions to Win32 Platform

Source: https://github.com/java-native-access/jna/blob/master/CHANGES.md

This snippet details the integration of SetupAPI functions into the platform.win32.SetupApi interface. These are used for device information management on Windows.

```java
Add to `platform.win32.SetupApi`: `SetupDiGetClassDevs`, `SetupDiDestroyDeviceInfoList`, `SetupDiEnumDeviceInterfaces`, `SetupDiGetDeviceInterfaceDetail`, `SetupDiGetDeviceRegistryProperty`.
```

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

### Build libffi

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

After configuration, type 'make' to build the library. Ensure you are using GNU make.

```bash
make
```

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

### Get Environment Variable in JNA

Source: https://github.com/java-native-access/jna/blob/master/CHANGES.md

Use `platform.win32.Kernel32.GetEnvironmentVariable` or `platform.win32.Kernel32Util.getEnvironmentVariable` to retrieve environment variables on Windows systems.

```java
platform.win32.Kernel32.GetEnvironmentVariable
```

```java
platform.win32.Kernel32Util.getEnvironmentVariable
```

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

### Get Field Order for Structures in JNA

Source: https://github.com/java-native-access/jna/blob/master/CHANGES.md

Use `Structure.getFieldOrder()` to retrieve the correct field names for structures. This method supersedes `Structure.setFieldOrder()` and is now required.

```java
Structure.getFieldOrder()
```

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

### Build JNA Project (Unix-like)

Source: https://github.com/java-native-access/jna/blob/master/www/Contributing.md

Clone the JNA repository and build the project on most Unix-like systems.

```bash
% git clone git@github.com:java-native-access/jna
% ant dist test test-platform
```

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

### Enable Native Access for Classpath Loading (JDK 24+)

Source: https://github.com/java-native-access/jna/blob/master/src/com/sun/jna/overview.html

Use this command when JNA is loaded from the classpath to enable native access, preparing for future JDK restrictions on JNI.

```bash
java --enable-native-access=ALL-UNNAMED -jar jna.jar
```

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

### Build libffi from git sources

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

If building libffi directly from git, run ./autogen.sh first to generate the configure script. This requires autoconf, automake, and libtool.

```bash
./autogen.sh
```

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

### Set Android NDK Platform and PATH

Source: https://github.com/java-native-access/jna/blob/master/www/AndroidDevelopmentEnvironment.md

Configure environment variables for the Android NDK platform and add toolchain binaries to the system's PATH. This is necessary for the native build process.

```bash
export NDK_PLATFORM=/home/matthias/bin/android-ndk-r12b/platforms/android-21
export PATH=$NDK_PLATFORM/../../toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/bin/:$PATH
export PATH=$NDK_PLATFORM/../../toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/:$PATH
export PATH=$NDK_PLATFORM/../../toolchains/mips64el-linux-android-4.9/prebuilt/linux-x86_64/bin/:$PATH
export PATH=$NDK_PLATFORM/../../toolchains/mipsel-linux-android-4.9/prebuilt/linux-x86_64/bin/:$PATH
export PATH=$NDK_PLATFORM/../../toolchains/x86-4.9/prebuilt/linux-x86_64/bin/:$PATH
export PATH=$NDK_PLATFORM/../../toolchains/x86_64-4.9/prebuilt/linux-x86_64/bin/:$PATH
```

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

### Set JAVA_HOME for aarch64 JDK

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Set the JAVA_HOME environment variable to point to the root of the target aarch64 JDK installation. This is for native builds; for cross-compiling, use the x86_64 setting.

```cmd
set JAVA_HOME=%USERPROFILE%\jdk-16-ea+19-windows-aarch64
```

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

### Use TypeMapper for Library-Wide Custom Conversions

Source: https://context7.com/java-native-access/jna/llms.txt

Configure a TypeMapper for a library to handle custom type conversions globally. This example shows mapping Java Boolean to native Integer.

```java
public interface MyLibrary extends Library {
    TypeMapper MAPPER = new DefaultTypeMapper() {
        {
            addTypeConverter(Boolean.class, new TypeConverter() {
                public Object fromNative(Object value, FromNativeContext ctx) {
                    return ((Integer) value) != 0;
                }
                public Object toNative(Object value, ToNativeContext ctx) {
                    return ((Boolean) value) ? 1 : 0;
                }
                public Class<?> nativeType() { return Integer.class; }
            });
        }
    };

    Map<String, Object> OPTIONS = new HashMap<String, Object>() {
        {
            put(Library.OPTION_TYPE_MAPPER, MAPPER);
        }
    };

    MyLibrary INSTANCE = Native.load("mylib", MyLibrary.class, OPTIONS);

    // Boolean now maps to native int automatically
    boolean isReady();
}
```

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

### Copy JNA Native Library to Host

Source: https://github.com/java-native-access/jna/blob/master/www/FreeBSD.md

Use this command to copy the FreeBSD x86-64 JNA native library JAR file to the specified location on the build host.

```bash
scp lib/native/freebsd-x86-64.jar USER@BUILD_HOST:src/jnalib/lib/native
```

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

### Get Global Variable Address with JNA

Source: https://github.com/java-native-access/jna/blob/master/src/com/sun/jna/overview.html

Obtain the address of a global variable using NativeLibrary.getGlobalVariableAddress. The address is returned as a Pointer, which can then be used to read or write the variable's value.

```java
Pointer globalVarPtr = NativeLibrary.getGlobalVariableAddress("my_global_var");
```

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

### Compile and Run Unit Tests with Ant

Source: https://github.com/java-native-access/jna/blob/master/www/MacDevelopmentEnvironment.md

Compiles the JNA project and runs unit tests for the current architecture using the Ant build tool.

```bash
ant
```

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

### Configure libffi for 64-bit Windows with MSVC

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

For 64-bit Windows builds using MSVC, append the -m64 flag to the CC and CXX compiler commands. Ensure the --build option is set appropriately.

```bash
path/to/configure CC="path/to/msvcc.sh -m64" CXX="path/to/msvcc.sh -m64" LD=link CPP="cl -nologo -EP" CPPFLAGS="-DFFI_BUILDING_DLL"
```

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

### Build libffi static library for ARM64 with MSVC

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

Static library builds for ARM64 with MSVC are available in the msvc_build folder. Use the provided Visual Studio solution file and header files.

```bash
aarch64/Ffi_staticLib.sln
```

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

### Support Zero-Length REG_MULTI_SZ on Win32

Source: https://github.com/java-native-access/jna/blob/master/CHANGES.md

This fix enables proper support for getting and setting zero-length `REG_MULTI_SZ` values on Windows (Win32). This addresses issues with registry manipulation involving multi-string values.

```c
Properly support getting and setting zero-array-length `REG_MULTI_SZ` values on Win32.
```

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

### Enable Debug Mode in MSVC Build Script

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Toggle debug mode in the `native/libffi/msvcc.sh` script to get more verbose output for troubleshooting MSVC build issues. This helps in identifying specific compilation or linking problems.

```diff
- verbose=
+ verbose=1
```

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

### Platform Detection and File Utilities with JNA

Source: https://context7.com/java-native-access/jna/llms.txt

Detects the current operating system and its architecture, and demonstrates cross-platform file operations like moving files to the trash. Requires the jna-platform library.

```java
import com.sun.jna.Platform;
import com.sun.jna.platform.FileUtils;
import com.sun.jna.platform.FileMonitor;
import java.io.File;
import java.io.IOException;

public class PlatformUtilsExample {
    public static void main(String[] args) throws Exception {
        // Platform detection
        System.out.println("OS: " + System.getProperty("os.name"));
        System.out.println("Is Windows: " + Platform.isWindows());
        System.out.println("Is Mac: " + Platform.isMac());
        System.out.println("Is Linux: " + Platform.isLinux());
        System.out.println("Is 64-bit: " + Platform.is64Bit());
        System.out.println("C Library: " + Platform.C_LIBRARY_NAME);

        // Cross-platform file utilities
        FileUtils fileUtils = FileUtils.getInstance();

        // Check if trash is supported
        if (fileUtils.hasTrash()) {
            System.out.println("Trash supported on this platform");

            // Move file to trash instead of permanent delete
            File tempFile = File.createTempFile("test", ".txt");
            tempFile.deleteOnExit();

            // fileUtils.moveToTrash(tempFile);
            // System.out.println("Moved to trash: " + tempFile);
        }

        // File monitoring (cross-platform)
        FileMonitor monitor = FileMonitor.getInstance();
        File watchDir = new File(System.getProperty("user.home"));

        monitor.addWatch(watchDir);
        monitor.addFileListener(new FileMonitor.FileListener() {
            public void fileChanged(FileMonitor.FileEvent e) {
                System.out.println("File changed: " + e.getFile());
            }
            public void fileDeleted(FileMonitor.FileEvent e) {
                System.out.println("File deleted: " + e.getFile());
            }
            public void fileCreated(FileMonitor.FileEvent e) {
                System.out.println("File created: " + e.getFile());
            }
        });

        System.out.println("Monitoring: " + watchDir);
        Thread.sleep(5000); // Watch for 5 seconds

        monitor.removeWatch(watchDir);
        System.out.println("Stopped monitoring");
    }
}
```

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

### Build Native Package for Older JDKs (Solaris x86)

Source: https://github.com/java-native-access/jna/blob/master/CHANGES.md

Instructions for building JNA's native code package for platforms with JDK versions lower than 8. This involves using Ant with specific properties and then building on the target system.

```bash
ant -Dbuild.os.name=SunOS -Dbuild.os.arch=x86 native-build-package
```

```bash
bash build.sh
```

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

### Cross-Compile for Alternate Architectures with Ant

Source: https://github.com/java-native-access/jna/blob/master/www/MacDevelopmentEnvironment.md

Cross-compiles JNA for different macOS architectures using Ant by setting the 'os.prefix' property.

```bash
# ARM64 (>= 11.0)
ant -Dos.prefix=darwin-aarch64
```

```bash
# x86 (<= 10.13)
ant -Dos.prefix=darwin-x86
```

```bash
# x86_64
ant -Dos.prefix=darwin-x86-64
```

```bash
# PPC (<= 10.5)
ant -Dos.prefix=darwin-ppc
```

```bash
# PPC64
ant -Dos.prefix=darwin-ppc64
```

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

### Build OpenBSD x86 Native Libraries

Source: https://github.com/java-native-access/jna/blob/master/www/BuildingNativeLibraries.md

Steps to build JNA native libraries for OpenBSD x86. This involves transferring build packages, setting Java and make environments, and executing the build script.

```bash
scp user@BUILD_HOST:src/jnalib/build/build-package-openbsd-x86-7.0.2.zip . 
unzip build-package-openbsd-x86-7.0.2.zip
cd build-package-openbsd-x86-7.0.2
export JAVA_HOME=/usr/local/jdk-1.8.0
export MAKE=gmake
sh build.sh
scp openbsd-x86.jar user@BUILD_HOST:src/jnalib/lib/native
```

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

### Configure MSVC Environment Variables in Bash

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Set MSVC, WSDK, and WSDK_64 environment variables and configure INCLUDE and LIB paths for cross-compiling on Windows using bash. Ensure cygpath is used for path conversion.

```bash
export MSVC="/c/Program Files (x86)/Microsoft Visual Studio 10.0/vc"
export WSDK="/c/Program Files (x86)/Microsoft SDKs/Windows/v7.0A"
export WSDK_64="/c/Program Files/Microsoft SDKs/Windows/v7.1"

export INCLUDE="$(cygpath -m "$MSVC")/include;$(cygpath -m "$WSDK")/include"
# for x86_64 target
export LIB="$(cygpath -m "$MSVC")/lib/amd64;$(cygpath -m "$WSDK_64")/lib/x64"
# for x86 target
export LIB="$(cygpath -m "$MSVC")/lib;$(cygpath -m "$WSDK")/lib"
```

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

### Build JNA Project

Source: https://github.com/java-native-access/jna/blob/master/www/Contributing.md

Build the JNA project using Ant. This command builds the distribution, runs tests, and tests the platform-specific libraries.

```bash
ant dist test test-platform
```

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

### Compile with Alternate macOS SDK using Ant

Source: https://github.com/java-native-access/jna/blob/master/www/MacDevelopmentEnvironment.md

Specifies an older macOS SDK root for compilation when using Ant.

```bash
ant -DSDKROOT=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk
```

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

### Configure libffi for Windows with clang-cl

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

To build libffi on Windows using the LLVM clang-cl compiler, specify the -clang-cl flag for CC and CXX.

```bash
path/to/configure CC="path/to/msvcc.sh -clang-cl" CXX="path/to/msvcc.sh -clang-cl" LD=link CPP="clang-cl -EP"
```

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

### Build OpenBSD x86-64 Native Libraries

Source: https://github.com/java-native-access/jna/blob/master/www/BuildingNativeLibraries.md

Steps to build JNA native libraries for OpenBSD x86-64. This involves transferring build packages, setting Java and make environments, and executing the build script.

```bash
scp user@BUILD_HOST:src/jnalib/build/build-package-openbsd-x86-64-7.0.2.zip . 
unzip build-package-openbsd-x86-7.0.2.zip
cd build-package-openbsd-x86-7.0.2
export JAVA_HOME=/usr/local/jdk-1.8.0
export MAKE=gmake
sh build.sh
scp openbsd-x86-64.jar user@BUILD_HOST:src/jnalib/lib/native
```

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

### Run Ant Build with Detailed Output

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Execute the Ant build process with detailed output enabled using the `-DEXTRA_MAKE_OPTS="--debug=v"` flag. This provides extensive logging to help diagnose native compilation and linking errors.

```bash
ant -DEXTRA_MAKE_OPTS="--debug=v"
```

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

### Load and Synchronize Kernel32 Instance

Source: https://github.com/java-native-access/jna/blob/master/www/GettingStarted.md

Load the kernel32 library and optionally create a synchronized instance to limit native calls to one at a time. This is useful for thread safety.

```java
Kernel32 INSTANCE = (Kernel32) 
    Native.load("kernel32", Kernel32.class);
// Optional: wraps every call to the native library in a
// synchronized block, limiting native calls to one at a time
Kernel32 SYNC_INSTANCE = (Kernel32) 
    Native.synchronizedLibrary(INSTANCE);
```

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

### Build Dragonfly BSD Native Libraries

Source: https://github.com/java-native-access/jna/blob/master/www/BuildingNativeLibraries.md

Use this command to synchronize JNA source code, set execute permissions, and build native libraries on Dragonfly BSD.

```bash
rsync -av --exclude=.git USER@BUILD_HOST:src/jnalib/ jnalib/
chmod +x jnalib/native/libffi/configure jnalib/native/libffi/install-sh
cd jnalib
ant
```

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

### JNA Mapping and Usage of ByReference

Source: https://github.com/java-native-access/jna/blob/master/www/ByRefArguments.md

Demonstrates the equivalent JNA mapping for the C allocate_buffer function and its usage with PointerByReference and IntByReference to capture returned values. Ensure necessary JNA classes are imported.

```java
// Equivalent JNA mapping
void allocate_buffer(PointerByReference bufp, IntByReference lenp);

// Usage
PointerByReference pref = new PointerByReference();
IntByReference iref = new IntByReference();
lib.allocate_buffer(pref, iref);
Pointer p = pref.getValue();
byte[] buffer = p.getByteArray(0, iref.getValue());
```

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

### Enable Native Access for Modulepath Loading (JDK 24+)

Source: https://github.com/java-native-access/jna/blob/master/src/com/sun/jna/overview.html

Use this command when JNA is loaded from the modulepath to enable native access for a specific module, addressing JDK 24+ security changes.

```bash
java --enable-native-access=com.sun.jna -p jna-jpms.jar -m com.sun.jna
```

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

### Configure libffi for Windows with MSVC

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

Use the msvcc.sh wrapper script for configuring libffi on Windows with Microsoft Visual C++ compiler. Specify CC, CXX, LD, and CPP flags as shown.

```bash
path/to/configure CC=path/to/msvcc.sh CXX=path/to/msvcc.sh LD=link CPP="cl -nologo -EP" CPPFLAGS="-DFFI_BUILDING_DLL"
```

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

### Solaris x86 64-bit JNA Native Library Build

Source: https://github.com/java-native-access/jna/blob/master/www/BuildingNativeLibraries.md

Builds the 64-bit JNA native library for Solaris x86 by configuring libffi, building, and copying the resulting JAR.

```bash
# Reference the 64bit JKD 8
export JAVA_HOME=/opt/csw/java/jdk1.8.0_201
# Build
cd build-package-sunos-x86-64-7.0.2/native/libffi
bash autogen.sh
./configure
cd ../..
bash build.sh
# Copy result
cp sunos-x86-64.jar ../
cd ..
```

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

### Build JNA for Android Architectures

Source: https://github.com/java-native-access/jna/blob/master/www/AndroidDevelopmentEnvironment.md

Execute Ant build commands to compile JNA for various Android architectures. Use the '-Dos.prefix' flag to specify the target architecture.

```bash
ant -Dos.prefix=android-aarch64
```

```bash
ant -Dos.prefix=android-armv7
```

```bash
ant -Dos.prefix=android-arm
```

```bash
ant -Dos.prefix=android-mips64
```

```bash
ant -Dos.prefix=android-mips
```

```bash
ant -Dos.prefix=android-x86-64
```

```bash
ant -Dos.prefix=android-x86
```

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

### Customize dlopen Behavior with Library Options

Source: https://github.com/java-native-access/jna/blob/master/CHANGES.md

Utilize `Library.OPTION_OPEN_FLAGS` to customize the behavior of `dlopen`. This allows for fine-grained control over how native libraries are loaded.

```java
Library.OPTION_OPEN_FLAGS
```

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

### Solaris SPARC 64-bit JNA Native Library Build

Source: https://github.com/java-native-access/jna/blob/master/www/BuildingNativeLibraries.md

Builds the 64-bit JNA native library for Solaris SPARC by configuring libffi, building, and copying the resulting JAR.

```bash
# Reference the 64bit JKD 8
export JAVA_HOME=/opt/csw/java/jdk1.8.0_201
# Build
cd build-package-sunos-sparcv9-7.0.2/native/libffi
bash autogen.sh
./configure
cd ../..
bash build.sh
# Copy result
cp sunos-sparcv9.jar ../
cd ..
```

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

### Calling COM Methods with COMBindingBaseObject

Source: https://github.com/java-native-access/jna/blob/master/www/PlatformLibrary.md

Demonstrates how to call COM methods using the COMBindingBaseObject class. This approach requires manual marshalling and unmarshalling of parameters and return values.

```java
this.oleMethod(OleAuto.DISPATCH_PROPERTYPUT, result, this.iDispatch, "Visible", new VARIANT(bVisible));
```

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

### Add Cygwin to PATH

Source: https://github.com/java-native-access/jna/blob/master/www/WindowsDevelopmentEnvironment.md

Add the Cygwin 64-bit bin directory to the system's PATH environment variable. This is necessary for using Cygwin tools in the command prompt.

```cmd
set PATH=C:\cygwin64\bin\;%PATH%
```

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

### Configure libffi with Purify safety checks

Source: https://github.com/java-native-access/jna/blob/master/native/libffi/README.md

Employ the --enable-purify-safety configure switch to include extra code that suppresses warnings when using Purify. This switch should only be used when Purify is active, as it impacts performance.

```bash
./configure --enable-purify-safety
```

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

### Replace User32#MonitorFromPoint signature

Source: https://github.com/java-native-access/jna/blob/master/CHANGES.md

Replaces the signature of `com.sun.jna.platform.win32.User32#MonitorFromPoint(Point pt, int dwFlags)` with `com.sun.jna.platform.win32.User32#MonitorFromPoint(Point.ByValue pt, int dwFlags)`.

```java
com.sun.jna.platform.win32.User32#MonitorFromPoint(Point pt, int dwFlags) was replaced by com.sun.jna.platform.win32.User32#MonitorFromPoint(Point.ByValue pt, int dwFlags)
```