### Example Printed Output

Source: https://docs.sunmi.com/en-US/cdixeghjk491/xmafeghjk535

The expected text output generated by the printText method.

```plaintext
Hello Sunmi!
```

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

### Development Workflow Overview

Source: https://docs.sunmi.com/en-US/cdixeghjk491/xmafeghjk535

Visual representation of the application lifecycle from device request to release.

```plaintext
[ Request Test Device ] ──> [ Register Partner Platform ] ──> [ Apply for Developer Status ]
                                                                        │
                                                                        ▼
[ App Deployment/Release ] <── [ Integration & Debugging ] <── [ Access Hardware Capabilities ]
```

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

### Configure Module-level build.gradle

Source: https://docs.sunmi.com/en-US/cdixeghjk491/xzcxeghjk491

Define the SDK versions and include the required biometric and appcompat dependencies.

```gradle
android {
    compileSdkVersion 34
    defaultConfig {
        minSdkVersion 23  // Minimum system version
        targetSdkVersion 34
    }
}

dependencies {
    // Core dependency
    implementation 'androidx.biometric:biometric:1.1.0'
    implementation 'androidx.appcompat:appcompat:1.6.1'
}
```

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

### Implement Biometric Authentication in Java

Source: https://docs.sunmi.com/en-US/cdixeghjk491/xzcxeghjk491

A complete Activity implementation using BiometricPrompt to handle fingerprint verification, including hardware checks and callback management.

```java
import android.os.Bundle;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import androidx.biometric.BiometricManager;
import androidx.biometric.BiometricPrompt;
import androidx.core.content.ContextCompat;
import java.util.concurrent.Executor;

public class SunmiBiometricActivity extends AppCompatActivity {

    private BiometricPrompt biometricPrompt;
    private BiometricPrompt.PromptInfo promptInfo;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sunmi_biometric);

        // 1. Request permission
        requestBiometricPermission(this);
        // 2. Initialize biometrics
        initBiometric();
        // 3. Bind button to trigger verification
        findViewById(R.id.btn_verify).setOnClickListener(v -> startBiometricVerify());
    }

    /**
     * Initialize biometric components
     */
    private void initBiometric() {
        Executor executor = ContextCompat.getMainExecutor(this);
        // Build verification callback
        biometricPrompt = new BiometricPrompt(this, executor, new BiometricPrompt.AuthenticationCallback() {
            @Override
            public void onAuthenticationSucceeded(BiometricPrompt.AuthenticationResult result) {
                super.onAuthenticationSucceeded(result);
                runOnUiThread(() -> {
                    Toast.makeText(SunmiBiometricActivity.this, "Verification succeeded, execute business logic", Toast.LENGTH_SHORT).show();
                    // TODO: Integrate checkout/login/payment and other business logic
                });
            }

            @Override
            public void onAuthenticationFailed() {
                super.onAuthenticationFailed();
                runOnUiThread(() -> Toast.makeText(SunmiBiometricActivity.this, "Fingerprint mismatch, please try again", Toast.LENGTH_SHORT).show());
            }

            @Override
            public void onAuthenticationError(int errorCode, CharSequence errString) {
                super.onAuthenticationError(errorCode, errString);
                runOnUiThread(() -> Toast.makeText(SunmiBiometricActivity.this, "Verification error: " + errString, Toast.LENGTH_LONG).show());
            }
        });

        // Build verification dialog
        promptInfo = new BiometricPrompt.PromptInfo.Builder()
                .setTitle("Fingerprint Verification")
                .setSubtitle("Place finger to complete checkout/authorization")
                .setNegativeButtonText("Cancel")
                .setAllowedAuthenticators(BiometricManager.Authenticators.BIOMETRIC_STRONG) // Strong security mode
                .build();
    }

    /**
     * Start fingerprint verification (pre-check device compatibility)
     */
    private void startBiometricVerify() {
        BiometricManager biometricManager = BiometricManager.from(this);
        switch (biometricManager.canAuthenticate(BiometricManager.Authenticators.BIOMETRIC_STRONG)) {
            case BiometricManager.BIOMETRIC_SUCCESS:
                biometricPrompt.authenticate(promptInfo);
                break;
            case BiometricManager.BIOMETRIC_ERROR_NO_HARDWARE:
                Toast.makeText(this, "No fingerprint hardware on device", Toast.LENGTH_LONG).show();
                break;
            case BiometricManager.BIOMETRIC_ERROR_NONE_ENROLLED:
                Toast.makeText(this, "No fingerprint enrolled, please add in Settings", Toast.LENGTH_LONG).show();
                break;
            default:
                Toast.makeText(this, "Fingerprint function unavailable", Toast.LENGTH_LONG).show();
        }
    }

    // Dynamic permission request method (same as 2.3)
    private void requestBiometricPermission(Context context) {
        // ... Copy code from 2.3 ...
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        // ... Copy code from 2.3 ...
    }
}
```

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

### Implement Plain Text Printing in Android Activity

Source: https://docs.sunmi.com/en-US/cdixeghjk491/xmafeghjk535

Demonstrates how to retrieve the printer service from the application instance and invoke the printText method with null-safety checks.

```java
package com.sm.sdk.demo;

import android.os.Bundle;
import android.util.Log;
import androidx.appcompat.app.AppCompatActivity;
import com.sunmi.peripheral.printer.SunmiPrinterService;

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "SunmiDebug";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Execute test print
        executeTextPrint("Hello SUNMI!\n");
    }

    private void executeTextPrint(String text) {
        SunmiPrinterService printerService = MyApplication.getInstance().getSunmiPrinterService();
        
        if (printerService != null) {
            try {
                // Invoke print interface. Pass null to the second argument to use default styling callbacks.
                printerService.printText(text, null);
            } catch (Exception e) {
                Log.e(TAG, "Failed to send print command.", e);
            }
        } else {
            Log.w(TAG, "SUNMI Printer Service is unavailable. Verify service binding state and hardware compatibility.");
        }
    }
}
```

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

### Add SUNMI Printer SDK Dependency

Source: https://docs.sunmi.com/en-US/cdixeghjk491/xmafeghjk535

Include the core SUNMI printer library in the module-level build.gradle file.

```groovy
dependencies {
    // Core SUNMI Printer SDK
    implementation 'com.sunmi:printerlibrary:1.0.23'
}
```

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

### Implement Dynamic Permission Request

Source: https://docs.sunmi.com/en-US/cdixeghjk491/xzcxeghjk491

Handle runtime permission checks and result callbacks for Android 10+ compatibility.

```java
private static final int REQUEST_BIOMETRIC_PERMISSION = 1001;

// Request permission
private void requestBiometricPermission(Context context) {
    if (ContextCompat.checkSelfPermission(context, Manifest.permission.USE_BIOMETRIC)
            != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions((Activity) context,
                new String[]{Manifest.permission.USE_BIOMETRIC},
                REQUEST_BIOMETRIC_PERMISSION);
    }
}

// Permission callback
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode <mark> REQUEST_BIOMETRIC_PERMISSION) {
        if (grantResults.length </mark> 0 || grantResults[0] != PackageManager.PERMISSION_GRANTED) {
            Toast.makeText(this, "Fingerprint permission not enabled, function unavailable", Toast.LENGTH_LONG).show();
        }
    }
}
```

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

### Bind SUNMI Printer Service

Source: https://docs.sunmi.com/en-US/cdixeghjk491/xmafeghjk535

Implement asynchronous binding to the SunmiPrinterService within a custom Application class to handle hardware interactions.

```java
package com.sm.sdk.demo;

import android.app.Application;
import android.content.Context;
import com.sunmi.peripheral.printer.InnerPrinterCallback;
import com.sunmi.peripheral.printer.InnerPrinterException;
import com.sunmi.peripheral.printer.InnerPrinterManager;
import com.sunmi.peripheral.printer.SunmiPrinterService;

public class MyApplication extends Application {
    private static MyApplication instance;
    private SunmiPrinterService sunmiPrinterService;

    public static MyApplication getInstance() {
        return instance;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        instance = this;
        bindPrintService(this);
    }

    /**
     * Binds to the built-in SUNMI printer service asynchronously.
     */
    private void bindPrintService(Context context) {
        try {
            InnerPrinterManager.getInstance().bindService(context, new InnerPrinterCallback() {
                @Override
                protected void onConnected(SunmiPrinterService service) {
                    sunmiPrinterService = service;
                }

                @Override
                protected void onDisconnected() {
                    sunmiPrinterService = null;
                }
            });
        } catch (InnerPrinterException e) {
            e.printStackTrace();
        }
    }

    /**
     * Returns the active printer service instance.
     * @return SunmiPrinterService instance, or null if the service is not ready.
     */
    public SunmiPrinterService getSunmiPrinterService() {
        return sunmiPrinterService;
    }
}
```

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

### Configure AndroidManifest.xml Permissions

Source: https://docs.sunmi.com/en-US/cdixeghjk491/xzcxeghjk491

Declare biometric permissions and hardware features. Setting required to false for hardware features prevents device filtering in the Play Store.

```xml
<!-- Core biometric permission -->
<uses-permission android:name="android.permission.USE_BIOMETRIC" />
<!-- Compatible with legacy systems (optional) -->
<uses-permission android:name="android.permission.USE_FINGERPRINT" />

<!-- Declare hardware support (not mandatory, avoid device filtering) -->
<uses-feature
    android:name="android.hardware.fingerprint"
    android:required="false" />
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.