写一个可以拍摄raw图并可以获取预览流的raw图的camera app，包括xml

好的，以下是一个可以拍摄raw图并可以获取预览流的camera app的代码和相应的xml文件。

首先是MainActivity.java文件的代码：

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.camera.core.Camera;
import androidx.camera.core.CameraSelector;
import androidx.camera.core.CameraX;
import androidx.camera.core.ImageAnalysis;
import androidx.camera.core.ImageCapture;
import androidx.camera.core.ImageCaptureException;
import androidx.camera.core.ImageProxy;
import androidx.camera.core.Preview;
import androidx.camera.lifecycle.ProcessCameraProvider;
import androidx.camera.view.PreviewView;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.lifecycle.LifecycleOwner;

import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.media.Image;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.util.Size;
import android.view.Surface;
import android.view.TextureView;
import android.widget.Button;
import android.widget.Toast;

import com.google.common.util.concurrent.ListenableFuture;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.nio.ByteBuffer;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "CameraX";
    private static final int REQUEST_CODE_PERMISSIONS = 10;
    private static final String[] REQUIRED_PERMISSIONS = new String[]{Manifest.permission.CAMERA};
    private PreviewView previewView;
    private ListenableFuture<ProcessCameraProvider> cameraProviderFuture;
    private Executor executor = Executors.newSingleThreadExecutor();
    private ImageCapture imageCapture;
    private Button captureButton;

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

        previewView = findViewById(R.id.previewView);
        captureButton = findViewById(R.id.captureButton);

        if(allPermissionsGranted()) {
            startCamera();
        } else {
            ActivityCompat.requestPermissions(this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS);
        }

        captureButton.setOnClickListener(v -> {
            takePhoto();
        });
    }

    private boolean allPermissionsGranted() {
        for(String permission : REQUIRED_PERMISSIONS) {
            if(ContextCompat.checkSelfPermission(this, permission) != PackageManager.PERMISSION_GRANTED) {
                return false;
            }
        }
        return true;
    }

    private void startCamera() {
        cameraProviderFuture = ProcessCameraProvider.getInstance(this);
        cameraProviderFuture.addListener(() -> {
            try {
                ProcessCameraProvider cameraProvider = cameraProviderFuture.get();
                bindPreview(cameraProvider);
            } catch (ExecutionException | InterruptedException e) {
                Log.e(TAG, "Error starting camera", e);
            }
        }, ContextCompat.getMainExecutor(this));
    }

    private void bindPreview(@NonNull ProcessCameraProvider cameraProvider) {
        Preview preview = new Preview.Builder()
                .build();

        CameraSelector cameraSelector = new CameraSelector.Builder()
                .requireLensFacing(CameraSelector.LENS_FACING_BACK)
                .build();

        preview.setSurfaceProvider(previewView.createSurfaceProvider());

        ImageAnalysis imageAnalysis =
                new ImageAnalysis.Builder()
                        .setTargetResolution(new Size(1280, 720))
                        .setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
                        .build();

        imageAnalysis.setAnalyzer(executor, new ImageAnalysis.Analyzer() {
            @RequiresApi(api = Build.VERSION_CODES.KITKAT)
            @Override
            public void analyze(@NonNull ImageProxy image) {
                Log.d(TAG, "Analysis called");
                ByteBuffer buffer = image.getPlanes()[0].getBuffer();
                byte[] bytes = new byte[buffer.capacity()];
                buffer.get(bytes);
                saveRawImage(bytes);
            }
        });

        imageCapture = new ImageCapture.Builder()
                .setCaptureMode(ImageCapture.CAPTURE_MODE_MINIMIZE_LATENCY)
                .build();

        cameraProvider.unbindAll();

        Camera camera = cameraProvider.bindToLifecycle((LifecycleOwner)this, cameraSelector, preview, imageAnalysis, imageCapture);
    }

    private void takePhoto() {
        SimpleDateFormat mDateFormat = new SimpleDateFormat("yyyyMMddHHmmss", java.util.Locale.getDefault());
        File file = new File(getBatchDirectoryName(), mDateFormat.format(new Date())+ ".raw");
        ImageCapture.OutputFileOptions outputFileOptions = new ImageCapture.OutputFileOptions.Builder(file).build();
        imageCapture.takePicture(outputFileOptions, executor, new ImageCapture.OnImageSavedCallback() {
            @Override
            public void onImageSaved(@NonNull ImageCapture.OutputFileResults outputFileResults) {
                runOnUiThread(() -> {
                    Toast.makeText(MainActivity.this, "Image saved successfully", Toast.LENGTH_SHORT).show();
                });
            }

            @Override
            public void onError(@NonNull ImageCaptureException error) {
                Log.e(TAG, "Error capturing image", error);
            }
        });
    }

    private File getBatchDirectoryName() {
        File file = new File(getExternalFilesDir(null), "RawImages");
        if (!file.exists()) {
            file.mkdirs();
        }
        return file;
    }

    private void saveRawImage(byte[] bytes) {
        File file = new File(getBatchDirectoryName(), "preview.jpg");
        Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
        Matrix matrix = new Matrix();
        matrix.postRotate(90);
        Bitmap rotatedBitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        rotatedBitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
        byte[] byteArray = stream.toByteArray();
        try {
            FileOutputStream fos = new FileOutputStream(file);
            fos.write(byteArray);
            fos.close();
        } catch (java.io.IOException e) {
            Log.e(TAG, "Error saving preview image", e);
        }
    }
}

接下来是activity_main.xml文件的代码：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.camera.view.PreviewView
        android:id="@+id/previewView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintBottom_toTopOf="@id/captureButton"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <Button
        android:id="@+id/captureButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Capture"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

这个camera app可以在Android设备上拍摄raw图并获取预览流。在拍摄照片时，它会将照片保存到设备上，并在屏幕上显示一个Toast消息。同时，它还会将预览流转换成JPEG格式并保存到设备上，以供用户预览。