安卓开发调用安卓手机系统的人脸识别功能，当识别成功时实现页面跳转，完整代码怎么实现？

首先，你需要在 AndroidManifest.xml 文件中添加以下权限：

<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />

然后，在你想要调用人脸识别功能的 Activity 中，添加以下代码：

// 导入人脸识别相关的类
import android.hardware.Camera;
import android.hardware.Camera.Face;
import android.hardware.Camera.FaceDetectionListener;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity implements SurfaceHolder.Callback, FaceDetectionListener {
    private SurfaceView mSurfaceView;    // 预览窗口
    private SurfaceHolder mSurfaceHolder;
    private Camera mCamera;
    private Button mButton;
    private boolean isPreviewing;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
        mSurfaceHolder = mSurfaceView.getHolder();
        mSurfaceHolder.addCallback(this);
        
        mButton = (Button) findViewById(R.id.button);
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                takePicture();
            }
        });
    }

    // SurfaceHolder.Callback 接口的实现
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        mCamera = Camera.open();
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        if (isPreviewing) {
            mCamera.stopFaceDetection();
            mCamera.stopPreview();
            isPreviewing = false;
        }

        try {
            mCamera.setPreviewDisplay(holder);
            mCamera.startPreview();
            mCamera.startFaceDetection();
            isPreviewing = true;
        } catch (Exception e) {
            Log.e("MainActivity", e.getMessage());
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        mCamera.stopFaceDetection();
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
        isPreviewing = false;
    }

    // FaceDetectionListener 接口的实现
    @Override
    public void onFaceDetection(Face[] faces, Camera camera) {
        if (faces.length > 0) {
            Toast.makeText(this, "识别到人脸！", Toast.LENGTH_SHORT).show();
            // 这里可以进行页面跳转等操作
        }
    }

    private void takePicture() {
        if (mCamera != null) {
            mCamera.takePicture(null, null, null, new Camera.PictureCallback() {
                @Override
                public void onPictureTaken(byte[] data, Camera camera) {
                    Intent intent = new Intent(MainActivity.this, ResultActivity.class);
                    intent.putExtra("picture_data", data);
                    startActivity(intent);
                }
            });
        }
    }
}

这段代码实现了在一个 SurfaceView 上显示摄像头预览，并且在人脸被识别时弹出 Toast 提示。你可以在 onFaceDetection() 方法中添加自己的代码，实现页面跳转等操作。

注意：这段代码只是一个示例，实际开发中可能需要进行适当的修改和完善。