Using Camera API

package com.example;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.app.Activity;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.ShutterCallback;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.FrameLayout;

public class CameraDemo extends Activity {
	private static final String TAG = "CameraDemo";
	Camera camera;
	Preview preview;
	Button buttonClick;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		preview = new Preview(this);
		((FrameLayout) findViewById(R.id.preview)).addView(preview);

		buttonClick = (Button) findViewById(R.id.buttonClick);
		buttonClick.setOnClickListener(new OnClickListener() {
			public void onClick(View v) {
				preview.camera.takePicture(shutterCallback, rawCallback,
						jpegCallback);
			}
		});

		Log.d(TAG, "onCreate'd");
	}

	ShutterCallback shutterCallback = new ShutterCallback() {
		public void onShutter() {
			Log.d(TAG, "onShutter'd");
		}
	};

	/** Handles data for raw picture */
	PictureCallback rawCallback = new PictureCallback() {
		public void onPictureTaken(byte[] data, Camera camera) {
			Log.d(TAG, "onPictureTaken - raw");
		}
	};

	/** Handles data for jpeg picture */
	PictureCallback jpegCallback = new PictureCallback() {
		public void onPictureTaken(byte[] data, Camera camera) {
			FileOutputStream outStream = null;
			try {
				// write to local sandbox file system
				// outStream =
				// CameraDemo.this.openFileOutput(String.format("%d.jpg",
				// System.currentTimeMillis()), 0);
				// Or write to sdcard
				outStream = new FileOutputStream(String.format(
						"/sdcard/%d.jpg", System.currentTimeMillis()));
				outStream.write(data);
				outStream.close();
				Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length);
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			} finally {
			}
			Log.d(TAG, "onPictureTaken - jpeg");
		}
	};

}

package com.example;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.hardware.Camera;
import android.hardware.Camera.PreviewCallback;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

class Preview extends SurfaceView implements SurfaceHolder.Callback {
	private static final String TAG = "Preview";

	SurfaceHolder mHolder;
	public Camera camera;

	Preview(Context context) {
		super(context);

		// Install a SurfaceHolder.Callback so we get notified when the
		// underlying surface is created and destroyed.
		mHolder = getHolder();
		mHolder.addCallback(this);
		mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
	}

	public void surfaceCreated(SurfaceHolder holder) {
		// The Surface has been created, acquire the camera and tell it where
		// to draw.
		camera = Camera.open();
		try {
			camera.setPreviewDisplay(holder);

			camera.setPreviewCallback(new PreviewCallback() {

				public void onPreviewFrame(byte[] data, Camera arg1) {
					FileOutputStream outStream = null;
					try {
						outStream = new FileOutputStream(String.format(
								"/sdcard/%d.jpg", System.currentTimeMillis()));
						outStream.write(data);
						outStream.close();
						Log.d(TAG, "onPreviewFrame - wrote bytes: "
								+ data.length);
					} catch (FileNotFoundException e) {
						e.printStackTrace();
					} catch (IOException e) {
						e.printStackTrace();
					} finally {
					}
					Preview.this.invalidate();
				}
			});
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public void surfaceDestroyed(SurfaceHolder holder) {
		// Surface will be destroyed when we return, so stop the preview.
		// Because the CameraDevice object is not a shared resource, it's very
		// important to release it when the activity is paused.
		camera.stopPreview();
		camera = null;
	}

	public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
		// Now that the size is known, set up the camera parameters and begin
		// the preview.
		Camera.Parameters parameters = camera.getParameters();
		parameters.setPreviewSize(w, h);
		camera.setParameters(parameters);
		camera.startPreview();
	}

	@Override
	public void draw(Canvas canvas) {
		super.draw(canvas);
		Paint p = new Paint(Color.RED);
		Log.d(TAG, "draw");
		canvas.drawText("PREVIEW", canvas.getWidth() / 2,
				canvas.getHeight() / 2, p);
	}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="fill_parent"
	android:layout_height="fill_parent" android:id="@+id/layout">
	<TextView android:layout_width="fill_parent"
		android:layout_height="wrap_content" android:text="Camera Demo"
		android:textSize="24sp" />

	<FrameLayout android:id="@+id/preview"
		android:layout_weight="1" android:layout_width="fill_parent"
		android:layout_height="fill_parent">
	</FrameLayout>

	<Button android:layout_width="wrap_content"
		android:layout_height="wrap_content" android:id="@+id/buttonClick"
		android:text="Click" android:layout_gravity="center"></Button>

</LinearLayout>