Utiliser la camera dans vos applications android

import android.app.Activity;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;
import java.io.IOException;
 
public class Preview extends SurfaceView implements SurfaceHolder.Callback{
    //création de  mes objets mHolder et mCamera
     SurfaceHolder mHolder;
    Camera mCamera;
}

Preview(Context context) {
        super(context);
 
        // Installe le SurfaceHolder.Callback pour prevenir quand la surface et créer ou détruite
        mHolder = getHolder();
        mHolder.addCallback(this);
       //type de la ssurface
       mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

public void surfaceCreated(SurfaceHolder holder) {
        //ouverture de ma camera
        mCamera = Camera.open();
        try {
           mCamera.setPreviewDisplay(holder);
        } catch (IOException exception) {
            mCamera.release();
            mCamera = null;
 
        }
    }
 
    public void surfaceDestroyed(SurfaceHolder holder) {
        //arret de ma camera quand
        mCamera.stopPreview();
        mCamera = null;
    }
 
    public void surfaceDestroyed(SurfaceHolder holder, int format, int w, int h) {
         Camera.Parameters parameters = mCamera.getParameters();
        parameters.setPreviewSize(w, h);
        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }

package org.com.afCamerasimple;
import android.app.Activity;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;
import java.io.IOException;
 
public class Preview extends SurfaceView implements SurfaceHolder.Callback{
	SurfaceHolder mHolder;
    Camera mCamera;
 
    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.
        mCamera = Camera.open();
        try {
           mCamera.setPreviewDisplay(holder);
        } catch (IOException exception) {
            mCamera.release();
            mCamera = null;
            // TODO: add more exception handling logic here
        }
    }
 
    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.
        mCamera.stopPreview();
        mCamera = null;
    }
 
    public void surfaceDestroyed(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 = mCamera.getParameters();
        parameters.setPreviewSize(w, h);
        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }
}

public class AFCameraSimple extends Activity {
	 private Preview mPreview;
 
	    @Override
		protected void onCreate(Bundle savedInstanceState) {
	        super.onCreate(savedInstanceState);
 
	        // Hide the window title.
	        requestWindowFeature(Window.FEATURE_NO_TITLE);
 
	        // Create our Preview view and set it as the content of our activity.
	        mPreview = new Preview(this);
	        setContentView(mPreview);
	    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="org.com.afCamerasimple"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".AFCameraSimple"
        android:screenOrientation="landscape"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-sdk android:minSdkVersion="3" />
     <uses-permission android:name="android.permission.CAMERA" />
</manifest>