synchronized(this)与synchronized(class) 简单实例

快来打我* 2022-06-10 12:21 175阅读 0赞

参考：[http://www.cnblogs.com/highriver/archive/2011/12/18/2291965.html][http_www.cnblogs.com_highriver_archive_2011_12_18_2291965.html]

通过对以上文章的拜读，我进一步加深了对线程同步锁的理解。

下面就根据自己的理解，进行的简单实例操作演示。

在看下面的代码前，强烈建议先拜读上面的文章。

源码下载：[http://download.csdn.net/detail/yang\_hui1986527/4423728][http_download.csdn.net_detail_yang_hui1986527_4423728]

MainActivity.java

package com.snowdream.demo;
    
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.os.Handler;
    import android.os.Message;
    import android.text.TextUtils;
    import android.util.Log;
    import android.view.Menu;
    import android.view.View;
    import android.widget.TextView;
    
    public class MainActivity extends Activity {
    
    	private static final int MSG_CLEAR = 0;
    	private static final int MSG_UPDATE = 1;
    
    	private final Object mObject = new Object();
    	private final String tag = "MainActivity";
    	ExecutorService pool = null; 
    
    	private static TextView mTextView = null;
    
    	private static Handler mHandler = new Handler(){
    		public void handleMessage(Message msg){
    			switch (msg.what) {
    			case MSG_CLEAR:
    				mTextView.setText("");
    				break;
    			case MSG_UPDATE:
    				String str = (String)msg.obj;
    				if (!TextUtils.isEmpty(str)) {
    					mTextView.append(str);
    					mTextView.append("\n");
    				}
    				break;
    			default:
    				break;
    			}
    		};
    	};
    
    
    	@Override
    	public void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
    		initView();
    		initData();
    	}
    
    
    	private void initView() {
    		mTextView = (TextView)findViewById(R.id.textView1);
    	}
    
    	private void initData() {
    		pool = Executors.newFixedThreadPool(2); 
    	}
    
    
    	@Override
    	protected void onDestroy() {
    		super.onDestroy();
    		pool.shutdown();
    	}
    
    	public void OnButton1Click(View view) {
    		int id = view.getId();
    		switch (id) {
    		case R.id.button1:
    			//synchronized(class)
    			//synchronized(this)
    			mHandler.sendMessage(mHandler.obtainMessage(MSG_CLEAR));
    			
    			Sync1_Class sync1_Class = new Sync1_Class();
    			Sync1_Object sync1_Object = new Sync1_Object();
    			pool.execute(sync1_Class);
    			pool.execute(sync1_Object);
    			break;
    		case R.id.button2:
    			//synchronized(this)
    			//synchronized(this)
    			mHandler.sendMessage(mHandler.obtainMessage(MSG_CLEAR));
    			
    			Sync2_Object_1  sync2_Object_1 = new Sync2_Object_1();
    			Sync2_Object_2 sync2_Object_2 = new Sync2_Object_2();
    			pool.execute(sync2_Object_1);
    			pool.execute(sync2_Object_2);	
    			break;
    		case R.id.button3:
    			//synchronized(class)
    			//synchronized(class)
    			mHandler.sendMessage(mHandler.obtainMessage(MSG_CLEAR));
    
    			Sync3_Class_1 sync3_Class_1 = new Sync3_Class_1();
    			Sync3_Class_2 sync3_Class_2 = new Sync3_Class_2();
    			pool.execute(sync3_Class_1);
    			pool.execute(sync3_Class_2);
    			break;
    		default:
    			break;
    		}
    	}
    
    	public class Sync1_Class implements Runnable {
    		public void run() {
    			synchronized(MainActivity.class){
    				for (int i = 0; i < 100; i++) {
    					Log.i(tag, "Sync1_Class: "+ i);
    					
    					mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE, "Sync1_Class: "+ i));
    				}
    			}	
    		}
    	} 
    
    
    	public class Sync1_Object implements Runnable {
    		public void run() {
    			synchronized(mObject){
    				for (int i = 0; i < 100; i++) {
    					Log.i(tag, "Sync1_Object: "+ i);
    					
    					mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE,  "Sync1_Object: "+ i));
    				}
    			}
    		}
    	} 
    
    
    
    	public class Sync2_Object_1 implements Runnable {
    		public void run() {
    			synchronized(mObject){
    				for (int i = 0; i < 100; i++) {
    					Log.i(tag, "Sync2_Object_1: "+ i);
    					
    					mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE,  "Sync2_Object_1: "+ i));
    				}
    			}
    		}
    	} 
    
    
    	public class Sync2_Object_2 implements Runnable {
    		public void run() {
    			synchronized(mObject){
    				for (int i = 0; i < 100; i++) {
    					Log.i(tag, "Sync2_Object_2: "+ i);
    					
    					mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE,  "Sync2_Object_2: "+ i));
    				}
    			}
    		}
    	} 
    
    
    	public class Sync3_Class_1 implements Runnable {
    		public void run() {
    			synchronized(MainActivity.class){
    				for (int i = 0; i < 100; i++) {
    					Log.i(tag, "Sync3_Class_1: "+ i);
    					
    					mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE,  "Sync3_Class_1: "+ i));
    				}
    			}
    		}
    	} 
    
    
    	public class Sync3_Class_2 implements Runnable {
    		public void run() {
    			synchronized(MainActivity.class){
    				for (int i = 0; i < 100; i++) {
    					Log.i(tag, "Sync3_Class_2: "+ i);
    					
    					mHandler.sendMessage(mHandler.obtainMessage(MSG_UPDATE,  "Sync3_Class_2: "+ i));
    				}
    			}
    		}
    	} 
    
    	@Override
    	public boolean onCreateOptionsMenu(Menu menu) {
    		getMenuInflater().inflate(R.menu.activity_main, menu);
    		return true;
    	}
    }

activity\_main.xml

效果预览：

![1342020332_6955.png][]

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[http_www.cnblogs.com_highriver_archive_2011_12_18_2291965.html]: http://www.cnblogs.com/highriver/archive/2011/12/18/2291965.html
[http_download.csdn.net_detail_yang_hui1986527_4423728]: http://download.csdn.net/detail/yang_hui1986527/4423728
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