synchronized public void methidA(){
		for(int i = 0; i< 100;i++){
			System.out.println("methidA");	
			try{
				Thread.sleep(5);	
			}catch(Exception e){
			}	
			
		}
	}

	public  void methidB(){
		synchronized(this){
			for(int i = 0; i< 100;i++){
			System.out.println("methidB");			
			try{
				Thread.sleep(5);	
			}catch(Exception e){
			}	
		}
		}
	}

僅僅是 相同效果的 兩種不同寫法 
 

public class MyObject{
	/*synchronized*/ public static void methidA(){
		for(int i = 0; i< 100;i++){
			System.out.println("methidA");	
			try{
				Thread.sleep(5);	
			}catch(Exception e){
			}	
			
		}
	}

	/*synchronized*/ public static void methidB(){
		for(int i = 0; i< 100;i++){
			System.out.println("methidB");			
			try{
				Thread.sleep(5);	
			}catch(Exception e){
			}	
		}
	}


	public static void main(String []args){
		System.out.println("test Start!");
		
		new Thread(new Runnable(){
			public void run(){
				methidA();
			}
		}).start();

		new Thread(new Runnable(){
			public void run(){
				methidB();
			}
		}).start();


	}
}


 

結果為亂序。

若將 註釋去除 ， 先列印A後B

public class MyObject{
	/*synchronized*/ public void methidA(){
		for(int i = 0; i< 100;i++){
			System.out.println("methidA");	
			try{
				Thread.sleep(5);	
			}catch(Exception e){
			}	
			
		}
	}

	/*synchronized*/ public  void methidB(){
		for(int i = 0; i< 100;i++){
			System.out.println("methidB");			
			try{
				Thread.sleep(5);	
			}catch(Exception e){
			}	
		}
	}


	public static void main(String []args){
		System.out.println("test Start!");

		MyObject obj = new MyObject();
		
		new Thread(new Runnable(){
			public void run(){
				obj.methidA();
			}
		}).start();

		new Thread(new Runnable(){
			public void run(){
				obj.methidB();
			}
		}).start();

	}
}


 

此處程式碼與上片程式碼執行相同