使用synchronized实现进程同步无效，能否帮忙解决下，谢谢！

Question

package asmTest;public class TongOne extends Thread
{
    private String cha;
    
    static Object printer = new Object();
    
    public TongOne(String cha)
    {
        this.cha = cha;
    }
    
    void print()
    {
        for (int i = 1; i <= 3; i++)
            System.out.print(cha + " ");
        
    }
    
    public void run()
    {
        synchronized (printer)
        {
            for (int i = 1; i < 3; i++)
            {
                print();
                System.out.println();
                
            }
        }
        
    }
    
    public static void main(String args[])
    {
        
        TongOne test1 = new TongOne("线程A");
        TongOne test2 = new TongOne("线程B");
        TongOne test3 = new TongOne("线程C");
        
        test1.start();
        test2.start();
        test3.start();
        
    }
}不知道是不是你想要的结果

Answer 1

package number;public class TongOne extends Thread{                     
private String cha;                                     
static Object printer = new Object();                   
public TongOne(String cha){                             
this.cha = cha;                                     
}                                                       
void print(){                  
synchronized(printer){                               
for(int i =1; i <=3;i++)                             
System.out.print(cha+ " ");                       
}                                                   
}                                                        
public void run(){                                       
                                                     
for(int i =1;i <3;i++){                               
print();                                           
System.out.println();                               
                                                   
}                                                   
                                                     
                                                     
}                                                  
public static void main(String args[]){                 
                                                     
TongOne test1 = new TongOne("线程A");                 
TongOne test2 = new TongOne("线程B");                 
TongOne test3 = new TongOne("线程C");                 
                                                     
   
try {
test1.start();       
test1.join();
test2.start(); 
test2.join();
test3.start();  
} catch (InterruptedException e) {
}                                                  
}                                                     
}                         这样就可以了
你运行下就好了   

Answer 2

public class TongOne extends Thread {
private String cha;
static Object printer = new Object(); public TongOne(String cha) {
this.cha = cha;
} void print() {
synchronized (printer) {
for (int i = 1; i <= 3; i++)
System.out.print(cha + " ");
}
} public void run() { for (int i = 1; i < 3; i++) {
print();
System.out.println(); } } public static void main(String args[]) { TongOne test1 = new TongOne("线程A");
TongOne test2 = new TongOne("线程B");
TongOne test3 = new TongOne("线程C");
try {
test1.start();
test1.join();
test2.start();
test2.join();
test3.start(); } catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} }
}

Answer 3

    存在的问题就是run方法里面调用Print（）方法后有一条输出语句。因为同步块是在Print方法里面的，一旦执行完毕后去执行输出语句的时候，该线程就释放了该资源的锁，其他等待的线程就可以去访问该资源了。

Answer 4

package asmTest;public class TongOne extends Thread
{
    private String cha;
    
    static Object printer = new Object(); 
    
    public TongOne(String cha)
    {
        this.cha = cha;
    }
    
    void print()
    {
        for (int i = 1; i <= 3; i++)
            System.out.print(cha + " ");
        
    }
    
    public void run()
    {
        synchronized (printer)        {
            for (int i = 1; i < 3; i++)
            {
                print();
                System.out.println();
                
            }
        }
        
    }
    
    public static void main(String args[])
    {
        
        TongOne test1 = new TongOne("线程A");
        TongOne test2 = new TongOne("线程B");
        TongOne test3 = new TongOne("线程C");
        
        test1.start();
        test2.start();
        test3.start();
        
    }
}static Object printer = new Object();
synchronized (printer)//这两句里printer的意义是什么，
若不用printer，又有什么可代替的呢？

Answer 5

lz 在方法块中加入了 synchronized进行同步。并对此做了同一时只能有一个线程操作它的方法。
public final void join()
                throws InterruptedException等待该线程终止。 

Answer 6

整个run()才是一个操作，所以应该给run()方法加锁
public class TongOne extends Thread{                      
private String cha;                                      
static Object printer = new Object();                    
public TongOne(String cha){                              
this.cha = cha;                                      
}                                                        
void print(){                                                                          
for(int i =1; i <=3;i++)                              
System.out.print（cha+ " ");                                                                           
}                                                         
public void run(){                                        
synchronized(printer){                                                
for(int i =1;i <3;i++){                                
print();                                            
System.out.println();                                
}                                                  
}                                                    
                                                      
                                                      
}                                                   
public static void main(String args[]){                  
                                                      
TongOne test1 = new TongOne("线程A");                  
TongOne test2 = new TongOne("线程B");                  
TongOne test3 = new TongOne("线程C");                  
                                                      
test1.start();                                        
test2.start();                                        
test3.start();                                        
                                                      
                                                      
}                                                      
}       

Answer 7

要保证执行顺序就要用join()方法等待前一个线程执行完
public class TongOne extends Thread{                      
private String cha;                                      
static Object printer = new Object();                    
public TongOne(String cha){                              
this.cha = cha;                                      
}                                                        
void print(){                                                                          
for(int i =1; i <=3;i++)                              
System.out.print（cha+ " ");                                                                          
}                                                        
public void run(){                                                                                       
for(int i =1;i <3;i++){                                
print();                                            
System.out.println();                                                                                 
}                                                    
                                                      
                                                      
}                                                  
public static void main(String args[]){                  
                                                      
TongOne test1 = new TongOne("线程A");                  
TongOne test2 = new TongOne("线程B");                  
TongOne test3 = new TongOne("线程C");                  
                                                      
test1.start();
test1.join();                                       
test2.start();
test2.join();                                       
test3.start();                                        
                                                      
                                                      
}                                                      
}      

Answer 8

8楼是正确的。
分析下原因吧。
A执行完run下面的for的一次循环以后，A休息去了，B上来干活了。
为什么啊，不是应该A做完了才能休息么。。不是啊，你的程序告诉我说，我只要执行print的时候不别人打断就行了，你又没说我在run中间不能被打断。
8楼的修改就达到了这个目的。

Answer 9

对于有严格顺序的同步执行，为啥要用多线程呢？直接单线程来的不是很快，更方便？
严重属于多线程滥用
去掉那些同步关键字吧,去掉多线程吧。直接调用run执行TongOne test1 = new TongOne("线程A");                  
TongOne test2 = new TongOne("线程B");                  
TongOne test3 = new TongOne("线程C"); test1.run();
test2.run();
test3.run();