程序示例之多线程

设计四个线程，其中两个对j +1，另外两个对j -1：

一、使用内部类实现：

package com.test;


import org.junit.Test;


public class TestThread {


static int j = 0;


public static void main(String[] args) {
TestThread tt = new TestThread();
INC inc = tt.new INC();
DEC dec = tt.new DEC();
for (int i = 0; i < 2; i++) {
Thread t = new Thread(inc);
t.start();
t = new Thread(dec);
t.start();
}
}


private synchronized void inc() {
j++;
System.out.println("inc :" + j);
}


private synchronized void dec() {
j--;
System.out.println("dec :" + j);
}


class INC implements Runnable {
public void run() {
// TODO Auto-generated method stub
for (int i = 0; i < 100; i++) {
inc();
}
}
}


class DEC implements Runnable {
public void run() {
// TODO Auto-generated method stub
for (int i = 0; i < 100; i++) {
dec();
}
}
}
}

二、直接启动线程简单实现：

package com.test;


import org.junit.Test;


public class TestThread2 {


int j = 0;


@Test
public void test1() {
for (int i = 0; i < 2; i++) {
Thread t1 = new Thread(new Runnable() {


public void run() {
// TODO Auto-generated method stub
j++;
System.out.println("inc:" + j);
}
});


Thread t2 = new Thread(new Runnable() {


public void run() {
// TODO Auto-generated method stub
j--;
System.out.println("dec:" + j);
}
});


t1.start();
t2.start();


}


System.out.println("ressult:" + j);
}
}