题目:设计4个线程,其中两个线程每次对j增加1,另外连个每次对j减少1,循环100次。
java代码如下:
public class ThreadTest {
private int j;
public static void main(String[] args){
ThreadTest tt=new ThreadTest();
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(Thread.currentThread().getName()+"-inc:"+j);
}
private synchronized void dec() {
j--;
System.out.println(Thread.currentThread().getName()+"-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();
}
}
}
}