多线程死锁的简单使用：

public class MyLock{    public static final Object locka=new Object();    public static final Object lockb=new Object();    public static final Object lockc=new Object();    public static final Object lockd=new Object();}

package day_12_01_Thread;/** * 死锁的情况 *  * @author Administrator * */public class TestSynchronized implements Runnable {    public static void main(String[] args) {        TestSynchronized s = new TestSynchronized();        Thread t1 = new Thread(s);        Thread t2 = new Thread(s);        t1.start();        t2.start();    }    @Override    public void run() {        int i = 0;        while (true) {            if (i % 2 == 0) {                synchronized (MyLock.locka) {                    System.out.println("if.......locka");                    synchronized (MyLock.lockb) {                        System.out.println("if ...........lockb");                    }                }            } else {                synchronized (MyLock.lockb) {                    System.out.println("else..........lockb");                    synchronized (MyLock.locka) {                        System.out.println("else..........locka");                    }                }            }            i++;        }    }}