java resolves deadlock (program emulation) __java

In order to solve the program because of resources, there is a scramble for resources, and the resulting program into the waiting state (deadlock).

To address this problem:

We can add a "lock" to the resource, determine the status of the current lock before each call, and then execute.

The following is an emulator:

Package com.yxy.thread;
Import Java.util.concurrent.locks.Lock;
Import Java.util.concurrent.locks.ReentrantLock;

Import Java.util.Random; /** * @author Windows * Security Lock example/public class Safelock {/** * @author Windows * Friends entity class * * * stat
        IC class Friend {//friend class, lock (re-lock) private final String name;
        Private Final lock lock = new Reentrantlock ();
        Friend construct method public friend (String name) {this.name = name;
        //Gets the name public String GetName () {return this.name; ///Before bowing judgment public boolean impendingbow (friend Bower) {//Current my state lock, with friend's state lock Boolean myl
            Ock = false;
            Boolean Yourlock = false;
                try {//Record the lock of the current class, and the state of the lock of the bowing friend MyLock = Lock.trylock ();
            Yourlock = Bower.lock.tryLock (); finally {//if the current class is locked, with a bow friend's class state, where there is a false if (!) (MyLock && yourLock)) {//The judge is the one whose state is true to unlock the lock.
                    if (myLock) {lock.unlock ();
                    } if (Yourlock) {bower.lock.unlock ();
        }}//Return results MyLock && Yourlock; 
        	/** * @param Bower * The way to bow to friends * * public void bow (friend Bower) { Determine if there is a lock if (Impendingbow (bower)) {//friend bowed when I did not bow.
                Print out the information and return it. 
                        try {System.out.format ('%s:%s has ' + ' bowed to me!%n ')
                    THIS.name, Bower.getname ());
                Bower.bowback (this);
                    finally {Lock.unlock ();
                Bower.lock.unlock (); } else {//friends bow while I bow.
                Print out the information. System.out.format ("%S:%s started "+" to bow to me, but saw that "+" I am already bowing to "
            + "him.%n", THIS.name, Bower.getname ());
         }/** * @param bower * The method of bowing. */public void Bowback (Friend bower) {System.out.format ('%s:%s has ' + ' bowed back t
        o me!%n ", this.name, Bower.getname ()); }/** * @author windows * Loop bowed thread/static class Bowloop implements Runnable {//bow to each other
        Two persons private Friend bower;

        Private Friend Bowee;
            Construction method Public Bowloop (friend Bower, friend Bowee) {this.bower = bower;
        This.bowee = Bowee;
            //thread execution method public void run () {Random Random = new Random (); for (;;)
                {//infinite loop. try {//process interrupt THREAD.SLEep (Random.nextint (5));
            The catch (Interruptedexception e) {}//bowee bowed to the Bower Bowee.bow (Bower);
            }}//test public static void main (string[] args) {final Friend alphonse =
        New Friend ("Alphonse");
        Final friend Gaston = new Friend ("Gaston");
        New Thread (New Bowloop (Alphonse, Gaston)). Start ();
    New Thread (New Bowloop (Gaston, Alphonse)). Start ();
 }
}