Java synchronization method and synchronization code block, Object lock, Class lock Difference

/** * @author Admin * @date 2018/1/12 9:48 * Function on the same instance object to discuss * synchronized Synchronous method Test * Two threads, one thread calls synchronized adornment method, another thread can call non s Ynchronized modified method, non-impact */public class Synchronizedtest {public synchronized void MethodA () {try {fo                R (int i = 0; i < 5; i++) {System.out.println ("methoda-" + i);            Thread.Sleep (1000);        }} catch (Interruptedexception e) {e.printstacktrace (); }} public void MethodB () {try {for (int i = 0; i < 5; i++) {System.out.print                ln ("methodb-" + i);            Thread.Sleep (1000);        }} catch (Interruptedexception e) {e.printstacktrace ();        }} public static void Main (string[] args) {synchronizedtest test = new Synchronizedtest (); Thread thread1 = new Thread (new Runnable () {@Override public void run () {Test.metho            DA ();        }        }); THread1.start (); Thread thread2 = new Thread (new Runnable () {@Override public void run () {Test.metho            DB ();        }        });    Thread2.start (); }} Run Result: methoda-0methodb-0methoda-1methodb-1methodb-2methoda-2methoda-3methodb-3methoda-4methodb-4

 

/** * @author Admin * @date 2018/1/12 10:16 * Function on the same instance object to discuss * sychronized code block Test * Two threads, one thread executes synchronized code block, another thread executes non-synch                Ronized code block */public class SychronizedTest2 {public void MethodA () {synchronized (this) {try {                    for (int i = 0; i < 5; i++) {System.out.println ("methoda-" + i);                Thread.Sleep (1000);            }} catch (Interruptedexception e) {e.printstacktrace (); }}} public void MethodB () {try {for (int i = 0; i < 5; i++) {System.                Out.println ("methodb-" + i);            Thread.Sleep (1000);        }} catch (Interruptedexception e) {e.printstacktrace ();        }} public static void Main (string[] args) {SychronizedTest2 test2 = new SychronizedTest2 (); Thread thread1 = new Thread (new Runnable () {@Override public void run () {tesT2.methoda ();        }        });        Thread1.start (); Thread thread2 = new Thread (new Runnable () {@Override public void run () {Test2.meth            OdB ();        }        });    Thread2.start (); }} Run Result: methoda-0methodb-0methoda-1methodb-1methoda-2methodb-2methodb-3methoda-3methoda-4methodb-4

 

/** * @author Admin * @date 2018/1/12 10:33 * Function on the same instance object discussion * Synchronized synchronous method and Synchronous code block * 1, synchronized, and synchronized (this) both    No difference, all functions on the This object lock, so will synchronize * 2, synchronized (obj), this is on the Obj object lock, and this object lock is different, so will not synchronize */public class SynchronizedTest3 { Public synchronized void MethodA () {try {for (int i = 0; i < 5; i++) {SYSTEM.OUT.PR                Intln ("methoda-" + i);            Thread.Sleep (1000);        }} catch (Interruptedexception e) {e.printstacktrace (); }} public void MethodB () {synchronized (this) {try {for (int i = 0; i < 5; I                    + +) {System.out.println ("methodb-" + i);                Thread.Sleep (1000);            }} catch (Interruptedexception e) {e.printstacktrace ();        }}} public void Methodc () {Object obj = new Object (); Synchronized (obj) {try {for (int i = 0; i< 5;                    i++) {System.out.println ("methodc-" + i);                Thread.Sleep (1000);            }} catch (Interruptedexception e) {e.printstacktrace ();        }}} public static void Main (string[] args) {SynchronizedTest3 test3 = new SynchronizedTest3 (); Thread thread1 = new Thread (new Runnable () {@Override public void run () {test3.            MethodA ();        }        });        Thread1.start (); Thread thread2 = new Thread (new Runnable () {@Override public void run () {Test3.meth            OdB ();        }        });        Thread2.start (); Thread thread3 = new Thread (new Runnable () {@Override public void run () {Test3.meth            OdC ();        }        });    Thread3.start (); }} Run Result: Methoda-0methodc-0methoda-1methodc-1methoda-2methodc-2methoda-3methodc-3methoda-4methodc-4methodb-0meThodb-1methodb-2methodb-3methodb-4 

 

/** * @author Admin * @date 2018/1/12 10:48 * function is discussed on the same class, each class has only one class lock * Synchronized class lock * static synchronized and synchronized (  Synchronizedtest4.class), all functions are locked in the same class, so sync */public class SynchronizedTest4 {public synchronized static void MethodA ()                {try {for (int i = 0; i < 5; i++) {System.out.println ("methoda-" + i);            Thread.Sleep (1000);        }} catch (Interruptedexception e) {e.printstacktrace ();  }} public void MethodB () {synchronized (synchronizedtest4.class) {a try {for (int i = 0; I < 5;                    i++) {System.out.println ("methodb-" + i);                Thread.Sleep (1000);            }} catch (Interruptedexception e) {e.printstacktrace ();        }}} public static void Main (string[] args) {SynchronizedTest4 test4 = new SynchronizedTest4 (); Thread thread1 = new Thread (new Runnable() {@Override public void run () {Test4.methoda ();        }        });        Thread1.start (); Thread thread2 = new Thread (new Runnable () {@Override public void run () {Test4.meth            OdB ();        }        });    Thread2.start (); }} Run Result: methoda-0methoda-1methoda-2methoda-3methoda-4methodb-0methodb-1methodb-2methodb-3methodb-4

 

/** * @author Admin * @date 2018/1/12 11:03 * Synchronized object lock and static synchronized class lock, is two different locks, so will not sync * Two threads, one call object lock, one call class lock */public class SynchronizedTest5 {public synchronized void MethodA () {try {for (int i = 0; I &lt ; 5;                i++) {System.out.println ("methoda-" + i);            Thread.Sleep (1000);        }} catch (Interruptedexception e) {e.printstacktrace ();                }} public synchronized static void MethodB () {try {for (int i = 0; i < 5; i++) {                System.out.println ("methodb-" + i);            Thread.Sleep (1000);        }} catch (Interruptedexception e) {e.printstacktrace ();        }} public static void Main (string[] args) {SynchronizedTest5 test5 = new SynchronizedTest5 (); Thread thread1 = new Thread (new Runnable () {@Override public void run () {Test5.meth            OdA ();     }        });   Thread1.start (); Thread thread2 = new Thread (new Runnable () {@Override public void run () {Test5.meth            OdB ();        }        });    Thread2.start (); }} Run Result: methoda-0methodb-0methoda-1methodb-1methodb-2methoda-2methodb-3methoda-3methodb-4methoda-4

Java synchronization method and synchronization code block, Object lock, Class lock Difference