Some small demo of multithreading

One, multiple threads, single lock

 PackageCom.sun.multithread.sync; Public classMyThreadextendsThread {Private intCount = 5; //Synchronized Locking     Public synchronized voidRun () {count--; System.out.println ( This. CurrentThread (). GetName () + "Count =" +count); }         Public Static voidMain (string[] args) {MyThread MyThread=NewMyThread (); Thread T1=NewThread (MyThread, "T1"); Thread T2=NewThread (MyThread, "T2"); Thread T3=NewThread (MyThread, "T3"); Thread T4=NewThread (MyThread, "T4"); Thread T5=NewThread (MyThread, "T5");        T1.start ();        T2.start ();        T3.start ();        T4.start ();    T5.start (); }}

Two, multiple lines multithreading lock

 PackageCom.sun.multithread.sync; Public classmultithread {Private Static intnum = 0; /*** Add synchronized keyword to static method, means lock class class, Class-level lock * keyword synchronized acquired lock is object lock, rather than a piece of code (method) as a lock, * so which thread in the code executes the first synch Ronized method of the keyword, which thread holds the lock of the object to which the method belongs *@paramTag Parameter*/     Public Static synchronized voidprintnum (String tag) {Try {            if(Tag.equals ("a") ) {num= 100; System.out.println ("Tag A, set num over!"); Thread.Sleep (1000); } Else{num= 200; System.out.println ("Tag b, set num over!"); } System.out.println ("Tag" + tag + ", num =" +num); } Catch(interruptedexception e) {e.printstacktrace (); }    }         Public Static voidMain (string[] args) {//two different objects        FinalMultithread M1 =Newmultithread (); Finalmultithread m2 =Newmultithread (); Thread T1=NewThread (NewRunnable () {@Override Public voidrun () {M1.printnum (A);                }        }); Thread T2=NewThread (NewRunnable () {@Override Public voidrun () {M1.printnum ("B");                }        });        T1.start ();    T2.start (); }}

Some small demo of multithreading