Mode 9-Future

Come to Java multi-thread design mode

For a method that takes some time to execute, instead of waiting for the execution result to come out, it gets an alternative "Bill of Lading ".

Use Asynchronous Method call to separate the prepared and returned values.

 Public   Class Main { Public   Static   Void Main (string [] ARGs) {system. Out. println (" Main begin "); Host = New Host (); Data data1 = host. request (10, 'A'); Data data2 = host. request (20, 'B'); Data data3 = host. request (30, 'C '); System. Out. println (" Main otherjob begin ");Try {Thread. Sleep (2000 );} Catch (Interruptedexception e) {} system. Out. println (" Main otherjob end "); System. Out. println (" Data1 = "+ Data1.getcontent (); system. Out. println (" Data2 = "+ Data2.getcontent (); system. Out. println (" Data3 = "+ Data3.getcontent (); system. Out. println (" Main end ");}}

 

 Public   Class FuturedataImplements Data { Private Realdata = Null ; Private   Boolean Ready = False ; Public   Synchronized   Void Setrealdata (realdata ){ If (Ready ){ Return ; // Balk }This . Realdata = realdata; This . Ready = True ; Policyall ();} Public   Synchronized String getcontent (){ While(! Ready ){Try{Wait ();}Catch(Interruptedexception e ){}}          Return Realdata. getcontent ();}}

 
Host class
 

 Public   Class Host {PublicData Request (Final IntCount,Final CharC) {System. Out. println (" Request ( "+ Count +" , "+ C +" ) Begin "); // (1) Establish the object of futuredata          Final Futuredata future = New Futuredata (); // (2) Start a new thread to establish the realdata entity          New Thread (){ Public   Void Run (){ Realdata =NewRealdata (count, c); future. setrealdata (realdata ); }. Start (); system. Out. println (" Request ( "+ Count +" , "+ C +" ) End "); // (3) retrieve the futuredata object as the return value          Return Future ;}}