java future设计模式

1、数据接口层：

package multithread;

public interface Data2 {

public abstract String getContent();
}

2、真实数据层：

package multithread;

public class RealData implements Data2{

private final String content;

public RealData(int count,char c){
   System.out.println(" making realdata("+count+","+c+") begin");
   char buffer[] = new char[count];
   for(int i=0;i<count;i++){
    buffer[i] = c;
    try {
     Thread.sleep(100);
    } catch (InterruptedException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
  
   System.out.println(" making realdata("+count+","+c+") end");
   this.content = new String(buffer);
}
public String getContent(){
   return content;
}
}

3、虚拟数据层（提货单）：

package multithread;

/**
* @author Administrator
*提货单
*/
public class FutureData implements Data2{

private RealData realdata = null;
private boolean ready = false;

public synchronized String getContent(){
   while(!ready){
    try {
     wait();
    } catch (InterruptedException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
  
   return realdata.getContent();
}

public synchronized void setRealData(RealData realdata){
   if(ready)
    return ;
   this.realdata = realdata;
   this.ready = true;
   notifyAll();
}
}

4、处理数据层：

package multithread;

public class Host2 {

public Data2 request(final int count,final char c){
   System.out.println(Thread.currentThread().getName()+" ....");
   System.out.println(" request("+count+", "+c+") begin");
   final FutureData future = new FutureData();
   //System.out.println(future.toString());
   new Thread(){
    public void run(){
     RealData realdata = new RealData(count ,c);
     future.setRealData(realdata);
    }
   }.start();
  
   System.out.println(" request("+count+", "+c+") end");
   return future;
}
}

5、测试类：

package multithread;

public class Main5 {

public static void main(String args[]){
   System.out.println("main begin");
   Host2 host = new Host2();
   Data2 data1 = host.request(10, 'A');
   Data2 data2 = host.request(20, 'B');
   Data2 data3 = host.request(30, 'C');
  
   System.out.println("main otherjob begin");
  
   try {
    Thread.sleep(2000);
   } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
   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");
}
}