java多线程系列之杂谈|第一篇：Thread-Per-Message

含义：将一些额外的操作进行异步处理。

范例程序：Main类委托Host类显示文字。Host启动一个线程来处理这项委托的工作。

顺序图如下：

示例代码：

Host

package pattern.perthread;

public class Host {

    private final Helper helper=new Helper();

    public void request(final int count,final char c){
        System.out.println("   request( "+count+","+c+") begin");
        new Thread(new Runnable() {
            @Override
            public void run() {
                helper.handle(count,c);
        }
        }).start();
        System.out.println("   request( "+count+","+c+") end");
    }

}

Helper

package pattern.perthread;

public class Helper {

    public void handle(int count,char c){
        System.out.println("   handle( "+count+","+c+") begin");
        for (int i = 0; i < count; i++) {
            slowly();
            System.out.println(c);
        }
        System.out.println("");
        System.out.println("   handle( "+count+","+c+") end");
    }

    private  void slowly(){
        try{
            Thread.sleep(100);
        }catch (java.lang.InterruptedException e){
            e.printStackTrace();
        }
    }

}

Main

package pattern.perthread;

public class Main {

    public static void main(String[] agrs){
        System.out.println("main begin");
        Host host=new Host();
        host.request(2,'A');
        host.request(3,'B');
        host.request(5,'C');
        System.out.println("main end");
    }


}

测试结果：

main begin
   request( 2,A) begin
   request( 2,A) end
   request( 3,B) begin
   request( 3,B) end
   handle( 2,A) begin
   request( 5,C) begin
   request( 5,C) end
main end
   handle( 3,B) begin
   handle( 5,C) begin
C
A
B
A
C
B

   handle( 2,A) end
C
B

   handle( 3,B) end
C
C

   handle( 5,C) end

SUCCESS。