java 线程返回值

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1.传统方式需要新建一个接口类,然后在接口类中将结果在方法中作为参数进行处理

package de.bvb.test3;public class Test3 {
public static void main(String[] args) throws Exception { Thread t = new Thread(new MyRunnable(6, new Callback<Long>() { @Override
public void handler(Long result) {
System.out.println(result);
}
}));
t.start(); }
}interface Callback<T> {
void handler(T result);
}class MyRunnable implements Runnable {
private long num;
private Callback<Long> callback; public MyRunnable(long num, Callback<Long> callback) {
super();
this.num = num;
this.callback = callback;
} @Override
public void run() {
long result = -1l;
if (num > 0) { // 计算阶乘
result = 1;
for (int i = 2; i < num; i++) {
result *= i;
}
}
if (callback != null) {
callback.handler(result);
}
}
}

2.可以使用java5的新特性,实现Callable这个接口

package de.bvb;import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;public class Test2 {
public static void main(String[] args) throws Exception {
ExecutorService pool = Executors.newFixedThreadPool(1);
Future<Long> f1 = pool.submit(new MyCallable(5));
System.out.println(f1.get().toString());
pool.shutdown();
}
}class MyCallable implements Callable<Long> {
private long num; public MyCallable(long num) {
super();
this.num = num;
} @Override
public Long call() throws Exception {
long result = -1l;
if (num > 0) {
result = 1l;
for (int i = 2; i < num; i++) {
result *= i;
}
}
return result;
}}