我建议看一下ExecutorService。
特别是这样的事情：
ExecutorService EXEC = Executors.newCachedThreadPool();List<Callable<Result>> tasks = new ArrayList<Callable<Result>>();for (final Object object: objects) { Callable<Result> c = new Callable<Result>() { @Override public Result call() throws Exception { return compute(object); } }; tasks.add(c);}List<Future<Result>> results = EXEC.invokeAll(tasks);请注意，
newCachedThreadPool如果
objects列表很大，使用可能会很糟糕。缓存的线程池可以为每个任务创建一个线程！您可能想
newFixedThreadPool(n)在n合理的地方使用（例如，假设
compute()CPU受限制，则具有的内核数）。
这是实际运行的完整代码：
import java.util.ArrayList;import java.util.List;import java.util.Random;import java.util.concurrent.Callable;import java.util.concurrent.ExecutionException;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.Future;public class ExecutorServiceExample { private static final Random PRNG = new Random(); private static class Result { private final int wait; public Result(int pre) { this.wait = pre; } } public static Result compute(Object obj) throws InterruptedException { int wait = PRNG.nextInt(3000); Thread.sleep(wait); return new Result(wait); } public static void main(String[] args) throws InterruptedException, ExecutionException { List<Object> objects = new ArrayList<Object>(); for (int i = 0; i < 100; i++) { objects.add(new Object()); } List<Callable<Result>> tasks = new ArrayList<Callable<Result>>(); for (final Object object : objects) { Callable<Result> c = new Callable<Result>() { @Override public Result call() throws Exception { return compute(object); } }; tasks.add(c); } ExecutorService exec = Executors.newCachedThreadPool(); // some other exectuors you could try to see the different behaviours // ExecutorService exec = Executors.newFixedThreadPool(3); // ExecutorService exec = Executors.newSingleThreadExecutor(); try { long start = System.currentTimeMillis(); List<Future<Result>> results = exec.invokeAll(tasks); int sum = 0; for (Future<Result> fr : results) { sum += fr.get().wait; System.out.println(String.format("Task waited %d ms", fr.get().wait)); } long elapsed = System.currentTimeMillis() - start; System.out.println(String.format("Elapsed time: %d ms", elapsed)); System.out.println(String.format("... but compute tasks waited for total of %d ms; speed-up of %.2fx", sum, sum / (elapsed * 1d))); } finally { exec.shutdown(); } }}
