Java 9 - CompletableFuture API 改进

曾经终败给现在 2023-10-13 20:33 11阅读 0赞

package com.lfsun.java9study.completablefuture;
    
    import java.util.concurrent.CompletableFuture;
    import java.util.concurrent.ExecutionException;
    import java.util.concurrent.Executor;
    import java.util.concurrent.Executors;
    import java.util.concurrent.TimeUnit;
    import java.util.concurrent.TimeoutException;
    
    public class CompletableFutureImprovementsExample {
        
    
        public static void main(String[] args) {
        
            // 示例1：newIncompleteFuture 方法
            CompletableFuture<String> future = new CompletableFuture<>();
            future.thenAccept(result -> System.out.println("Result: " + result));
    
            // 模拟在稍后的时间点完成 CompletableFuture
            new Thread(() -> {
        
                try {
        
                    TimeUnit.SECONDS.sleep(2);
                    future.complete("Hello, World thenAccept!");
                } catch (InterruptedException e) {
        
                    e.printStackTrace();
                }
            }).start();
    
            // 示例2：completeAsync 方法的增强
            Executor executor = Executors.newFixedThreadPool(4);
    
            CompletableFuture<String> future2 = new CompletableFuture<>();
            future2.completeAsync(() -> "Hello, World completeAsync!", executor)
                    .thenAccept(result -> System.out.println("Result: " + result));
    
            // 示例3：orTimeout 方法
            CompletableFuture<String> future3 = new CompletableFuture<>();
            future3.orTimeout(5, TimeUnit.SECONDS)
                    .exceptionally(throwable -> {
        
                        System.out.println("Timeout occurred!");
                        return null;
                    });
    
            try {
        
                TimeUnit.SECONDS.sleep(10);
            } catch (InterruptedException e) {
        
                e.printStackTrace();
            }
    
            // 等待所有任务完成
            try {
        
                future.get();
                future2.get();
            } catch (InterruptedException | ExecutionException e) {
        
                e.printStackTrace();
            } finally {
        
                System.out.println("all is complete!");
            }
        }
    }