總之前返回 - 所有你需要的是這樣的 -
CompletableFuture.supplyAsync(this::supplySomething, ex).thenAccept(this::consumer);
您需要一種方法是將調用執行程序(線程池)。在我的情況下,我的游泳池大小爲100.接下來,您需要根據需要多次致電您的供應商。
每次調用'supplier'都會創建一個任務。我正在創建10000個任務。他們每個人都會並行運行,每個人完成後都會打電話給我的'消費者'。
您的供應商應該返回某種對象,該對象持有來自webservice的響應。這個對象將成爲你的'消費者'方法的參數。
您可能想要在完成所有操作後(或中間)殺死池。
請參見下面的例子 -
package com.sanjeev.java8.thread;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
public class Caller {
public static ExecutorService ex = Executors.newFixedThreadPool(100);
public static void main(String[] args) throws InterruptedException {
Caller caller = new Caller();
caller.start();
ex.shutdown();
ex.awaitTermination(10, TimeUnit.MINUTES);
}
private void start() {
for (int i = 0; i < 10000; i++) {
CompletableFuture.supplyAsync(this::supplySomething, ex).thenAccept(this::consumer);
}
}
private int supplySomething() {
try {
URL url = new URL("http://www.mywebservice.com");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
connection.setDoInput(true);
connection.connect();
try (DataOutputStream wr = new DataOutputStream(connection.getOutputStream())) {
wr.write("supply-some-data".getBytes());
}
Reader in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
for (int c; (c = in.read()) >= 0;) {
System.out.print((char) c);
}
in.close();
// return the response code. I'm return 'int', you should return some sort of object.
return 200;
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
public void consumer(Integer i) {
// This parameter should be of type 'your object' that supplier returned.
// I got the response; add it in the list or whatever....
}
}
另一個例子可能適合您需要更好 -
public class Caller2 {
public static ExecutorService ex = Executors.newFixedThreadPool(2);
private static Iterator<String> addresses = Stream.of("www.google.com", "www.yahoo.com", "www.abc.com").collect(Collectors.toList()).iterator();
private static ArrayList<String> results = new ArrayList<>();
public static void main(String[] args) throws InterruptedException {
Caller2 caller = new Caller2();
caller.start();
ex.shutdown();
ex.awaitTermination(1, TimeUnit.HOURS);
System.out.println(results);
}
private void start() {
while (addresses.hasNext()) {
CompletableFuture.supplyAsync(this::supplyURL, ex).thenAccept(this::consumer);
}
}
private String supplyURL() {
String url = addresses.next();
// call this URL and return response;
return "Success";
}
public void consumer(String result) {
results.add(result);
}