多線程分批處理list內的值
阿新 • • 發佈:2017-09-17
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package three; import java.util.LinkedList; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; /** * * 這個方法沒有返回值,不能接到最後的處理結果 * */ public class MyExecutors { private static LinkedList<Integer> list = new LinkedList<Integer>(); public staticvoid main(String[] args) throws InterruptedException { for (int i = 0; i < 100; i++) { list.add(i); } // 創建線程池 ExecutorService executorService = Executors.newFixedThreadPool(90); for (Integer every : list) { executorService.execute(new Runnable() { @Override public void run() { System.out.println(Thread.currentThread().getName() + " " + every); } }); } System.out.println("------------------------------------------"); // 任務執行完畢後結束線程executorService.shutdown(); } }
//---------------------------------------------------下面的這個類是智慧的網友寫的,有返回值--------------------------------------------------------------------------
package four; import java.util.ArrayList; import java.util.List; import java.util.concurrent.Callable; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; public class CunsumerList { public static void main(String[] args) { try { List<String> list = new ArrayList<>(); for (int i = 0; i < 100; i++) { list.add(i + ","); } System.out.println(new CunsumerList().list2Str(list, 5)); } catch (Exception e) { e.printStackTrace(); } } /** * 這個能知道線程的處理結果,因為有返回值 * @param list * @param nThreads * @return * @throws Exception */ public String list2Str(List<String> list, final int nThreads) throws Exception { if (list == null || list.isEmpty()) { return null; } StringBuffer ret = new StringBuffer(); int size = list.size(); ExecutorService executorService = Executors.newFixedThreadPool(nThreads); List<Future<String>> futures = new ArrayList<Future<String>>(nThreads); for (int i = 0; i < nThreads; i++) { final List<String> subList = list.subList(size / nThreads * i, size / nThreads * (i + 1)); Callable<String> task = new Callable<String>() { @Override public String call() throws Exception { System.out.println(Thread.currentThread().getName()); StringBuffer sb = new StringBuffer(); for (String str : subList) { sb.append(str); } return sb.toString(); } }; futures.add(executorService.submit(task)); } for (Future<String> future : futures) { ret.append(future.get()); } executorService.shutdown(); return ret.toString(); } }
多線程分批處理list內的值