在本教程中，我们将了解executor的newcachedthreadpool工厂方法。

在最后一个教程中，我已经共享了ThreadPoolExecutor的简介。
如果我们不了解ThreadPoolExecutor的概念，则应首先通过它。

executor的newcachedthreadpool工厂方法：

此方法返回一个无限的线程池。
它将最大池大小设置为Integer.max，它将根据需求创建新线程。
如果需求减少，如果线程空转超过1分钟，它将撕下线程。

例子：

让我们创建一项任务。
此处任务将是读取不同的文件并处理它们。

package org.igi.theitroad.bean;
 
public class FetchDataFromFile implements Runnable{
 
 private final String fileName;
 
 public FetchDataFromFile(String fileName) {
 super();
 this.fileName = fileName;
 }
 
 @Override
 public void run() {
 try {
 System.out.println("Fetching data from "+fileName+" by "+Thread.currentThread().getName());
 Thread.sleep(5000); //Reading file
 System.out.println("Read file successfully: "+fileName+" by "+Thread.currentThread().getName());
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 }
 public String getFileName() {
 return fileName;
 }
}

让我们创建一个将消耗上面的任务并处理它的ThreadPoolExecutor。

package org.igi.theitroad;
 
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
 
public class ThreadPoolExecutorMain {
 public static void main(String args[]) {
   //Getting instance of ThreadPoolExecutor using  Executors.newCachedThreadPool factory method
  ThreadPoolExecutor threadPoolExecutor = (ThreadPoolExecutor) Executors.newCachedThreadPool();
 
  for (int i = 1; i <= 10; i++) {
   FetchDataFromFile fdff = new FetchDataFromFile("File :" + i);
   System.out.println("A new file has been added to read : " + fdff.getFileName());
   threadPoolExecutor.execute(fdff);
  }
  threadPoolExecutor.shutdown();
 }
}

运行上面的程序时，我们将得到以下输出：

A new file has been added to read : File :1
A new file has been added to read : File :2
Fetching data from File :1 by pool-1-thread-1
Fetching data from File :2 by pool-1-thread-2
A new file has been added to read : File :3
A new file has been added to read : File :4
Fetching data from File :3 by pool-1-thread-3
Fetching data from File :4 by pool-1-thread-4
A new file has been added to read : File :5
Fetching data from File :5 by pool-1-thread-5
A new file has been added to read : File :6
Fetching data from File :6 by pool-1-thread-6
A new file has been added to read : File :7
Fetching data from File :7 by pool-1-thread-7
A new file has been added to read : File :8
A new file has been added to read : File :9
Fetching data from File :8 by pool-1-thread-8
A new file has been added to read : File :10
Fetching data from File :9 by pool-1-thread-9
Fetching data from File :10 by pool-1-thread-10

如果我们注意到，我们已提交10个任务，并且它根据需求创建了10个新线程。
如果任何线程保持闲置超过一分钟，则它将撕下它。
当我们想要比NewFixedThreadPool更好的排队性能，NewCachedThreadPool是一个不错的选择。
如果要限制资源管理的并发任务数，请使用newfixedthreadpool。