Exchanger类是一个同步辅助类,允许在并发任务之间交换数据。具体来说,Exchanger类允许在2个线程之间定义同步点。当2个线程都到达同步点时,他们交换数据结构,因此第一个线程的数据结构进入到第二个线程中,同时第二个线程的数据结构进入到第一个线程中。
代码:
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Exchanger;
public class Exchange1 implements Runnable{
private Exchanger<List<String>> exchanger;
public Exchange1(Exchanger<List<String>> exchanger) {
super();
this.exchanger = exchanger;
}
@Override
public void run() {
String name = Thread.currentThread().getName();
List<String> list = new ArrayList<>();
for(int i=0;i<5;i++){
list.add(i+"");
}
System.out.println(name+"之前的数据"+Arrays.toString(list.toArray()));
try {
Thread.sleep(3000);
//当前线程会阻塞 直到另一个exchange()被调用
List<String> list2 = exchanger.exchange(list);
System.out.println(name+"之后的数据"+Arrays.toString(list2.toArray()));
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Exchanger;
public class Exchange2 implements Runnable{
private Exchanger<List<String>> exchanger;
public Exchange2(Exchanger<List<String>> exchanger) {
super();
this.exchanger = exchanger;
}
@Override
public void run() {
String name = Thread.currentThread().getName();
List<String> list = new ArrayList<>();
for(int i=5;i<10;i++){
list.add(i+"");
}
System.out.println(name+"之前的数据"+Arrays.toString(list.toArray()));
try {
Thread.sleep(5000);
//当前线程会阻塞 直到另一个exchange()被调用
List<String> list2 = exchanger.exchange(list);
System.out.println(name+"之后的数据"+Arrays.toString(list2.toArray()));
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) {
Exchanger<List<String>> exchanger = new Exchanger<>();
Thread thread1 = new Thread(new Exchange1(exchanger));
Thread thread2 = new Thread(new Exchange2(exchanger));
thread1.start();
thread2.start();
}
}