我有两个问题,关于这个代码:ConcurrentModificationException的用Java 1.8.0_45
import java.util.*;
public class TestClass {
private static List<String> list;
public static void main(String[] argv) {
list = generateStringList(new Random(), "qwertyuioasdfghjklzxcvbnmPOIUYTREWQLKJHGFDSAMNBVCXZ1232456789", 50, 1000);
// Collections.sort(list, new Comparator<String>() {
// public int compare(String f1, String f2) {
// return -f1.compareTo(f2);
// }
// });
for (int i = 0; i < 500; i++) {
new MyThread(i).start();
}
}
private static class MyThread extends Thread {
int id;
MyThread(int id) { this.id = id; }
public void run() {
Collections.sort(list, new Comparator<String>() {
public int compare(String f1, String f2) {
return -f1.compareTo(f2);
}
});
for (Iterator it = list.iterator(); it.hasNext();) {
String s = (String) it.next();
try {
Thread.sleep(10 + (int)(Math.random()*100));
}catch (Exception e) { e.printStackTrace(); }
System.out.println(id+" -> "+s);
}
}
}
public static List<String> generateStringList(Random rng, String characters, int length, int size)
{
List<String> list = new ArrayList<String>();
for (int j = 0; j < size; j++) {
char[] text = new char[length];
for (int i = 0; i < length; i++)
{
text[i] = characters.charAt(rng.nextInt(characters.length()));
}
list.add(new String(text));
}
return list;
}
}
运行于Java 1.8.0_45这个代码我得到java.util.ConcurrentModificationException
。
1)为什么我得到了异常,如果我在thread.start之前对这种排序进行了分解?
2)为什么我只在java 1.8.0_45上遇到异常?在1.6.0_45,1.7.0_79,1.8.0_5上它工作正常。
感谢您的解释,任何建议的修复? – ronnyfm
@ronnyfm修复不是要同时使用多个线程对集合进行排序。你不应该那样做。 – eis