thread_lock_be_modify.java

java 线程 静态锁

package thread_lock_be_modify;

import java.util.Vector;

public class Thread_lock_be_modify {
	private static final class Thread_lock_be_modifyHolder {
		private static Thread_lock_be_modify theSingleton = new Thread_lock_be_modify();

		public static Thread_lock_be_modify getSingleton() {
			return theSingleton;
		}
		public static Thread_lock_be_modify getInstance() {
			return Thread_lock_be_modifyHolder.getSingleton();
		}

		private Thread_lock_be_modifyHolder() {
		}
	}

	
	private Vector ve = null;
	private Object lock = new Object();

	private Thread_lock_be_modify() {
		ve = new Vector();
		initialize();
	}

	public void reload() {
		synchronized (lock) {
			ve = null;
			ve = new Vector();
			// lock="abc";
			for (int i = 0; i < 100; i++) {
				ve.add(String.valueOf(i));
			}
		}
		System.out.println("reload end");
	}

	private void initialize() {
		for (int i = 0; i < 100; i++) {
			ve.add(String.valueOf(i));
		}
	}

	public boolean checkValid(String str) {
		synchronized (lock) {
			System.out.println(ve.size());
			return ve.contains(str);
		}
	}
	
	
}