java 根据value进行并发同步操作

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.Semaphore;

public abstract class ValueSynLock<T,K> {

/**
* @Fields signMap : TODO(存储一个同步信号量，key表示同步的值)
*/
private static  ConcurrentMap<Object, Semaphore> signMap = new ConcurrentHashMap<Object, Semaphore>();
/**
* 要执行的方法
* @throws Exception
*/
public abstract K run();
/**
* 开始执行操作
* @param value
* @throws Exception
*/
public K startWork(T value) throws Exception {
Semaphore se = putMapAndGetSemaphore(value);
K ret = null;
try {
se.acquire();
ret=run();
releaseLockMap(value);
} catch (Exception e) {
e.printStackTrace();
}finally{
se.release();
}
return ret;
}
/**
* 释放map
* @param
*/
public void releaseLockMap(T a) {
Semaphore se = signMap.get(a);
if (se != null) {
signMap.remove(a);
}
}
/**
*
* @param 放入同步值，获取同步信号量
* @return
*/
public Semaphore putMapAndGetSemaphore(T value) {
Semaphore se = signMap.get(value);
if (se == null) {
se = new Semaphore(1);
signMap.put(value, se);
}
return signMap.get(value);
}
}