一个简单的java缓存类

package cn.com.chnsys.imp.dcs.ledict.utils;

import java.util.HashMap;
import java.util.Map;

import com.alibaba.fastjson.JSONObject;


/**
 * 
律典通token缓存
 *
 *
 * @author wangming
 * @version 1.0
 */
public class LedictTokenCache {
    /**
     * token Server管理Map
     */
    private static Map ledictTokenMap = new HashMap();
    
    private static LedictTokenCache ledictTokenCache;
    
    private LedictTokenCache() {}
    
    public static LedictTokenCache getInstance() {
        if(ledictTokenCache == null) {
            synchronized (LedictTokenCache.class) {
                if(ledictTokenCache == null) {
                    ledictTokenCache = new LedictTokenCache();
                }
            }
        }
        return ledictTokenCache;
    }
    
    /**
     * 向律token Map中添加数据
     */
    public synchronized static void addLedictToken(String loginName,JSONObject body) {
        ledictTokenMap.put(loginName, body);
    }
    /**
     * 获取token配置
     * @return  律典通配置
     */
    public synchronized static JSONObject getLedictToken(String loginName){
        return ledictTokenMap.get(loginName);
    }

    /**
     * 根据登录名删除token缓存中数据
     */
    public synchronized static void deleteLedictToken(String loginName) {
        ledictTokenMap.remove(loginName);
    }
    /**
     * 删除token缓存中数据
     */
    public synchronized static void deleteLedictAllToken() {
        ledictTokenMap.clear();
    }
}