public class JsonUtil {
    private static final ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();
    private static final Lock rLock = rwl.readLock();
    private static final Lock wLock = rwl.writeLock();
        
       public static void read(){
              try{
                   rLock.lock();
                   读的一些操作。。。。。

               } finally {
           rLock.unlock();
           }
       }

       public static void write(){
              try{
                   wLock.lock();
                   写的一些操作。。。。。

               } finally {
           wLock.unlock();
           }
       }