how to Monitor Synchronization in java

Monitor Synchronization

Java synchronization can cause a deadlock. The best way to avoid this problem is to avoid the use of Java synchronization. One of the most common uses of synchronization is to implement pooling of serially reusable objects. 

Often, you can simply add a serially reusable object to an existing pooled object. For example, you can add Java Database Connectivity (JDBC) and Statement object to the instance variables of a single thread model servlet, or you can use the Oracle JDBC connection pool rather than implement your own synchronized pool of connections and statements.

If you must use synchronization, you should either avoid deadlock, or detect it and break it. Both strategies require code changes. So, neither can be completely effective because some system code uses synchronization and cannot be changed by the application.

To prevent deadlock, simply number the objects that you must lock, and ensure that clients lock objects in the same order.
Proprietary JVM extensions may be available to help spot deadlocks without having to instrument code, but there are no standard JVM facilities for detecting deadlock.