title: Passing address of an object to JNI and JNI method should populate the fields of that passed object
body: <p>I would like to pass the address of a java object and JNI method should populate the fields of the passed object. 
  1. The java code pass the given object reference. The JNI method should be able to cache this Object.  This is one time call. 
  2. Then the java object invokes the work native method repeatedly with different arguments and the JNI should be able to populate the fields of the cached object every time. It does not return anything but void, though it populates the same cached object. 
  3. The java after invoking the #work native methods uses the same object reference(passed during init) every time and gets the updated fields of the reference object. 
  4. The works method is frequently invoked (More than once) in a second. </p>
  
  <p>Discuss the design, the risk involved etc and any suggestion highly appreciated. 
  Note: Less emphasis on not using JNI, there are lots of thread already present. More importance on given JNI is there, the risk of Garbage collection, to use what kind of reference (global,weak) and is this design good/bad and how can be made better etc ? </p>
  
  <p>Expecting more responses </p>