Holding onto an Object Until Memory Becomes Low
A soft reference holds onto its referent until memory becomes low. 

 // Create up the soft reference.
 SoftReference sr = new SoftReference(object);
     
 // Use the soft reference.
 Object o = sr.get();
 if (o != null) {
   process(o);
   } else {
   // The object is being collected or has been reclaimed.
 }