Difference between "== operator" and "equals() method" in java

S.No	= = Operator	equals() method
1	It is used for reference comparison.	It is also used for reference comparison but if we want we can override for content comparison
2	It can be apply for both primitives and object references.	It can be apply for only object references.
3	s1==s2 is true, iff both s1 & s2 are pointing to the same object on the heap.	In the object class, .equals() returns true, iff both s1& s2 are pointing to the same object.
4	We can't apply == operator for incompatible types of objects violation leads to compile time exception saying incompatible types. Ex: String s1="getsure"; Student s2 = new Student("suresh"); SOP(s1==s2) --> C.E	It never rises any compile time / run time exception just it will simply returns false in the case of incompatible types.
5	In Identity Hashmap, JVM uses == operator to identify duplicate keys. Ex: IdentityHashMap m=new IdentityHashMap(); Integer i1=new Integer(10); Integer i2=new Integer(10); m.put(i1, "GetSure");m.put(i2, "Infotech"); SOP(m) --> O/P: 10 - GetSure, 10 - Infotech	In Hashmap, the JVM uses .equals() method to identify duplicate keys. Ex: HashMap m=new HashMap(); Integer i1=new Integer(10); Integer i2=new Integer(10); m.put(i1, "GetSure");m.put(i2, "Infotech"); SOP(m) --> O/P: Only 10 - Infotech