Core java Interview question

CORE JAVA API
Q what are the api in core java
Q what are the object class method in java

1)what is oops concept with example
  a-abstraction
  b-incapsulation
  c-polymorphism
  d-inheritance
2)what is exception handling
3)difference between checked and inchecked exception
4)difference between throw and throws
5)how to make custome exception
5)what is super class of exception
6)how many way we can create object
7)difference between abstract class and interface with example
8)diffrence between encapsulation and abstraction
9)diffrence between overloading and overriding
10)diffrence between thread class and runnable interface
11)diffrence between wait and sleep
12)what is pojo class
13) why we write setter and getter method
14)if i make cnstructor as a private than how will create object
15)difference between default constructor and parameter constructor
16)why we write default constructor in pojo class
17)diffrence between super and this keyword
18)how jvm work
19)diffrence between class path and path
20)what is static in details

STRING IN JAVA DEVELOPMENT

1)what is immutable example like all wrapper class example of immutable
2)how to  make immutable class
3)diffrence between string buffer and string builder


COLLECTIONS INTERVIEW QUESTION

1)what is collection
2)diffrence between linkedlist and array list
3)diffrence between hashset and linkedhashset
4)diffrence between treemap and  treeset
5)diffrence between map and hashmap
6)diffrence between hashmap and hashtable
7)diffrence between list and set
8)diffrence between iterator and listiterator
9)when to use hashMap
10)diffrence between arraylist and vector

11) how the collision handle in hashMap
12)is there any collection where you can store key value pair key has to be in sorted order
13)can we add employee object into hashMap or not as a key
14)how hash map work internally

15)diffrence between comprable and comprator
16)suppose i want to sort by empname and empAge
17)i wnat to sort empName and DeptName at a time
18)why we overrrid hashCode if i overrided equal method give me reason

19) what is serilization
20)how to implement serilization
21)what is syncronization
22)which collections  classes are syncronized or thredsafe