Java

1. What String is. 2. Usage. 3. Source analysis: class definition, constructors, constant pool, equals, toCharArray, toString, valueOf, intern, and substring. 4. Common questions. 5. References.

What LinkedList is, usage, and source analysis of its doubly linked list, add/remove operations, and node traversal.

What LinkedHashMap is, insertion-order and access-order usage, and source analysis of construction, put, get, contains, remove, and iteration.

How to create an immutable object.

Usage, constructor, fields, other methods, and summary of LinkedHashSet.

1. What It Is: a thread-safe mutable string, essentially StringBuilder with synchronized methods. 2. Usage. 3. Implementation analysis: constructor, append, toString, and substring.

Convert Array to List and List to Array.

Comparison of HashMap 1.7 and 1.8, HashMap and Hashtable, and TreeMap, LinkedHashMap, and HashMap.

Synchronized Set wrappers and the need for external synchronization during compound operations and iteration.

1. What It Is: a mutable, thread-unsafe string. 2. Usage. 3. Implementation analysis: constructor, append, toString, and substring.