Java Tutorials - Herong's Tutorial Examples - v8.22, by Herong Yang
Creating Class Type Objects
This section describes how class type objects can be created using the 'new' operator and special methods.
There are a number of ways to create a class type object:
1. The "new" operator - A class type object can be created using the new operator to call the class constructor. Examples are listed below:
new String("Hello"); // creates a String object
new java.util.Date(); // creates a Date object
new java.util.ArrayList<String>(); // creates an ArrayList<String>
2. Special method - A class type object can be created using special methods provided by classes. Examples are listed below:
javax.net.SocketFactory.getDefault().createSocket();
// creates a java.net.Socket object
java.security.KeyPairGenerator.getInstance("DSA");
// creates a java.security.KeyPairGenerator object
3. String literal and String concatenation - A String type object can be created using a String literal or a String concatenation. Examples are listed below:
"Hello" // creates a String object "Hello"+" world!" // creates a String object
Table of Contents
Execution Process, Entry Point, Input and Output
Primitive Data Types and Literals
Bits, Bytes, Bitwise and Shift Operations
Managing Bit Strings in Byte Arrays
►Reference Data Types and Variables
Reference Types Supported in Java
Class Type Variables Storing References
Explicit and Implicit Type Casting
Type Casting Compile and Runtime Error
StringBuffer - The String Buffer Class
System Properties and Runtime Object Methods
Generic Classes and Parameterized Types
Generic Methods and Type Inference
Lambda Expressions and Method References
Java Modules - Java Package Aggregation
Execution Threads and Multi-Threading Java Programs
ThreadGroup Class and "system" ThreadGroup Tree
Synchronization Technique and Synchronized Code Blocks
Deadlock Condition Example Programs
Garbage Collection and the gc() Method
Assert Statements and -ea" Option