Java in a Nutshell, 5th Edition

Name

Class<T>

Synopsis

This class represents a Java type. There is one Class object for each class that is loaded into the Java Virtual Machine, and, as of Java 1.1, there are special Class objects that represent the Java primitive types. The TYPE constants defined by Boolean, Integer, and the other primitive wrapper classes hold these special Class objects. Array types are also represented by Class objects in Java 1.1.

There is no constructor for this class. You can obtain a Class object by calling the getClass( ) method of any instance of the desired class. In Java 1.1 and later, you can also refer to a Class object by appending .class to the name of a class. Finally, and most interestingly, a class can be dynamically loaded by passing its fully qualified name (i.e., package name plus class name) to the static Class.forName( ) method. This method loads the named class (if it is not already loaded) into the Java interpreter and returns a Class object for it. Classes can also be loaded with a ClassLoader object.

The newInstance( ) method creates an instance of a given class; this allows you to create instances of dynamically loaded classes for which you cannot use the new keyword. Note that this method works only when the target class has a no-argument constructor. See newInstance( ) in java.lang.reflect.Constructor for a more powerful way to instantiate dynamically loaded classes. In Java 5.0, Class is a generic type and the type variable T specifies the type that is returned ...