public void aMethod() {
theButton.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("The action has occure");
}
}
);
}
클래스끝에 세미콜론이 있어야 한다는 점과 메소드안에서 선언된 변수를 참조하려면 final 이어야 함을 기억하자.public java.util.Enumeration enumerate() { // The anonymous class is defined as part of the return statementreturn new java.util.Enumeration() { Linkable current; = head; { current = head; } // Replace constructor with an instance initializer public boolean hasMoreElements() { return (current != null); } public Object nextElement() { if (current == null) throw new java.util.NoSuchElementException(); Object value = current; current = current.getNext(); return value; } }; // Note the required semicolon: it terminates the return statement}
Why use anonymous classes?
As with local classes, objects instantiated from anonymous classes
share many of the characteristics of objects instantiated from member
classes. However, in some cases, an anonymous class can be
defined closer to its point of use than would be possible with a member
class or a local class. Once
you become accustomed to the somewhat cryptic syntax used with
anonymous
classes, this can often lead to improved code readability.
Probably the most important benefit of anonymous classes has to do
with accessing the members of enclosing classes. Just like with
member classes and local classes, methods of an anonymous class have
direct access
to all the members of the enclosing classes, including private
members.
Thus the use of anonymous classes can often eliminate the requirement
to connect objects together via constructor parameters.
In addition, although not demonstrated in this lesson, as with local
classes, objects of anonymous classes have access to final
local variables that are declared within the scope of the anonymous
class.
An anonymous class can be particularly useful in those cases where
- There is no reason for an object of the anonymous class to exist in the absence of an object of the enclosing class.
- There is no reason for an object of the anonymous class to exist outside a method of the enclosing class.
- Methods of the object of the anonymous class need access to members of the object of the enclosing class.
- Methods of the object of the anonymous class need access to final local variables and method parameters belonging to the method in which the anonymous class is defined.
- Only one instance of the anonymous class is needed.
- There is no need for the class to have a name that is accessible elsewhere in the program.
Anonymous Class 초기화 하기 - Instance initializer
http://www.javastudy.co.kr/docs/b612/basic/doc/study5.html
http://www.unix.org.ua/orelly/java-ent/jnut/ch03_12.htm
http://www.developer.com/java/other/article.php/3300881
