p;action.doAction();
//define a nonoymous class which extends BaseClass and create an instance of it
new BaseClass(5) {
public void printData(){
System.out.println("data = " + getData());
}
}.printData(); //"data = 5" will be outputed
}
}
interface Action {
void doAction();
}
class BaseClass {
private int data;
public BaseClass (int data) {
this.data = data;
}
public int getData() {
return data;
}
}
4.1 匿名类特性与约束 匿名类是一种特殊的局部类。局部类的特性与约束都适用与它。 4.2 新增语法 4.2.1 继承自某个基类的匿名类
new class-name ( [ argument-list ] ) { class-body } 创建匿名类实例时，“argument-list”将被传入其基类（即class-name）对应的构造函数。 4.2.2 实现某个接口的匿名类 new interface-name () { class-body }
4.3 什么时候使用匿名类
该类定义代码段很短
只需要创建该类的一个实例
类的定义代码与类的使用代码紧邻
使用匿名不影响代码的易读性 譬如，如下实现类似与c的callback功能的代码就是匿名类的典型应用： File f = new File("/src"); // The directory to list
// Now call the list() method with a single FilenameFilter argument
// Define and instantiate an anonymous implementation of FilenameFilter
// as part of the method invocation expression.
String[] filelist = f.list(new FilenameFilter() {
public boolean accept(File f, String s) { return s.endsWith(".java"); }
}); // Don't forget the parenthesis and semicolon that end the method call上一页 [1] [2] [3] [4] [5] [6] [7]
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