【java开发系列】—— 嵌套类与内部类

1 class out1{
2     private static String name = "xingoo";
3     static class info{
4         void print(){
5             System.out.println("name："+name);
6         }
7     }
8 }

package testClass;
class out1{
    private static String name = "xingoo";
    static class info{
        void print(){
            System.out.println("name："+name);
        }
    }
}
class out2{
    private static String name = "xingoo test 2";
    static class info{
        String name = "inner infomation!";
        void printInner(){
            System.out.println("name:"+name);
        }
        void printOuter(){
            System.out.println("name:"+out2.name);
        }
    }
}
/**
 * 静态嵌套类
 * @author xingoo
 *
 */
public class test1 {
    public static void main(String[] args){
        //创建对象时，以xxx.yyy这种格式创建
        out1.info oi = new out1.info();
        oi.print();
        
        out2.info oi2 = new out2.info();
        oi2.printInner();
        oi2.printOuter();
    }
}

1 class outer{
2     private String name = "xingoo";
3     class inner{
4         void print(){
5             System.out.println(name);
6         }
7     }
8 }

 1 interface Printer{
 2     void print(String name);
 3 }
 4 class outerImpl1 implements Printer{
 5     @Override
 6     public void print(String name) {
 7         System.out.println(name);
 8     }
 9 }
10 class outerImpl2{
11     private class inner implements Printer{
12         @Override
13         public void print(String name) {
14             System.out.println(name);
15         }
16     }
17     public Printer getPrinter(){
18         return new inner();
19     }
20 }

package testClass;
/**
 * 简单测试成员内部类
 * @author xingoo
 *
 */
class outer{
    private String name = "xingoo";
    class inner{
        void print(){
            System.out.println(name);
        }
    }
}
interface Printer{
    void print(String name);
}
class outerImpl1 implements Printer{
    @Override
    public void print(String name) {
        System.out.println(name);
    }
}
class outerImpl2{
    private class inner implements Printer{
        @Override
        public void print(String name) {
            System.out.println(name);
        }
    }
    public Printer getPrinter(){
        return new inner();
    }
}
/**
 * 成员内部类
 * @author xingoo
 *
 */
public class test2 {
    public static void main(String[] args){
        //创建一个外部类的对象，通过调用这个对象的new方法创建其内部类的对象
        outer o = new outer();
        outer.inner i = o.new inner();
        i.print();
        
        
        //内部类实现接口隐藏
        Printer out1 = new outerImpl1();
        out1.print("xingoo test1");
        outerImpl1 out1trans = (outerImpl1)out1;//支持向下转换
        
        Printer out2 = (new outerImpl2()).getPrinter();
        out2.print("xingoo test2");
        //无法向下转换，因为inner是private类型的，这样就实现了接口的隐藏
    }
}

 1 interface Logger{
 2     public void log(String message);
 3 }
 4 public class test3 {
 5     
 6     String startTime = (new Date()).toString();
 7     /**
 8      * 局部内部类，从定义上来讲，不属于任何其他的类，因为是声明在这个类内部的。与匿名内部类不同的就是它有名字。
 9      * @return
10      */
11     public Logger getLogger(){
12         //由于LoggerImpl只在 getLogger内部使用，因此把它定义在函数内部，相对来说更安全一些
13         class LoggerImpl implements Logger{
14             @Override
15             public void log(String message) {
16                 System.out.println(startTime + ":" + message);
17             }
18         }
19         return new LoggerImpl();
20     }
21     
22     public static void main(String[] args){
23         test3 test = new test3();
24         Logger logger = test.getLogger();
25         logger.log("hello xingoo!");
26     }
27 }

 1 abstract class Printable{
 2     public void print(String name){
 3         
 4     }
 5 }
 6 /**
 7  * 就是跟在new创建对象之后，直接定义它的类实现
 8  * @author Administrator
 9  */
10 public class test4 {
11     public static void main(String[] args){
12         Printable printer = new Printable(){
13             public void print(String name){
14                 System.out.println(name);
15             }
16         };//注意因为这其实是一个new语法，因此要加上分号;
17         printer.print("hello!xingoo!");
18     }
19 }