定义一个类
package com.zx;
 public class NotebookComputer {
     private int num;    
     private CPU cpu;
     public String fromIntoBit(){    
         class CPU2{// 局部内部类
             public String countBit(int num){
                 return Integer.toBinaryString(num);
             }
         }
         return (new CPU2().countBit(num));
     }
     /***
      * 普通内部类
      */
 private final class CPU{
         
         }
     public NotebookComputer(int num){
         this.num = num;
         if(cpu == null)
             cpu = new CPU();
     }
     
 }
 定义测试类package com.zx;
  
 public class TestInnerClass {
     public static void main(String[] args) {
 //        // 创建一个外部类
 //        NotebookComputer com = new NotebookComputer();
 //        // 声明一个内部类
 //        NotebookComputer.CPU cpu;
 //        
 //        // 通过外部类的实例创建一个内部类对象
 //        cpu = com.new CPU();
 //        
 //        String bitStr = cpu.countBit(11);
 //        System.out.println(bitStr);
         NotebookComputer com = new NotebookComputer(9);
         
         System.out.println(com.fromIntoBit());
         
 //        System.out.println(com.fromIntoBit());
 //        
 //        /* 内部静态类的创建*/
 //        NotebookComputer.VideoCard vc = new NotebookComputer.VideoCard();
 //        
 //        vc.showMessage("我是内部静态类");
         
     }
 }


运行结果

java66-局部类内方法访问_ide