java内部类原理与用法详解

public class StaticOuter {
    private static int shared = 100;
    public static class StaticInner{
        public void staticInnerMethod() {
            System.out.println("Static Inner Method" + shared);
        }
    }
    StaticInner si1 = new StaticInner();
    public void test() {
        StaticInner si = new StaticInner();
        si.staticInnerMethod();
    }
    public static void main(String[] args) {
        StaticOuter so = new StaticOuter();
        so.test();
    //在外部类范围内
        StaticInner si1 = new StaticInner();
        si1.staticInnerMethod();
    //合法
    StaticOuter.StaticInner si2 = new StaticOuter.StaticInner();
        si2.staticInnerMethod();
    }
}
//在外部类范围外
class Test{
    StaticOuter.StaticInner si2 = new StaticOuter.StaticInner();
}

public class OriginalClass {
    private static int t1 = 100;
    private int t2 = 200;
    class OriginalInner{
        public void test() {
      /*
           * 不合法的表示，在成员内部类中不可以定义静态的变量和方法
          public static int inner = 100;
          public static void print() {
          }
          */
          //合法的final变量
          public static final int inner1 = 300;
            System.out.println("OriginalInner:"+ t1);//直接访问外部类静态变量
            System.out.println("OriginalInner:"+ t2);//直接访问外部类成员变量
            action();//直接访问外部类方法
            System.out.println("OriginalInner:"+ OriginalClass.this.t1);//
            System.out.println("OriginalInner:"+ OriginalClass.this.t2);
            OriginalClass.this.action();
        }
    }
    public void action() {
        System.out.println("originalinner action");
    }
    public static void main(String[] args) {
    //new一个内部类
        OriginalClass oc = new OriginalClass();
        OriginalInner oi = oc.new OriginalInner();
        oi.test();
    }
}

public class FunctionOuter {
    private static int s= 100;
    private int s1 = 20;
    public void print(final int param) {
        final int in = 300;
        class FunctionInner{
            public void innertest() {
                System.out.println("FunctionInner：s="+s);
                System.out.println("FunctionInner：s1="+s1);
                System.out.println("FunctionInner：in"+ in);
                test();
            }
        }
        FunctionInner fi = new FunctionInner();
        fi.innertest();
        System.out.println("print:in"+in);
    }
    public void test() {
        System.out.println("FunctionOuter："+s);
    }
    public static void main(String[] args) {
        FunctionOuter fo = new FunctionOuter();
        fo.print(900);
    }
}

new 父类(参数列表){
  //匿名内部类实现部分
}

new 父接口(){
  //匿名内部类实现部分
}