局部内部类

package ch6;/** * Created by Jiqing on 2016/11/21. */public class LocalInnerClass { // 局部内部类    public static void main(String[] args) {        // 定义局部内部类        class InnerBase {            int a;        }        // 定义局部内部类的子类        class InnerSub extends InnerBase        {            int b;        }        // 创建局部内部类对象        InnerSub is = new InnerSub();        is.a = 5;        is.b = 10;        System.out.println("InnerSub对象的a和b实例变量是：" + is.a + "," + is.b);    }}

强制回收

package ch6;/** * Created by Jiqing on 2016/11/21. */public class Gc {    public static void main(String[] args) {        for(int i = 0; i<4;i++) {            new Gc();            // System.gc(); // 强制回收内存            Runtime.getRuntime().gc();        }    }    public void finalize() {        System.out.println("正在回收内存");    }}

抽象类与抽象函数

package ch6.Shape;/** * Created by Jiqing on 2016/11/21. */public abstract class Shape {    private String color;    public abstract double calPerimeter();    public abstract String getType();    public Shape() {}    public Shape(String color) {        System.out.println("执行Shape构造器...");        this.color = color;    }}

package ch6.Shape;/** * Created by Jiqing on 2016/11/21. */public class Triangle extends Shape {    private double a;    private double b;    private double c;    public Triangle(String color,double a,double b,double c){        super(color);        this.setSides(a,b,c);    }    public void setSides(double a,double b,double c){        if (a >= b + c || b >= a + c|| c >= a + b) {           System.out.println("三角形两边之和大于第三边...");           return;        }        this.a = a;        this.b = b;        this.c = c;    }    public double calPerimeter() {        return a + b + c;    }    public String getType() {        return "三角形";    }    public static void main(String[] args) {        Shape t = new Triangle("黑色",3,4,5);        System.out.println(t.calPerimeter());        System.out.println(t.getType());    }}

枚举类

package ch6.Enum;/** * Created by Jiqing on 2016/11/21. */public enum SeasonEnum { // 枚举类    SPRING,SUMMER,FALL,WINTER;}

package ch6.Enum;/** * Created by Jiqing on 2016/11/21. */public class Enum {    public void judge(SeasonEnum s) {        switch (s) {            case SPRING:                System.out.println("春暖花开,正好踏青");                break;            case SUMMER:                System.out.println("夏日炎炎，适合游泳");                break;            case FALL:                System.out.println("秋高气爽，进补及时");                break;            case WINTER:                System.out.println("冬天寒冷，被窝赏雪");        }    }    public static void main(String[] args) {        for (SeasonEnum s : SeasonEnum.values()) {            System.out.println(s);        }        new Enum().judge(SeasonEnum.FALL);    }}

package ch6.Enum;/** * Created by Jiqing on 2016/11/21. */public enum Operation { // 编译程序会生产5个class文件    PLUS{ // 匿名内部子类        public double eval(double x,double y) {            return x + y;        }    },    MINUS {        public double eval(double x,double y) {            return x - y;        }    },    TIMES {        public double eval(double x,double y) {            return  x * y;        }    },    DIVIDE {        public double eval(double x,double y) {            return x/y;        }    };    public abstract double eval(double x,double y);    public static void main(String[] args) {        System.out.println(Operation.DIVIDE.eval(1.2,2.3));    }}本文转自TBHacker博客园博客，原文链接：http://www.cnblogs.com/jiqing9006/p/6087610.html，如需转载请自行联系原作者