Android-Java-封装

package android.java.oop03;

class Person {

    int age;

}

public class PottingDemo {

    public static void main(String[] args) {
        Person person = new Person();
        person.age = -200;

        System.out.println("年龄是:" + person.age);
    }

}

package android.java.oop03;

class Person {

    /**
     * 加入私有private，不对外暴露
     */
    private int age;

    public void setAge(int age) {

        if (age < 0 || age > 200) {
            throw new IllegalArgumentException("setAge age值不规范，age value:" + age);
        }

        this.age = age;
    }

    public int getAge() {
        return age;
    }
}

public class PottingDemo {

    public static void main(String[] args) {
        Person person = new Person();
        person.setAge(9);

        System.out.println("年龄是:" + person.getAge());
    }

}

package android.java.oop03;

class Counter {

    int add(int number1, int number2) {
       return number1 + number2;
    }


    int jian(int number1, int number2) {
        return number1 - number2;
    }


    int cheng(int number1, int number2) {
        return number1 * number2;
    }


    int chu(int number1, int number2) {
        return number1 / number2;
    }

    void doCounter(int number1, String f, int number2) {

        int result;

        if ("+".equals(f)) {
            result = add(number1, number2);
        } else if ("-".equals(f)) {
            result = jian(number1, number2);
        } else if ("*".equals(f)) {
            result = cheng(number1, number2);
        } else if ("/".equals(f)) {
            result = chu(number1, number2);
        } else {
            throw new IllegalArgumentException("传入的运算符 有异常，不能是 f" + f);
        }

        println(result);
    }

    void println(int result) {
        System.out.println("运算的结果是：" + result);
    }
}

public class PottingDemo2 {

    public static void main(String[] args) {
        Counter counter = new Counter();
        counter.doCounter(8, "+" ,8);
        counter.doCounter(20,"-", 10);
        counter.doCounter(9, "*", 9);
        counter.doCounter(100,"/",2);
    }

}

package android.java.oop03;

class Counter {

    private int add(int number1, int number2) {
       return number1 + number2;
    }


    private int jian(int number1, int number2) {
        return number1 - number2;
    }


    private int cheng(int number1, int number2) {
        return number1 * number2;
    }


    private int chu(int number1, int number2) {
        return number1 / number2;
    }

    public void doCounter(int number1, String f, int number2) {

        int result;

        if ("+".equals(f)) {
            result = add(number1, number2);
        } else if ("-".equals(f)) {
            result = jian(number1, number2);
        } else if ("*".equals(f)) {
            result = cheng(number1, number2);
        } else if ("/".equals(f)) {
            result = chu(number1, number2);
        } else {
            throw new IllegalArgumentException("传入的运算符 有异常，不能是 f" + f);
        }

        println(result);
    }

    private void println(int result) {
        System.out.println("运算的结果是：" + result);
    }
}

public class PottingDemo2 {

    public static void main(String[] args) {
        Counter counter = new Counter();
        counter.doCounter(8, "+" ,8);
        counter.doCounter(20,"-", 10);
        counter.doCounter(9, "*", 9);
        counter.doCounter(100,"/",2);
    }

}