1:类的属性一般设置为private getter 添加一个方法，用来读取属性的值 setter 添加一个方法，用来设置属性的值 例子 hello的主函数：
package my; public class Hello { public static void main(String[] args) { Example ex=new Example(); ex.setNumber(123); System.out.println("the result:"+ex.getNumber()); } } /*the result:123 Process finished with exit code 0 */Example 类
package my; public class Example { public int number; public String name; public int getNumber() { return this.number; } public void setNumber(int number) { this.number = number; } }