class Person{

    private String name ;

    private String sex ;

    public  Person(){

        System.out.println("c");

    }

    public  Person(String c1){

         this.name =c1;

        System.out.println("c1"+c1);

    }

    public  Person(String c1,String c2){

        this.name =c1;

        this.sex =c2;

        System.out.println("c1"+c1 +"c2"+c2);

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getSex() {

        return sex;

    }

    public void setSex(String sex) {

        this.sex = sex;

    }

}    

 public  static  void  main(String [] args){

        try {

            Class<?> clazz = Class.forName("com.leeeason.miaosha.Person") ; // 取得Class对象

            Constructor<?>[] constructors = clazz.getConstructors();

            System.out.print(constructors.length);

            Object o = constructors[0].newInstance();

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

  public  static  void  main(String [] args){

        try {

            Class<?> clazz = Class.forName("com.leeeason.miaosha.Person") ; // 取得Class对象

            Constructor<?>[] constructors = clazz.getConstructors();

            //System.out.print(constructors.length);

            //修改后

            Object o = constructors[2].newInstance();

        } catch (Exception e) {

            e.printStackTrace();

        }

    }