Java 反射 调用 demo

package fanshe;

public class Person {
public String name;
private String age;
private int p;
public Person() {};
public Person(String name, String age) {
super();
this.name = name;
this.age = age;
}
private Person(String name, String age,int p) {
super();
this.name = name;
this.age = age;
this.p = p;
}
public String getName() {
return name;
}
@Override
public String toString() {
return "Person [name=" + name + ", age=" + age + "]" + "p -"+ p;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
}

package fanshe;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class demo1 {

public static void main(String[] args) {
// TODO Auto-generated method stub
try {
d_3();
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}

private static void d_1() {
Person p = new Person();
Class  c = p.getClass();

}

private static void d_2() {
Class  c =  Person.class;
System.out.println(c);
}
private static void d_3() throws ClassNotFoundException, NoSuchMethodException, SecurityException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchFieldException {
Class  c = Class.forName("fanshe.Person");

//--------------------------//
Constructor con = c.getConstructor(); //获得 空参数的构造器 public
Object o= con.newInstance(); //运行获取到的构造方法
System.out.println(o.toString());

//--------------------------//
Constructor con2 = c.getConstructor(String.class,String.class); //获得带有参数的构造方法 public
Object o2 = (Person)con2.newInstance("a","22");
System.out.println(o2.toString());

//--------------------------//

Constructor con3 = c.getDeclaredConstructor(String.class,String.class,int.class); //获得带有参数的构造方法 private
con3.setAccessible(true);
Object o3 = (Person)con3.newInstance("a","22",14);
System.out.println(o3.toString());

//--------------------------//
Object tmp_obj = c.newInstance();
Field f_name = c.getField("name");//获得成员变量 public
f_name.set(tmp_obj, "abc"); //设置变量
System.out.println(tmp_obj);

//--------------------------//
Field f_age = c.getDeclaredField("age");//获得成员变量 public
System.out.println(f_age);

//--------------------------//
Method m_getName = c.getMethod("getName"); //获得类函数无参数 public
Object o1 = m_getName.invoke(tmp_obj); //运行getName方法.返回值 反给obj
System.out.println(o1);

//--------------------------//
Method m_setName = c.getMethod("setName",String.class);
m_setName.invoke(tmp_obj,"abcdqweqwe");
System.out.println(tmp_obj.toString());
}
}

ArrayList<String> arr = new ArrayList<String>();
arr.add("a");
Class carr = arr.getClass();
Method arr_add = carr.getMethod("add",Object.class);
arr_add.invoke(arr, 1);
arr_add.invoke(arr, 2);
arr_add.invoke(arr, 3);
arr_add.invoke(arr, 4);
System.out.println(arr);