Java反射創(chuàng)建實(shí)例

package com.wkcto.chapter08.demo02;

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

/**
 * 通過反射創(chuàng)建對(duì)象(創(chuàng)建實(shí)例)
 * 		newInstance()
 * 
 * @author 蛙課網(wǎng)
 *
 */
public class Test01 {

	public static void main(String[] args) throws InstantiationException, IllegalAccessException, NoSuchMethodException, SecurityException, IllegalArgumentException, InvocationTargetException {
		//1) 創(chuàng)建Class對(duì)象
		Class<?> class1 = Person.class;
		
		//2) 直接通過Class對(duì)象創(chuàng)建實(shí)例,會(huì)調(diào)用類的無參構(gòu)造方法,如果沒有無參構(gòu)造,則實(shí)例化異常
		Object obj1 = class1.newInstance();
		System.out.println( obj1 );  	//調(diào)用對(duì)象的toString()	
		
		//3)通過構(gòu)造方法創(chuàng)建實(shí)例
		//3.1 反射構(gòu)造方法Person(String, int, String)
		Constructor<?> constructor = class1.getConstructor(String.class, int.class, String.class);
		
		//3.2通過構(gòu)造方法 創(chuàng)建實(shí)例, 調(diào)用newInstance()方法,傳遞構(gòu)造方法的實(shí)參
		Object obj2 = constructor.newInstance("lisi", 18,"男");    //new Person("lisi", 18,"男")
		System.out.println( obj2 );
		
		
	}

}

package com.wkcto.chapter08.demo02;

public class Person {
	public String name;
	int age;
	private String gender;
	static String country = "中國(guó)";
	
	public Person() {
		System.out.println("Person類的無參構(gòu)造方法");
	}

	public Person(String name, int age, String gender) {
		System.out.println("Person類的有三個(gè)參數(shù)的構(gòu)造方法");
		this.name = name;
		this.age = age;
		this.gender = gender;
	}
	
	public void set(String name, int age, String gender) {
		this.name = name;
		this.age = age;
		this.gender = gender;
	}

	@Override
	public String toString() {
		return "Person [name=" + name + ", age=" + age + ", gender=" + gender + "]";
	}
		
}