java反射机制最详解

		Person p = new Person();
		//获取class对象的方式1
		// 需要依赖
		Class clazz = p.getClass();
		// 方式2 在编译之前就知道要操作的class的名称是什么
		Class clacc = Person.class;
Class clazz = Class.forName("com.openlab.test.Person");
		Constructor[] con = clazz.getConstructors();
		Method[] methods = clazz.getDeclaredMethods();
		Field[] fields = clazz.getDeclaredFields();
		System.out.println(con.length);
		System.out.println(methods.length);
		System.out.println(fields.length);

package com.openlab.test;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class Test {
	public static void main(String[] args) {
//		Person p = new Person();
//		//获取class对象的方式1
//		// 需要依赖
//		Class clazz = p.getClass();
//		// 方式2 在编译之前就知道要操作的class的名称是什么
//		Class clacc = Person.class;
//		
//		Constructor[] con = clazz.getConstructors();
//		Method[] methods = clazz.getDeclaredMethods();
//		Field[] fields = clazz.getDeclaredFields();
//		
//		System.out.println(con.length);
//		System.out.println(methods.length);
//		System.out.println(fields.length);
		// 方式3 常用
		Class clazz;
		try {
			clazz = Class.forName("com.openlab.test.Person");
			Constructor con = clazz.getDeclaredConstructor(new Class[]{String.class,int.class});
			con.setAccessible(true);
			Person p = (Person) con.newInstance(new Object[]{"张三疯",99});
			System.out.println(p);
			
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (NoSuchMethodException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SecurityException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (InstantiationException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (InvocationTargetException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
//		Person p = (Person) clazz.newInstance();
	}
}