Reflection反射机制

import com.sun.jdi.InvocationException;

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

public class TestReflection {
    public TestReflection(){
         type = 1;
    }
    public TestReflection(Integer t){
        type = t;
    }
    private  Integer type;

    public Integer plus(Integer num1,Integer num2) {
        return num1 + num2;
    }

    public Integer minus(Integer num1,Integer num2) {
        return num1 - num2;
    }

    public static void main(String[] args) throws ClassNotFoundException,NoSuchMethodException,InstantiationException,IllegalAccessException, InvocationTargetException {
        //根据类全限定名称获取class类型
        Class myTest  = Class.forName("TestReflection");
        System.out.println(myTest.getName());
        //遍历构造函数
        Constructor[] constructors = myTest.getConstructors();
        for(Constructor con : constructors){
            System.out.println(con.toString());
        }
        //遍历所有方法
        Method[] methods = myTest.getDeclaredMethods();
        for(Method method:methods){
            System.out.println(method.toString());
        }
        //遍历所有字段
        Field[] fields = myTest.getDeclaredFields();
        for(Field field : fields){
            System.out.println("字段："+field.getName());
        }
        //实例化对象，执行方法
        Object obj = myTest.getConstructor().newInstance();
        Method plus1 = myTest.getDeclaredMethod("plus", Integer.class, Integer.class);
        Method minus1 = myTest.getDeclaredMethod("minus", Integer.class, Integer.class);
        Object plusResult = plus1.invoke(obj,5,3);
        System.out.println(plusResult);

        Object minsResult = minus1.invoke(obj,6,2);
        System.out.println(minsResult);

    }

    }