Java 反射的使用

package com.justbon.bestsign.common.contract.client;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
public class Test {

    public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, NoSuchMethodException {
        Class<?> cat = Class.forName("com.justbon.bestsign.common.contract.client.cat");
        cat OBJ = (com.justbon.bestsign.common.contract.client.cat) cat.newInstance();
        Field[] fields = cat.getFields();
        for (Field f : fields) {
            if (f.getName().equals("arrayListoo")) {
                try {
                    // ======
                    List arr=new ArrayList<String>();
                    Method method01 =  arr.getClass().getMethod("add", Object.class);
                    method01.invoke(arr,"123456");
                    arr.forEach(e->{
                        System.out.println(e.toString());
                    });
                    // 这里的f.getClass()就是cat来里面的arrayListoo，但是添加会报错
                    Class<? extends Field> aClass = f.getClass();
                    Class<?> type = f.getType();

                    Method method = type.getMethod("add",  Object.class);
                    method.invoke(OBJ.arrayListoo, "123456");
                    OBJ.arrayListoo.forEach(e -> {
                        System.out.println("======================");
                        System.out.println(e);
                    });


                } catch (InvocationTargetException e) {
                    e.printStackTrace();
                }

            }

        }
    }
}


package com.fanshe;
import java.util.ArrayList;
import java.util.List;
public class cat {
    public   List  arrayListoo=new ArrayList<String>();
    public void   getcat(){
        arrayListoo.add("1");
    }
}