java复杂对象转json字符串_java处理json数据

package test;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.google.common.collect.Lists;
import java.lang.reflect.Field;
import java.util.List;

/**
 * Created by memory_fu on 2021/1/7.
 */
public class ReflectasmTest {
    
    public static void main(String[] args) throws IllegalAccessException {
        Person person = new Person();
        person.setAge(10);
        person.setId("1");
        person.setName("傅浩");
        person.setHobby("ball");
        
        int sumCount = 20000000;// 循环次数
        
        long l1 = System.currentTimeMillis();
        for (int i = 0; i < sumCount; i++) {
            testFastJSON(person);
        }
        System.out.println("fastjson方式转换=====: " + (System.currentTimeMillis() - l1) + " ms.");
        
        long l2 = System.currentTimeMillis();
        for (int i = 0; i < sumCount; i++) {
            testReflection(person);
        }
        System.out.println("JAVA反射方式转换=====: " + (System.currentTimeMillis() - l2) + " ms.");
        
    }
    
    /**
     * 方式一:
     * fastjson 对象转为JSON字符串
     */
    public static <T> void testFastJSON(T vo) throws IllegalAccessException {
        String string = JSON.toJSONString(vo);
        JSONObject jsonObject = JSON.parseObject(string);
        String str = jsonObject.toJSONString();
//        System.out.println(str);
    }
    
    public static List<Field> fields = null;
    
    /**
     * 反射方式拿到类的field集合
     */
    public static <T> List<Field> init(T vo) {
        Class<?> aClass = vo.getClass();
        fields = Lists.newArrayList();
        for (Class i = aClass; i != Object.class; i = i.getSuperclass()) {
            Field[] declaredFields = i.getDeclaredFields();
            for (Field field : declaredFields) {
                fields.add(field);
            }
        }
        return fields;
    }
    
    /**
     * 方式二:
     * 反射方式  对象转为JSON字符串
     */
    public static <T> void testReflection(T vo) throws IllegalAccessException {
        if (fields == null) {
            init(vo);
        }
        
        JSONObject jsonObject = new JSONObject();
        for (Field field : fields) {
            jsonObject.put(field.getName(), field.get(vo));
        }
        String str = jsonObject.toJSONString();
//        System.out.println(str);
    }
    
}