转载：如何把java对象转换为json java对象怎么转成json_clghxq的技术博客_51CTO博客
Java对象列表转换为JSON对象数组，并转为字符串
JSONArray jsonArray = JSONArray.fromObject(list);
String jsonArrayStr = jsonArray.toString();
2、把Java对象转换成JSON对象，并转化为字符串
JSONObject jsonObject = JSONObject.fromObject(obj);
String jsonObjectStr = jsonObject.toString();
3、过滤不需要转换为JSON格式的属性
使用jsonConfig对象的setExcludes()方法，传入参数为待过滤属性组成的数组。
JsonConfig cfg = new JsonConfig();
cfg.setExcludes(new String[] {“待过滤属性1”, “待过滤属性2”, ..., “待过滤属性n”});
json转bean
JSONObject.toBean(targetJson, targetClass);实例
package com.ajax.test;
import java.util.ArrayList;
import java.util.List;
import com.fasterxml.jackson.core.JsonProcessingException;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.JsonConfig;
public class Customer {
public Customer(String name, String id) {
super();
this.name = name;
this.id = id;
}
private String name;
private String id;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public static void main(String[] args) throws JsonProcessingException {
//包含多个对象的List集合转换为JSON格式
List
Customer c1 = new Customer("Alice", "001");
Customer c2 = new Customer("Bruce", "002");
Customer c3 = new Customer("Cindy", "003");
list.add(c1);
list.add(c2);
list.add(c3);
JsonConfig config1 = new JsonConfig();
//过滤List集合中的Customer对象的id属性不生成JSON
config1.setExcludes(new String[] {"id"});
JSONArray jsonArray = JSONArray.fromObject(list, config1);
System.out.println(jsonArray.toString());
//一个对象转换为JSON格式
Customer c = new Customer("Boss", "004");
JsonConfig config2 = new JsonConfig();
//过滤Customer对象的id属性不生成JSON
config2.setExcludes(new String[] {"id"});
JSONObject jsonObject = JSONObject.fromObject(c, config2);
System.out.println(jsonObject.toString());
}
}
将父类对象转化为子类对象：
创建父类实例，将父类实例化
将子类实例转化成json
将父类实例转化成json
遍历父类json实例，使用子类json获取vaule值，设置到父类json中。
代码如下：
public static Object createBeanWith(Class targetClass, Object source) { Object target = null; try { target = targetClass.newInstance(); } catch (Exception e) { return null; } JSONObject targetJson = JSONObject.fromObject(target); JSONObject sourceJson = JSONObject.fromObject(source); for (Object key : targetJson.keySet()) { if (sourceJson.containsKey(key)) { targetJson.put(key, sourceJson.get(key)); } } return JSONObject.toBean(targetJson, targetClass); }精简写法：
Object result = JSONObject.parseObject(JSONObject.toJSONString(source), targetClass);maven依赖的包：
net.sf.json-lib json-lib 2.4 jdk15 org.json json 20230227 net.sf.ezmorph ezmorph 1.0.6 commons-beanutils commons-beanutils 1.9.4 commons-collections commons-collections 3.2.2 org.apache.commons commons-lang3 3.4 commons-lang commons-lang 2.6 commons-logging commons-logging 1.2 commons-io commons-io 2.4 使用hutool工具类
import cn.hutool.json.JSONObject;import cn.hutool.json.JSONUtil;public static Object createBeanWith(Class targetClass, Object source) { Object target = null; try { target = targetClass.newInstance(); } catch (Exception e) { return null; } JSONObject targetJson = JSONUtil.parseObj(target, false); JSONObject sourceJson = JSONUtil.parseObj(source, false); for (String key : targetJson.keySet()) { if (sourceJson.containsKey(key)) { targetJson.set(key, sourceJson.get(key)); } } return JSONUtil.toBean(targetJson, targetClass); }使用Spring类的方法：
Foo foo = new Foo();Son son = new Son();BeanUtils.copyProperties(foo, son);参考：
父类转换成子类， 或者是类之间属性拷贝_父类对象转换为子类对象_孔先生在吗的博客-CSDN博客
来源地址：https://blog.csdn.net/u200814342A/article/details/132291033
