后端json转对象,json转对象 java

json转对象，就是把json串用对象类表示，然后调用new JSONObject().parseObject(json, User.class)方法
如：json串

{ "id": "10", "name": "每特教育", "items": [ { "itemId": "20", "itemName": "蚂蚁课堂" }, { "itemId": "21", "itemName": "每特学院" } ]}

定义user类，将对象关系包含进去

package com.edu.emple;import java.util.List;/** * @author shkstart * @date 2019/6/10- 20:23 */class Item{ private String itemId; private String itemName; public String getItemId() { return itemId; } public void setItemId(String itemId) { this.itemId = itemId; } public String getItemName() { return itemName; } public void setItemName(String itemName) { this.itemName = itemName; } @Override public String toString() { return "Item{" + "itemId='" + itemId + ''' + ", itemName='" + itemName + ''' + '}'; }}public class User { private String id; private String name; private List<Item> items; public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public List<Item> getItems() { return items; } public void setItems(List<Item> items) { this.items = items; } @Override public String toString() { return "User{" + "id='" + id + ''' + ", name='" + name + ''' + ", items=" + items + '}'; }}

测试：

package com.edu.emple;import com.alibaba.fastjson.JSONArray;import com.alibaba.fastjson.JSONObject;/** * @author shkstart * @date 2019/6/10- 18:53 */public class test001 { static String json ="{"id":"10","name":"每特教育","items":[{"itemId":"20","itemName":"蚂蚁课堂"},{"itemId":"21","itemName":"每特学院"}]}"; public static void main(String[] args) { //1.先转换为jsonobject对象 JSONObject jsonObject = new JSONObject().parseObject(json); String id = jsonObject.getString("id"); System.out.println(id); String name = jsonObject.getString("name"); System.out.println("id:"+id+"name:"+name); JSONArray jsonArray =jsonObject.getJSONArray("items"); for (int i = 0; i < jsonArray.size(); i++) { JSONObject jsonObject1 = jsonArray.getJSONObject(i); String itemId = jsonObject1.getString("itemId"); String itemName = jsonObject1.getString("itemName"); System.out.println("itemId："+itemId+"----itemName"+itemName); } //json转对象 User user = new JSONObject().parseObject(json, User.class); System.out.println(user.toString()); }}

结果：