1、fastjson运用

0、JSON使用阿里的 fastJson 为依赖包

1、String转JSONObject

JSONObject jSONObject = JSONObject.parseObject(String);

2、String转JSONArray

JSONArray jsonArray= JSONArray.parseArray(String);

3、实例

json串：

{
    "data": {
        "route": {
            "destination": "109.56350818276404,39.575900296924715",
            "paths": [{
                    "distance": 200067,
                    "steps": [{
                            "action": "右转",
                            "assistant_action": "",
                            "cities": [{
                                    "adcode": "610802"
                                }, {
                                    "adcode": "610802"
                                }
                            ]
                        }, {
                            "action": "左转",
                            "assistant_action": "",
                            "cities": [{
                                    "adcode": "610802"
                                }, {
                                    "adcode": "610802"
                                }
                            ]
                        }
                    ],
                    "strategy": "时间最短"
                }
            ]
        },
        "count": 1
    },
    "errmsg": "OK"
}

　　

解析代码：

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;

/**
 * @Date 2021/8/13 11:15
 * @Version 1.0
 */
public class TestJsonParse {
    public static void main(String[] args) {
        String jsonStr = "{" +
                "    "errmsg": "OK"," +
                "    "data": {" +
                "        "route": {" +
                "            "destination": "109.56350818276404,39.575900296924715"," +
                "            "paths": [{" +
                "                    "distance": 200067," +
                "                    "steps": [{" +
                "                            "action": "右转"," +
                "                            "assistant_action": ""," +
                "                            "cities": [{" +
                "                                    "adcode": "610802"" +
                "                                }, {" +
                "                                    "adcode": "610802"" +
                "                                }" +
                "                            ]" +
                "                        }, {" +
                "                            "action": "左转"," +
                "                            "assistant_action": ""," +
                "                            "cities": [{" +
                "                                    "adcode": "610802"" +
                "                                }, {" +
                "                                    "adcode": "610802"" +
                "                                }" +
                "                            ]" +
                "                        }" +
                "                    ]," +
                "                    "strategy": "时间最短"" +
                "                }" +
                "            ]" +
                "        }," +
                "        "count": 1" +
                "    }" +
                "}";

        // 第一层
        JSONObject one = JSONObject.parseObject(jsonStr);
        System.out.println("data: " + one.get("errmsg").toString());
        // 第二层
        JSONObject two = JSON.parseObject( one.get("data").toString());
        // 第三层
        JSONObject three = JSON.parseObject( two.get("route").toString());
        // 第四层 数组
        JSONArray four = JSON.parseArray( three.get("paths").toString());
        // 第五层 获取数组中，第一个对象
        JSONObject five = four.getJSONObject(0);
        System.out.println("distance: " + five.get("distance"));
    }
}