JAVA使用GSON解析JSON数据

JAVA使用GSON解析JSON数据

在使用第三方api的使用,有时候会从网络中获得json数据,所以说我们将如何解析json数据?

下面小编将通过以下几点来进行json的讲解

1.什么是JSON? (http://www.json.org/)

JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999. JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language.

JAVA使用GSON解析JSON数据_第1张图片

2.Json数据类型

2-1.json对象

JAVA使用GSON解析JSON数据_第2张图片

ps:JSONObject与JSONArray的区别

JAVA使用GSON解析JSON数据_第3张图片

(JSON数组)

JAVA使用GSON解析JSON数据_第4张图片

(JSON数组)

3.解析JSON数据(小编使用的GSON进行json数据的解析)

3-1 【JSONObject的解析】

下面是一个json文件

{
    "resultcode": "200",
    "reason": "successed!",
    "result": {
        "sk": {
            "temp": "24",
            "wind_direction": "西南风",
            "wind_strength": "2级",
            "humidity": "51%",
            "time": "10:11"
        },
        "today": {
            "temperature": "16℃~27℃",
            "weather": "阴转多云",
            "weather_id": {
                "fa": "02",
                "fb": "01"
            },
            "wind": "西南风3-4 级",
            "week": "星期四",
            "city": "滨州",
            "date_y": "2015年06月04日",
            "dressing_index": "舒适",
            "dressing_advice": "建议着长袖T恤、衬衫加单裤等服装。年老体弱者宜着针织长袖衬衫、马甲和长裤。",
            "uv_index": "最弱",
            "comfort_index": "",
            "wash_index": "较适宜",
            "travel_index": "",
            "exercise_index": "较适宜",
            "drying_index": ""
        },
        "future": [
            {
                "temperature": "16℃~27℃",
                "weather": "阴转多云",
                "weather_id": {
                    "fa": "02",
                    "fb": "01"
                },
                "wind": "西南风3-4 级",
                "week": "星期四",
                "date": "20150604"
            },
            {
                "temperature": "20℃~32℃",
                "weather": "多云转晴",
                "weather_id": {
                    "fa": "01",
                    "fb": "00"
                },
                "wind": "西风3-4 级",
                "week": "星期五",
                "date": "20150605"
            },
            {
                "temperature": "23℃~35℃",
                "weather": "多云转阴",
                "weather_id": {
                    "fa": "01",
                    "fb": "02"
                },
                "wind": "西南风3-4 级",
                "week": "星期六",
                "date": "20150606"
            },
            {
                "temperature": "20℃~33℃",
                "weather": "多云",
                "weather_id": {
                    "fa": "01",
                    "fb": "01"
                },
                "wind": "北风微风",
                "week": "星期日",
                "date": "20150607"
            },
            {
                "temperature": "22℃~34℃",
                "weather": "多云",
                "weather_id": {
                    "fa": "01",
                    "fb": "01"
                },
                "wind": "西南风3-4 级",
                "week": "星期一",
                "date": "20150608"
            },
            {
                "temperature": "22℃~33℃",
                "weather": "阴",
                "weather_id": {
                    "fa": "02",
                    "fb": "02"
                },
                "wind": "西南风3-4 级",
                "week": "星期二",
                "date": "20150609"
            },
            {
                "temperature": "22℃~33℃",
                "weather": "多云",
                "weather_id": {
                    "fa": "01",
                    "fb": "01"
                },
                "wind": "南风3-4 级",
                "week": "星期三",
                "date": "20150610"
            }
        ]
    },
    "error_code": 0
}

我们进行解析(解析一部分)

package cn.edu.bzu.json;
 
import java.io.FileNotFoundException;
import java.io.FileReader;
 
import com.google.gson.JsonArray;
import com.google.gson.JsonIOException;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.JsonSyntaxException;
 
public class Read {
    public static void main(String args[]){
        JsonParser parse =new JsonParser();  //创建json解析器
        try {
            JsonObject json=(JsonObject) parse.parse(new FileReader("weather.json"));  //创建jsonObject对象
            System.out.println("resultcode:"+json.get("resultcode").getAsInt());  //将json数据转为为int型的数据
            System.out.println("reason:"+json.get("reason").getAsString());     //将json数据转为为String型的数据
             
            JsonObject result=json.get("result").getAsJsonObject();
            JsonObject today=result.get("today").getAsJsonObject();
            System.out.println("temperature:"+today.get("temperature").getAsString());
            System.out.println("weather:"+today.get("weather").getAsString());
             
        } catch (JsonIOException e) {
            e.printStackTrace();
        } catch (JsonSyntaxException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
}

输出结果:


3-2 【JSONArray的解析】

下面是一个json文件

{
    "cat":"it",
    "language":[
        {"id":1,"ide":"eclipse","name":Java},
        {"id":2,"ide":"XCode","name":"Swift"},
        {"id":3,"ide":"Visual Stdio","name":"C#"}     
    ],
    "pop":true
}

我们进行解析:

package cn.edu.bzu.json;
 
import java.io.FileNotFoundException;
import java.io.FileReader;
 
import com.google.gson.JsonArray;
import com.google.gson.JsonIOException;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.JsonSyntaxException;
 
public class ReadJSON {
    public static void main(String args[]){
        try {
             
            JsonParser parser=new JsonParser();  //创建JSON解析器
            JsonObject object=(JsonObject) parser.parse(new FileReader("test.json"));  //创建JsonObject对象
            System.out.println("cat="+object.get("cat").getAsString()); //将json数据转为为String型的数据
            System.out.println("pop="+object.get("pop").getAsBoolean()); //将json数据转为为boolean型的数据
             
            JsonArray array=object.get("language").getAsJsonArray();    //得到为json的数组
            for(int i=0;i

输出结果:


JAVA使用GSON解析JSON数据_第5张图片

3-3 【分析】

我们通过Gson进行解析,所以在使用前需要导入Gson.jar

解析json数据时,

1.需要进行创建Gson解析器

2.创建JSONObject对象

3.将json数据转为为相应的数据
ps:maven依赖:https://mvnrepository.com/

第三方api之解析bmob的json

 private static void Search() {
        BSONObject where1 = new BSONObject(Where.less(10));
        BSONObject where = new BSONObject();
        String result = Bmob.find("VideoInfo", where.toString(), 0, 50, "order");
        System.out.println(result);
        JsonParser parser=new JsonParser();  //创建JSON解析器
        try {
            JsonObject object=(JsonObject) parser.parse(result);
            JsonArray jsonArray = object.getAsJsonArray("results");
            for (int i=0;i

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