Java 使用gson 解析 Json

json数据

{
    "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
}

解析JSONObject

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.JsonSyntaxException;
import com.google.gson.JsonIOException;

import java.io.FileNotFoundException;
import java.io.FileReader;

public class ReadJson {
    public static void main(String []args) {
        JsonParser parse = new JsonParser();
        try {
            JsonObject json = (JsonObject) parse.parse(new FileReader("weather.json"));
            System.out.println("resultcode:" + json.get("resultcodeu").getAsInt());
            System.out.println("reason:" + json.get("reason").getAsString());
            JsonObject result = json.get("result").getAsJsonObject();
            JsonObject today = result.get("today").getAsJsonObject();
            System.out.println("weak:" + today.get("week").getAsString());
            System.out.println("weather:" + today.get("weather").getAsString());
        } catch (JsonIOException e) {
            e.printStackTrace();
        }  catch (NullPointerException e) {
            e.printStackTrace();
        }  catch (JsonSyntaxException e){
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
}

解析JSONArray

import com.google.gson.JsonParser;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;
import com.google.gson.JsonSyntaxException;
import com.google.gson.JsonIOException;

import java.io.FileNotFoundException;
import java.io.FileReader;

public class ReadJsonArray {
    public static void main(String []args) {
        JsonParser parse = new JsonParser();
        try {
            JsonObject json = (JsonObject)parse.parse(new FileReader("C:\\Users\\jihite\\IdeaProjects\\TestProject\\jsontest\\src\\main\\java\\weather.json"));
            JsonObject result = json.get("result").getAsJsonObject();
            JsonArray futureArray = result.get("future").getAsJsonArray();
            for (int i = 0; i < futureArray.size(); ++i) {
                JsonObject subObj = futureArray.get(i).getAsJsonObject();
                System.out.println("------");
                System.out.println("week:" + subObj.get("week").getAsString());
                System.out.println("weather:" + subObj.get("weather").getAsString());
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (JsonIOException e) {
            e.printStackTrace();
        } catch (JsonSyntaxException e) {
            e.printStackTrace();
        }
    }
}

注意

文件路径相对路径是从工程根目录开始