打印JSON值 [英] Printing JSON values

问题描述

 forecast：{
txt_forecast：{
date：8:00 AM MST，
forecastday：[
 {
period：0，
 icon：partiallycloudy，
icon_url：http://icons-ak.wxug.com/i/c/k/partlycloudy.gif，
title：星期四，
fcttext：部分多云，最高63°，风速低于5英里/小时，
fcttext_metric：部分多云，高达17C，风速低于5公里/小时。 ，
pop：0
} 
  

打印嵌套的JSON值。如果我想打印fcttext，我该如何去做呢？ JSONParser parser = new JSONParser（）（）;} $ J $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $' ;
尝试{
Object obj = parser.parse（new FileReader（C：\\ABC.json））;

JSONObject jsonObject =（JSONObject）obj;
String a =（String）jsonObject.get（forecast）。toString（）;
System.out.println（a）;
}
catch（FileNotFoundException e）{
e.printStackTrace（）;

catch（IOException e）{
e.printStackTrace（）;

catch（ParseException e）{
e.printStackTrace（）;




$ b

我在做什么错误？ 完整的JSON代码。

首先，你的json是不正确的，使用jsonlint [1]来检查你的json是否格式正确。

>

将您的JSON格式化为以下内容：

  {
forecast ：{
txt_forecast：{
date：8：00AMMST，
forecastday：[
 {
period：0，
icon：partiallycloudy，
icon_url：http：//icons-ak.wxug.com/i/c/k/partlycloudy.gif，
title ：
fcttext：Partlycloudy.Highof63F.Windslessthan5mph。，
fcttext_metric：Partlycloudy.Highof17C.Windslessthan5km / h。，
pop： 0
} 
] 
 
 
 
 
 
 $ p $使用下面的代码解析
  package com.aamir.stackoverflow; 
 
 import com.google.gson.JsonArray; 
 import com.google.gson.JsonElement; 
 import com.google.gson.JsonObject; 
 import com.google.gson.JsonParser; 
 $ b $ public class JSONParserStackOverflow {
 public static void main（String [] args）{
 
 String request ={\+ 
 \forecast\：{\ n+ 
\txt_forecast \：{\ n+ 
\date \：\8 ：AMMST \，\\\
+ 
\forecastday \：[\\\
+ 
{\ n+ 
\ \：0，\\\
+ 
\icon \：\partiallycloudy \，\\\
+ 
\icon_url\： \http：//icons-ak.wxug.com/i/c/k/partlycloudy.gif\\",\\\
+ 
\title \：\星期四\，\\\
+ 
\fcttext \：\Partlycloudy.Highof6 3F.Windslessthan5mph.\，\\\
+ 
\fcttext_metric \：\Partlycloudy.Highof17C.Windslessthan5km / h.\，\\\
+ 
 \pop \：\0 \\\\
+ 
} \\\
+ 
] \ n+ 
} \\ \\ n+ 
} \\\
+ 
}; 
 
 JsonElement weatherJSON = new JsonParser（）。parse（request）; 
 JsonObject weatherObj = weatherJSON.getAsJsonObject（）; 
 JsonObject forecastObj = weatherObj.get（forecast）。getAsJsonObject（）; 
 JsonObject txt_forecast = forecastObj.get（txt_forecast）。getAsJsonObject（）; 
 
 JsonArray forecastDays = txt_forecast.getAsJsonArray（forecastday）; （JsonElement forecastDay：forecastDays）{
 System.out.println（forecastDay.getAsJsonObject（）。get（fcttext）。toString（））; 
 
 
 
 
 
 $ b $ / code $ / pre 
 $ b我已经使用Google的GSON [ 2]库来解析JSON。
 
 
 
 [1]  http：// jsonlint .com /  
 
 
 
 [2]  https://code.google.com/p/google-gson/  
 
Here's just a chunk of JSON code that I need to access...
"forecast":{
        "txt_forecast": {
        "date":"8:00 AM MST",
        "forecastday": [
        {
        "period":0,
        "icon":"partlycloudy",
        "icon_url":"http://icons-ak.wxug.com/i/c/k/partlycloudy.gif",
        "title":"Thursday",
        "fcttext":"Partly cloudy. High of 63F. Winds less than 5 mph.",
        "fcttext_metric":"Partly cloudy. High of 17C. Winds less than 5 km/h.",
        "pop":"0"
        }
Im having trouble printing nested JSON values. If I wanted to print the "fcttext", how would I go upon doing that? I've tried this...
public static void display() {
         JSONParser parser = new JSONParser();
         try {
             Object obj = parser.parse(new FileReader("C:\\ABC.json"));

         JSONObject jsonObject = (JSONObject) obj;
             String a = (String) jsonObject.get("forecast").toString();
             System.out.println(a);
     } 
         catch (FileNotFoundException e) {
         e.printStackTrace();
     } 
         catch (IOException e) {
         e.printStackTrace();
     } 
         catch (ParseException e) {
             e.printStackTrace();
     }
     }
What am I doing wrong? Full JSON code.
解决方案
First of all your json is not proper, use jsonlint[1] to check if your json is properly formatted.

Reformatting your JSON to following,
{
    "forecast": {
        "txt_forecast": {
            "date": "8: 00AMMST",
            "forecastday": [
                {
                    "period": 0,
                    "icon": "partlycloudy",
                    "icon_url": "http: //icons-ak.wxug.com/i/c/k/partlycloudy.gif",
                    "title": "Thursday",
                    "fcttext": "Partlycloudy.Highof63F.Windslessthan5mph.",
                    "fcttext_metric": "Partlycloudy.Highof17C.Windslessthan5km/h.",
                    "pop": "0"
                }
            ]
        }
    }
}
Use following code to parse,
package com.aamir.stackoverflow;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

public class JSONParserStackOverflow {
    public static void main(String[] args) {

        String request = "{\n" +
                "    \"forecast\": {\n" +
                "        \"txt_forecast\": {\n" +
                "            \"date\": \"8: 00AMMST\",\n" +
                "            \"forecastday\": [\n" +
                "                {\n" +
                "                    \"period\": 0,\n" +
                "                    \"icon\": \"partlycloudy\",\n" +
                "                    \"icon_url\": \"http: //icons-ak.wxug.com/i/c/k/partlycloudy.gif\",\n" +
                "                    \"title\": \"Thursday\",\n" +
                "                    \"fcttext\": \"Partlycloudy.Highof63F.Windslessthan5mph.\",\n" +
                "                    \"fcttext_metric\": \"Partlycloudy.Highof17C.Windslessthan5km/h.\",\n" +
                "                    \"pop\": \"0\"\n" +
                "                }\n" +
                "            ]\n" +
                "        }\n" +
                "    }\n" +
                "}";

        JsonElement weatherJSON = new JsonParser().parse(request);
        JsonObject weatherObj = weatherJSON.getAsJsonObject();
        JsonObject forecastObj = weatherObj.get("forecast").getAsJsonObject();
        JsonObject txt_forecast = forecastObj.get("txt_forecast").getAsJsonObject();

        JsonArray forecastDays = txt_forecast.getAsJsonArray("forecastday");


        for(JsonElement forecastDay : forecastDays) {
            System.out.println(forecastDay.getAsJsonObject().get("fcttext").toString());
        }
    }
}
I have used Google's GSON[2] library to parse JSON.

[1] http://jsonlint.com/

[2] https://code.google.com/p/google-gson/

                        
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