【发布时间】：2020-11-30 05:43:55
【问题描述】：
我对 Json 解析和使用 API 非常陌生，所以我不知道为什么会发生这种情况。如果您能帮助解决问题，我们将不胜感激。
现在解决问题。
在创建我的 Springboot 应用程序时，我在尝试显示来自 openweathermap 的 API 数据时遇到了一个我无法弄清楚的 JSONException。
org.json.JSONException：java.lang.String 类型的 HTTP 值无法转换为 JSONObject
好像发生在这一行
String city = getCityById(id);
这是完整的 Java 文件（我的 api 密钥已编辑）
package Homework4_API.Homework4.controllers;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import org.json.JSONObject;
import javax.net.ssl.HttpsURLConnection;
@RestController
public class MainController {
@RequestMapping(value = "/get", method = RequestMethod.GET)
public ModelAndView get(@RequestParam("id") String id) {
ModelAndView mv = new ModelAndView ("redirect:/");
String city = getCityById(id);
try{
JSONObject json = new JSONObject(city);
mv.addObject("name", json.getString("name"));
mv.addObject("temperature", json.getJSONObject("main").get("temp").toString());
mv.addObject("feels_like", json.getJSONObject("main").get("feels_like").toString());
mv.addObject("humidity", json.getJSONObject("main").get("humidity").toString());
mv.addObject("weather", json.getJSONObject("weather").get("description").toString());
}
catch (Exception e){
System.out.println(e.toString());
}
return mv;
}
private String getCityById(String id){
try {
String apiKey = "[redacted]";
URL URLForRequest = new URL("https://api.openweathermap.org/data/2.5/weather?q=" + id + "&appid=" + apiKey);
HttpsURLConnection connection = (HttpsURLConnection) URLForRequest.openConnection();
connection.setRequestMethod("GET");
if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
BufferedReader in = new BufferedReader(
new InputStreamReader(connection.getInputStream()));
StringBuilder response = new StringBuilder();
String line;
while ((line = in.readLine()) != null){
response.append(line);
}
in.close();
return response.toString();
}
else {
return "HTTP SAID NOOOOOO!!";
}
}
catch (Exception e){
return "HTTP Said No";
}
}
}
class City
{
private String City;
public City(){
City = "DEFAULT";
}
public City(String c) {
City = c;
}
public String getCity() {
return City;
}
}
HTML 文件
<!DOCTYPE html>
<html>
<head>
<title></title>
<style><%@include file ="../css/style.css"%></style>
</head>
<body>
<h1>Please Select A City</h1>
<form method="get" action="/get/">
<select name = "id">
<option value ="1">Houston</option>
<option value ="2">San Antonio</option>
<option value ="3">Dallas</option>
<option value ="4">Austin</option>
<option value ="5">Fort Worth</option>
<option value ="6">Phoenix</option>
<option value ="7">Atlanta</option>
<option value ="8">Chicago</option>
<option value ="9">Los Angles</option>
<option value ="10">New York City</option>
</select>
<input type="submit" value="Submit">
</form>
<div>
<h2>City</h2> <h3><%=request.getParameter("name")%></h3>
<h2>Temperature</h2> <h3><%=request.getParameter("temperature")%></h3>
<h2>Feels Like</h2> <h3><%=request.getParameter("feels_like")%></h3>
<h2>Humidity</h2> <h3><%=request.getParameter("humidity")%></h3>
<h2>Weather</h2> <h3><%=request.getParameter("weather")%></h3>
</div>
<hr>
<div>
<h2>Previously Requested Cities</h2>
</div>
</hr>
</body>
</html>
XML 文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.0</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>Homework4_API</groupId>
<artifactId>Homework4</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>Homework4</name>
<description>Spring boot for homework 4</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
</dependency>
<dependency>
<groupId>com.vaadin.external.google</groupId>
<artifactId>android-json</artifactId>
<version>0.0.20131108.vaadin1</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>com.vaadin.external.google</groupId>
<artifactId>android-json</artifactId>
<version>0.0.20131108.vaadin1</version>
<scope>compile</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
我确实有一个没有任何内容的 css 文件、一个应用程序文件和一个主运行文件，但我认为他们没有做任何事情来导致这个特定问题。
【问题讨论】：
标签： java json spring spring-boot jsonexception