我正在创建壁纸应用。我正在使用在线存储在服务器中的JSON数据库。 当我启动应用程序时,出现此错误:
org.json.JSONException: No value for index
这是我的JSON:
[
{
"wallpaper_index":"0",
"wallpaper_name":"Sky",
"wallpaper_site_name":"Pinimg",
"wallpaper_site_url":"https://pinimg.com",
"wallpaper_url":"https://i.pinimg.com/564x/fb/1d/55/fb1d55a3523710250eb84e2b32cc8dec.jpg"
},
{
"wallpaper_index":"1",
"wallpaper_name":"Bear",
"wallpaper_site_name":"Imgur",
"wallpaper_site_url":"https://imgur.com",
"wallpaper_url":"https://i.imgur.com/OQ4BYiK.jpg"
},
{
"wallpaper_index":"2",
"wallpaper_name":"Lion",
"wallpaper_site_name":"Alphacoders",
"wallpaper_site_url":"https://alphacoders.com",
"wallpaper_url":"https://mfiles.alphacoders.com/710/710991.jpg"
},
{
"wallpaper_index":"3",
"wallpaper_name":"Oleander Art",
"wallpaper_site_name":"Pinimg",
"wallpaper_site_url":"https://pinimg.com",
"wallpaper_url":"https://i.pinimg.com/564x/35/08/44/3508441000ac03dc1c394580b223136f.jpg"
},
{
"wallpaper_index":"4",
"wallpaper_name":"Water",
"wallpaper_site_name":"Pinimg",
"wallpaper_site_url":"https://pinimg.com",
"wallpaper_url":"https://i.pinimg.com/originals/97/9e/e4/979ee4273e27ffd90d15327472eb26e8.jpg"
},
{
"wallpaper_index":"5",
"wallpaper_name":"Amazing Art",
"wallpaper_site_name":"Vactualpapers",
"wallpaper_site_url":"https://vactualpapers.com",
"wallpaper_url":"http://www.vactualpapers.com/web/images/Abstract/Abstract%20Design%20Pattern%20Shape%20HD%20Mobile%20Wallpaper%20117.jpg"
},
{
"wallpaper_index":"6",
"wallpaper_name":"Mountain",
"wallpaper_site_name":"Pinimg",
"wallpaper_site_url":"https://pinimg.com",
"wallpaper_url":"https://i.pinimg.com/564x/7d/00/e4/7d00e444b1fd4978686f00f7299c2465.jpg"
},
{
"wallpaper_index":"7",
"wallpaper_name":"Morning",
"wallpaper_site_name":"Pinimg",
"wallpaper_site_url":"https://pinimg.com",
"wallpaper_url":"https://i.pinimg.com/564x/3a/69/89/3a69891eb17c1dbdf74a2e78d9a7a4a5.jpg"
},
{
"wallpaper_index":"8",
"wallpaper_name":"Space man",
"wallpaper_site_name":"Imgur",
"wallpaper_site_url":"https://imgur.com",
"wallpaper_url":"https://i.imgur.com/hrNAPRJ.jpg"
},
{
"wallpaper_index":"9",
"wallpaper_name":"Pattern Shape",
"wallpaper_site_name":"Vactualpapers",
"wallpaper_site_url":"https://vactualpapers.com",
"wallpaper_url":"http://www.vactualpapers.com/web/images/Abstract/Abstract%20Design%20Pattern%20Shape%20HD%20Mobile%20Wallpaper%20113.jpg"
},
{
"wallpaper_index":"10",
"wallpaper_name":"Red Car",
"wallpaper_site_name":"Alphacoders",
"wallpaper_site_url":"https://alphacoders.com",
"wallpaper_url":"https://mfiles.alphacoders.com/710/710763.jpg"
},
{
"wallpaper_index":"11",
"wallpaper_name":"Paris",
"wallpaper_site_name":"Vactualpapers",
"wallpaper_site_url":"https://vactualpapers.com",
"wallpaper_url":"http://www.vactualpapers.com/web/images/Abstract/Abstract%20Design%20Pattern%20Shape%20HD%20Mobile%20Wallpaper%20118.jpg"
},
{
"wallpaper_index":"12",
"wallpaper_name":"Abstract Design",
"wallpaper_site_name":"Vactualpapers",
"wallpaper_site_url":"https://vactualpapers.com",
"wallpaper_url":"http://www.vactualpapers.com/web/images/Abstract/Abstract%20Design%20Pattern%20Shape%20HD%20Mobile%20Wallpaper%20145.jpg"
},
{
"wallpaper_index":"13",
"wallpaper_name":"Nature",
"wallpaper_site_name":"Pinimg",
"wallpaper_site_url":"https://pinimg.com",
"wallpaper_url":"https://i.pinimg.com/564x/c9/3d/3d/c93d3d8e3667c2f2453611395171f6a0.jpg"
}
]
这是我的飞溅活动代码,其中已加载JSON数据库:
package com.king.goldwallpapers;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.Toast;
import com.king.goldwallpapers.func.DataUrl;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import comm.king.goldwallpapers.R;
public class SplashActivity extends AppCompatActivity {
public static final int CONNECTION_TIMEOUT = 10000;
public static final int READ_TIMEOUT = 15000;
protected static List<DataUrl> data = new ArrayList<>();
private final String ourDataFilenameNoSlash = "goldwallpapers.json";
private final String ourDataFilename = "/" + ourDataFilenameNoSlash;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
new AsyncFetch().execute();
}
private boolean isNetworkAvailable(Context context) {
int[] networkTypes = {ConnectivityManager.TYPE_MOBILE,
ConnectivityManager.TYPE_WIFI};
try {
ConnectivityManager connectivityManager =
(ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
for (int networkType : networkTypes) {
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
if (activeNetworkInfo != null &&
activeNetworkInfo.getType() == networkType)
return true;
}
} catch (Exception e) {
return false;
}
return false;
}
private void writeJsonToFile(String data, Context context) {
try {
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(context.openFileOutput(ourDataFilenameNoSlash, Context.MODE_PRIVATE));
outputStreamWriter.write(data);
outputStreamWriter.close();
Log.i("io", "Wrote file");
} catch (IOException e) {
e.printStackTrace();
}
}
protected String buffToString(Reader ourReader, boolean save) {
try {
BufferedReader reader = new BufferedReader(ourReader);
StringBuilder result = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
result.append(line);
}
// write it to ourdata.json
if (save) {
if (!result.toString().equals(null)) {
writeJsonToFile(result.toString(), SplashActivity.this);
}
}
return (result.toString());
} catch (IOException e) {
e.printStackTrace();
return e.toString();
}
}
private class AsyncFetch extends AsyncTask<String, String, String> {
HttpURLConnection connection;
URL url = null;
@Override
protected String doInBackground(String... strings) {
if (isNetworkAvailable(SplashActivity.this)) {
try {
url = new URL(SettingsClasse.wallpaperDataBase);
} catch (MalformedURLException e) {
e.printStackTrace();
return e.toString();
}
try {
connection = (HttpURLConnection) url.openConnection();
connection.setReadTimeout(READ_TIMEOUT);
connection.setConnectTimeout(CONNECTION_TIMEOUT);
connection.setRequestMethod("GET");
} catch (IOException e1) {
e1.printStackTrace();
return e1.toString();
}
try {
int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
InputStream inputStream = connection.getInputStream();
return buffToString(new InputStreamReader(inputStream), true);
} else {
File ourData = new File(SplashActivity.this.getFilesDir().getPath() + ourDataFilename);
if (ourData.exists()) {
return buffToString(new FileReader(ourData), false);
} else {
Toast.makeText(SplashActivity.this, "Cannot connect to server, please reopen app and try again.", Toast.LENGTH_SHORT).show();
return ("unsuccessful");
}
}
} catch (IOException e2) {
e2.printStackTrace();
return e2.toString();
} finally {
connection.disconnect();
}
} else {
File ourData = new File(SplashActivity.this.getFilesDir().getPath() + ourDataFilename);
try {
return buffToString(new FileReader(ourData), false);
} catch (IOException e) {
e.printStackTrace();
return e.toString();
}
}
}
@Override
protected void onPostExecute(String result) {
try {
JSONArray jsonArray = new JSONArray(result);
// Extract data from json and store into ArrayList as class objects
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonData = jsonArray.getJSONObject(i);
DataUrl dataUrl = new DataUrl();
dataUrl.wallIndex = jsonData.getInt("index");
dataUrl.wallName = jsonData.getString("wallpaper_name");
dataUrl.wallSite = jsonData.getString("wallpaper_site_name");
dataUrl.wallSiteUrl = jsonData.getString("wallpaper_site_url");
dataUrl.wallURL = jsonData.getString("wallpaper_url");
data.add(dataUrl);
}
} catch (JSONException e) {
Toast.makeText(SplashActivity.this, e.toString(), Toast.LENGTH_LONG).show();
}
}
}
}
我到处搜索,但找不到解决方案,我尝试了一些有关同一错误的已有答案,但对我没有任何帮助。
我认为这是一个与jsonObject相关的错误,但我无法弄清楚。
答案 0 :(得分:1)
您不是要寻找wallpaper_index
而不是index
吗?但是,如果是这样,则为string
,而不是int
,因为您当前的代码假定:
dataUrl.wallIndex = jsonData.getInt("index");
您应该这样做
dataUrl.wallIndex = Integer.valueOf(jsonData.getString("wallpaper_index"));
编辑
可以删除显式转换:
dataUrl.wallIndex = jsonData.getInt("wallpaper_index");
getInt()
中的documentation说它应该自动发生:
返回按名称映射的值(如果存在)并且是int或可以强制转换为int ,否则抛出该值。