[英]JSON Value Parsing Android Studio
I am currently learning how to create apps on Android Studio and have been trying to make a JSON connection with a server and bring back the information from the server and display it in my app. 我目前正在学习如何在Android Studio上创建应用,并且一直在尝试与服务器建立JSON连接,并从服务器获取信息并将其显示在我的应用中。 I have been able to make the connection as logical shows however I am unclear of the error that faces me and how to solve it.
我已经能够按照逻辑显示进行连接,但是我不清楚面临的错误以及如何解决它。 I will show here my two classes I have constructed to make the JSON connection and the error I am shown.
我将在这里显示我为建立JSON连接而构造的两个类以及显示的错误。 When I run the emulator it just says, Unfotunatley, JSONconnection app has stopped working.
当我运行模拟器时,它只是说,Unfotunatley,JSONconnection应用程序已停止工作。
Thanks for the help 谢谢您的帮助
Error on logcat with exception logcat发生错误,出现异常
04-08 08:10:23.860 1656-1656/com.example.adam.jsonconnection E/JSON Parser﹕ Error parsing data org.json.JSONException: Value [{"id":"170656","RatingValue":"5","DistanceKM":"0.0483604565731744","PostCode":"M1 5QS","Latitude":"53.472442","BusinessName":"Cheeky Coffee Co","Longitude":"-2.240435","RatingDate":"2014-02-06","AddressLine1":"Unit 10, The Quadrangle","AddressLine2":"Chester Street","AddressLine3":"Manchester"},{"id":"171710","RatingValue":"3","DistanceKM":"0.0483604565731744","PostCode":"M1 5QS","Latitude":"53.472442","BusinessName":"Nando's","Longitude":"-2.240435","RatingDate":"2013-01-17","AddressLine1":"Unit 3, The Quadrangle","AddressLine2":"Chester Street","AddressLine3":"Manchester"},{"id":"172780","RatingValue":"4","DistanceKM":"0.0483604565731744","PostCode":"M1 5QS","Latitude":"53.472442","BusinessName":"Zouk Tea Bar & Grill","Longitude":"-2.240435","RatingDate":"2010-06-11","AddressLine1":"Unit 5 The Quadrangle","AddressLine2":"Chester Street","AddressLine3":"Manchester"},{"id":"170593","RatingValue":"5","DistanceKM":"0.0858826413670853","PostCode":"M1 5QA","Latitude":"53.472901","BusinessName":"Caffe Nero","Longitude":"-2.23997","RatingDate":"2011-01-18","AddressLine1":"","AddressLine2":"8A Oxford Road","AddressLine3":"Manchester"},{"id":"171089","RatingValue":"5","DistanceKM":"0.0858826413670853","PostCode":"M1 5QA","Latitude":"53.472901","BusinessName":"Greggs","Longitude":"-2.23997","RatingDate":"2011-01-18","AddressLine1":"","AddressLine2":"10 Oxford Road","AddressLine3":"Manchester"},{"id":"171185","RatingValue":"5","DistanceKM":"0.0858826413670853","PostCode":"M1 5QA","Latitude":"53.472901","BusinessName":"Holiday Inn Express","Longitude":"-2.23997","RatingDate":"2011-03-17","AddressLine1":"","AddressLine2":"2-4 Oxford Road","AddressLine3":"Manchester"},{"id":"171382","RatingValue":"1","DistanceKM":"0.0858826413670853","PostCode":"M1 5QA","Latitude":"53.472901","BusinessName":"Kukoos","Longitude":"-2.23997","RatingDate":"2013-11-18","AddressLine1":"","AddressLine2":"12a Oxford Road","AddressLine3":"Manchester"},{"id":"171404","RatingValue":"-1","DistanceKM":"0.0858826413670853","PostCode":"M1 5QA","Latitude":"53.472901","BusinessName":"Ladbrokes","Longitude":"-2.23997","RatingDate":"2010-11-09","AddressLine1":"","AddressLine2":"10B Oxford Road","AddressLine3":"Manchester"},{"id":"172281","RatingValue":"5","DistanceKM":"0.0858826413670853","PostCode":"M1 5QA","Latitude":"53.472901","BusinessName":"Subway","Longitude":"-2.23997","RatingDate":"2013-10-09","AddressLine1":"","AddressLine2":"12 Oxford Road","AddressLine3":"Manchester"},{"id":"171119","RatingValue":"5","DistanceKM":"0.100210503082758","PostCode":"M1 5GE","Latitude":"53.47208","BusinessName":"H & M Convenience Store","Longitude":"-2.241442","RatingDate":"2010-09-16","AddressLine1":"Student Village","AddressLine2":"Lower Chatham Street","AddressLine3":"Manchester"}] of type org.json.JSONArray cannot be converted to JSONObject
04-08 08:10:23.860 1656-1656/com.example.adam.jsonconnection D/AndroidRuntime﹕ Shutting down VM
04-08 08:10:23.860 1656-1656/com.example.adam.jsonconnection W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb2cbdb20)
04-08 08:10:23.860 1656-1656/com.example.adam.jsonconnection E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.adam.jsonconnection, PID: 1656
JSONParser Class JSONParser类
package com.example.adam.jsonconnection;
import android.util.Log;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
MainActivity Class MainActivity类
package com.example.adam.jsonconnection;
import android.os.StrictMode;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class MainActivity extends ActionBarActivity {
//URL to get JSON Array
private static String url = "";
//JSON Node Names
private static final String TAG_NEAREST = "nearest";
private static final String TAG_BusinessName = "BusinessName";
JSONArray nearest = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Creating new JSON Parser
JSONParser jParser = new JSONParser();
// Getting JSON from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting JSON Array
nearest = json.getJSONArray(TAG_NEAREST);
JSONObject c = nearest.getJSONObject(0);
// Storing JSON item in a Variable
String businessName = c.getString(TAG_BusinessName);
//Importing TextView
final TextView BusinessNameText = (TextView)findViewById(R.id.BusinessName);
//Set JSON Data in TextView
BusinessNameText.setText(businessName);
} catch (JSONException e) {
e.printStackTrace();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
You have a JSONArray
and you're attempting to create a JSONObject
object with it. 您有一个
JSONArray
并尝试使用它创建一个JSONObject
对象。
Simple change your code to: 只需将代码更改为:
try {
jObj = new JSONArray(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
Or edit your response so that it is a json object. 或编辑您的响应,使其成为json对象。
Your JSON is an Array from root, so you must change from: 您的JSON是根目录下的Array,因此您必须更改以下内容:
JSONObject json = jParser.getJSONFromUrl(url);
to 至
JSONArray json = jParser.getJSONFromUrl(url);
and return a JSONArray
from getJSONFromUrl
并从
getJSONFromUrl
返回JSONArray
// try parse the string to a JSON object
try {
jObj = new JSONArray(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
I suggest you to use: 我建议您使用:
jsonObject.optString("your_key");
instead of: 代替:
jsonObject.getString("your_key");
this will automatically handle possible "null" values 这将自动处理可能的“空”值
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.