没有数组名称的JSONArray（地震示例）
[英]JSONArray without array name (earthquake example)
问题描述
Regarding another thread here i try too, to get a json array form a json. 
关于另一个线程，我也尝试从json获取json数组。 I have the following files : 我有以下文件：
earthquake.json earthquake.json
[{
"eqid": "merge",
"magnitude": 8.8,
"lng": 142.369,
"src": "us",
"datetime": "2011-03-11 04:46:23",
"depth": 24.4,
"lat": 38.322
}, {
"eqid": "merge2",
"magnitude": 8.6,
"lng": 93.0632,
"src": "us",
"datetime": "2012-04-11 06:38:37",
"depth": 22.9,
"lat": 2.311
}, {
"eqid": "2007hear",
"magnitude": 8.4,
"lng": 101.3815,
"src": "us",
"datetime": "2007-09-12 09:10:26",
"depth": 30,
"lat": -4.5172
}, {
"eqid": "c00090da",
"magnitude": 8.2,
"lng": 92.4522,
"src": "us",
"datetime": "2012-04-11 08:43:09",
"depth": 16.4,
"lat": 0.7731
}, {
"eqid": "2007aqbk",
"magnitude": 8,
"lng": 156.9567,
"src": "us",
"datetime": "2007-04-01 18:39:56",
"depth": 10,
"lat": -8.4528
}, {
"eqid": "2007hec6",
"magnitude": 7.8,
"lng": 100.9638,
"src": "us",
"datetime": "2007-09-12 21:49:01",
"depth": 10,
"lat": -2.5265
}, {
"eqid": "b000g7x7",
"magnitude": 7.8,
"lng": 62.0532,
"src": "us",
"datetime": "2013-04-16 08:44:20",
"depth": 82,
"lat": 28.1069
}, {
"eqid": "a00043nx",
"magnitude": 7.7,
"lng": 100.1139,
"src": "us",
"datetime": "2010-10-25 12:42:22",
"depth": 20.6,
"lat": -3.4841
}, {
"eqid": "2010utc5",
"magnitude": 7.7,
"lng": 97.1315,
"src": "us",
"datetime": "2010-04-06 20:15:02",
"depth": 31,
"lat": 2.3602
}, {
"eqid": "2009mebz",
"magnitude": 7.6,
"lng": 99.9606,
"src": "us",
"datetime": "2009-09-30 08:16:09",
"depth": 80,
"lat": -0.7889
}]
MainActivity.java MainActivity.java
package ayub.khosa.json_parsing;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import org.apache.http.client.ClientProtocolException;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
public class MainActivity extends ListActivity
{
String tag = "AYUB";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{ super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.listplaceholder);
Log.d(tag, "setContentView ");
ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
JSONArray json = null;
try {
json = JSONfunctions.getJSONfromURL("http://192.168.0.104/earthquakes.json");
} catch (ClientProtocolException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Log.d(tag, "json object ");
try{
Collection<?> result = null;
JSONArray json1 = new JSONArray(result);
// // ...
for(int i=0;i<json.length();i++){
HashMap<String, String> map = new HashMap<String, String>();
JSONObject e = json1.getJSONObject(i);
map.put("id", String.valueOf(i));
map.put("name", "Earthquake name:" + e.getString("eqid"));
map.put("magnitude", "Magnitude: " + e.getString("magnitude"));
mylist.add(map);
}
}catch(JSONException e) {
Log.e("log_tag", "Error parsing data "+e.toString());
}
ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.activity_main,
new String[] { "name", "magnitude" },
new int[] { R.id.item_title, R.id.item_subtitle });
setListAdapter(adapter);
final ListView lv = getListView();
lv.setTextFilterEnabled(true);
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
@SuppressWarnings("unchecked")
HashMap<String, String> o = (HashMap<String, String>) lv.getItemAtPosition(position);
Log.d(tag, "json object " + lv.getItemAtPosition(position));
Toast.makeText(MainActivity.this, "ID " + o.get("id")+" " + o.get("name") + o.get("magnitude")+".", Toast.LENGTH_SHORT).show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
JSONFunctions.java JSONFunctions.java
package ayub.khosa.json_parsing;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
public class JSONfunctions {
public static JSONArray getJSONfromURL(String url) throws ClientProtocolException, IOException, JSONException{
InputStream is = null;
String result = "";
JSONArray jArray = null;
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(url);
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
is = entity.getContent();
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();
result=sb.toString();
jArray = new JSONArray(result);
return jArray;
}
}
Problem is that appears no data on screen and i get only a warning: 问题是屏幕上没有显示任何数据，我仅收到警告：
09-21 12:09:26.225: W/ActivityManager(59): Launch timeout has expired, giving up wake lock!
09-21 12:09:26.500: W/ActivityManager(59): Activity idle timeout for HistoryRecord{43ee8ee8 ayub.khosa.json_parsing/.MainActivity}
UPDATE : 更新：
Indeed the webserver was down without i noticed. 确实，网络服务器在没有我注意的情况下就关闭了。 Now is up, i see in browser the json, but now i get the following errors: 现在到了，我在浏览器中看到json，但是现在出现以下错误：
09-21 12:30:52.301: W/ActivityManager(59): Activity destroy timeout for HistoryRecord{43f44da0 ayub.khosa.json_parsing/.MainActivity}
09-21 12:30:57.449: I/ActivityManager(59): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=ayub.khosa.json_parsing/.MainActivity }
09-21 12:30:57.609: I/ActivityManager(59): Start proc ayub.khosa.json_parsing for activity ayub.khosa.json_parsing/.MainActivity: pid=287 uid=10036 gids={3003}
09-21 12:30:58.179: D/AYUB(287): setContentView
09-21 12:30:58.339: D/AYUB(287): json object
09-21 12:30:58.339: D/AndroidRuntime(287): Shutting down VM
09-21 12:30:58.339: W/dalvikvm(287): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
09-21 12:30:58.349: E/AndroidRuntime(287): FATAL EXCEPTION: main
09-21 12:30:58.349: E/AndroidRuntime(287): java.lang.RuntimeException: Unable to start activity ComponentInfo{ayub.khosa.json_parsing/ayub.khosa.json_parsing.MainActivity}: java.lang.NullPointerException
09-21 12:30:58.349: E/AndroidRuntime(287): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
09-21 12:30:58.349: E/AndroidRuntime(287): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
09-21 12:30:58.349: E/AndroidRuntime(287): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
09-21 12:30:58.349: E/AndroidRuntime(287): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
09-21 12:30:58.349: E/AndroidRuntime(287): at android.os.Handler.dispatchMessage(Handler.java:99)
09-21 12:30:58.349: E/AndroidRuntime(287): at android.os.Looper.loop(Looper.java:123)
09-21 12:30:58.349: E/AndroidRuntime(287): at android.app.ActivityThread.main(ActivityThread.java:4627)
09-21 12:30:58.349: E/AndroidRuntime(287): at java.lang.reflect.Method.invokeNative(Native Method)
09-21 12:30:58.349: E/AndroidRuntime(287): at java.lang.reflect.Method.invoke(Method.java:521)
09-21 12:30:58.349: E/AndroidRuntime(287): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
09-21 12:30:58.349: E/AndroidRuntime(287): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
09-21 12:30:58.349: E/AndroidRuntime(287): at dalvik.system.NativeStart.main(Native Method)
09-21 12:30:58.349: E/AndroidRuntime(287): Caused by: java.lang.NullPointerException
09-21 12:30:58.349: E/AndroidRuntime(287): at java.util.ArrayList.addAll(ArrayList.java:193)
09-21 12:30:58.349: E/AndroidRuntime(287): at org.json.JSONArray.<init(JSONArray.java:70)
09-21 12:30:58.349: E/AndroidRuntime(287): at ayub.khosa.json_parsing.MainActivity.onCreate(MainActivity.java:58)
09-21 12:30:58.349: E/AndroidRuntime(287): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
09-21 12:30:58.349: E/AndroidRuntime(287): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
09-21 12:30:58.349: E/AndroidRuntime(287): ... 11 more
09-21 12:30:58.419: D/dalvikvm(287): GC_FOR_MALLOC freed 3711 objects / 261576 bytes in 67ms
09-21 12:30:58.429: W/ActivityManager(59): Force finishing activity ayub.khosa.json_parsing/.MainActivity
09-21 12:30:58.958: W/ActivityManager(59): Activity pause timeout for HistoryRecord{440757b8 ayub.khosa.json_parsing/.MainActivity}
09-21 12:31:02.689: I/Process(287): Sending signal. PID: 287 SIG: 9
09-21 12:31:02.709: I/ActivityManager(59): Process ayub.khosa.json_parsing (pid 287) has died.
09-21 12:31:02.729: W/InputManagerService(59): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@43e4ec30
09-21 12:31:09.089: W/ActivityManager(59): Activity destroy timeout for HistoryRecord{440757b8 ayub.khosa.json_parsing/.MainActivity}
UPDATE 2 - after Max edit suggestion
> 09-21 13:08:24.395: D/AYUB(272): setContentView
> 09-21 13:08:24.475: I/global(272): Default buffer size used in BufferedReader constructor. It would be better to be explicit if an 8k-char buffer is required.
> 09-21 13:08:24.475: W/System.err(272): org.json.JSONException: End of input at character 0 of
> 09-21 13:08:24.485: W/System.err(272): at org.json.JSONTokener.syntaxError(JSONTokener.java:446)
> 09-21 13:08:24.485: W/System.err(272): at org.json.JSONTokener.nextValue(JSONTokener.java:93)
> 09-21 13:08:24.495: W/System.err(272): at org.json.JSONArray.<init>(JSONArray.java:87)
> 09-21 13:08:24.495: W/System.err(272): at org.json.JSONArray.<init>(JSONArray.java:103)
> 09-21 13:08:24.495: W/System.err(272): at ayub.khosa.json_parsing.JSONfunctions.getJSONfromURL(JSONfunctions.java:41)
> 09-21 13:08:24.495: W/System.err(272): at ayub.khosa.json_parsing.MainActivity.onCreate(MainActivity.java:44)
> 09-21 13:08:24.495: W/System.err(272): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
> 09-21 13:08:24.495: W/System.err(272): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
> 09-21 13:08:24.495: W/System.err(272): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
> 09-21 13:08:24.495: W/System.err(272): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
> 09-21 13:08:24.495: W/System.err(272): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
> 09-21 13:08:24.495: W/System.err(272): at android.os.Handler.dispatchMessage(Handler.java:99)
> 09-21 13:08:24.495: W/System.err(272): at android.os.Looper.loop(Looper.java:123)
> 09-21 13:08:24.495: W/System.err(272): at android.app.ActivityThread.main(ActivityThread.java:4627)
> 09-21 13:08:24.495: W/System.err(272): at java.lang.reflect.Method.invokeNative(Native Method)
> 09-21 13:08:24.505: W/System.err(272): at java.lang.reflect.Method.invoke(Method.java:521)
> 09-21 13:08:24.505: W/System.err(272): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
> 09-21 13:08:24.505: W/System.err(272): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
> 09-21 13:08:24.505: W/System.err(272): at dalvik.system.NativeStart.main(Native Method)
> 09-21 13:08:24.505: D/AYUB(272): json object
> 09-21 13:08:24.505: D/AndroidRuntime(272): Shutting down VM
> 09-21 13:08:24.505: W/dalvikvm(272): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
> 09-21 13:08:24.515: E/AndroidRuntime(272): FATAL EXCEPTION: main
> 09-21 13:08:24.515: E/AndroidRuntime(272): java.lang.RuntimeException: Unable to start activity ComponentInfo{ayub.khosa.json_parsing/ayub.khosa.json_parsing.MainActivity}: java.lang.NullPointerException
> 09-21 13:08:24.515: E/AndroidRuntime(272): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at android.os.Handler.dispatchMessage(Handler.java:99)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at android.os.Looper.loop(Looper.java:123)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at android.app.ActivityThread.main(ActivityThread.java:4627)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at java.lang.reflect.Method.invokeNative(Native Method)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at java.lang.reflect.Method.invoke(Method.java:521)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at dalvik.system.NativeStart.main(Native Method)
> 09-21 13:08:24.515: E/AndroidRuntime(272): Caused by: java.lang.NullPointerException
> 09-21 13:08:24.515: E/AndroidRuntime(272): at java.util.ArrayList.addAll(ArrayList.java:193)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at org.json.JSONArray.<init>(JSONArray.java:70)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at ayub.khosa.json_parsing.MainActivity.onCreate(MainActivity.java:58)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
> 09-21 13:08:24.515: E/AndroidRuntime(272): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
> 09-21 13:08:24.515: E/AndroidRuntime(272): ... 11 more
> 09-21 13:08:27.035: I/Process(272): Sending signal. PID: 272 SIG: 9
3 个解决方案
解决方案1
1 已采纳 2013-09-21 12:39:09
Try to change your GET a bit: 尝试稍微更改一下GET：
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(url);
StringBuilder sb = new StringBuilder();
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
if (entity != null) {
entity.consumeContent();
}
...
InputStream is = entity.getContent();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader sb = new BufferedReader(isr);
String line = null;
while ( (line = br.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
// before conversion to JSONArray print it:
Log.d("Fess", result);
jArray = new JSONArray(result);
[EDIT] [编辑]
from your logs I see: 从您的日志中，我看到：
Caused by: java.lang.NullPointerException
at java.util.ArrayList.addAll(ArrayList.java:193)
解决方案2
0 2013-09-21 12:36:12
I would like to suggest changing the JSON format into : 我想建议将JSON格式更改为：
{"earthquake" : [Your Original JSON Here]}
To parse the JSON, you will need to create a new JSONObject , for example, we save the json string into a string called jsontext , create a new JSONObject like : 要解析JSON，您将需要创建一个新的JSONObject ，例如，我们将json字符串保存到一个名为jsontext的字符串中，创建一个新的JSONObject例如：
JSONObject mainObject = new JSONObject(jsontext);
take the array "earthquake" : 取数组“地震”：
JSONArray Earthquake = mainObject.getJSONArray("earthquake");
then just parse it like usual. 然后像往常一样解析它。
For some reason, the JSONArray will be null if you create it without encapsulating it inside an object. 出于某种原因，如果您创建JSONArray而不将其封装在对象中，则JSONArray将为null。
Hope this helps, Good luck ^^ 希望这会有所帮助，祝你好运^^
Regards, 问候，
Reid 里德
EDIT : Check whether this code has the JSON String -> result=sb.toString(); 编辑：检查此代码是否具有JSON字符串-> result=sb.toString();
Append the string like this : String jsondata = "{\\"data\\":" + result + "}"; 像这样添加字符串： String jsondata = "{\\"data\\":" + result + "}";
Parse the json as I explained above 正如我上面解释的那样解析json
解决方案3
0 2015-03-31 11:59:46
I saw an opensource project in http://remotegun.com on Android and Xcode. 我在http://remotegun.com上的Android和Xcode上看到了一个开源项目。 contact with this address earthquake app 与此地址联系地震应用程序
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.
相关问题
Java-解决简单数组地震程序 - Java - solve simple array earthquake program
HighCharts JSONArray不带引号 - HighCharts JSONArray without quotes
Java语法：JSONArray array =（JSONArray）obj - Java Syntax: JSONArray array = (JSONArray)obj
将JSONArray字符串转换为数组 - Converting JSONArray String to array
Gson数组字符串到JsonArray - Gson Array of Strings to JsonArray
java原始数组到JSONArray - java primitive array to JSONArray
JSONArray的阵列适配器出现问题 - Trouble with Array Adapter for JSONArray
将 JSONArray 转换为字符串数组 - Convert JSONArray to String Array
将JSONArray转换为String []数组 - Convert JSONArray to String[] Array
JSONArray到字符串数组 - JSONArray to string array
相关标签