这是我的JSON结构
网址 ::
http://54.218.73.244:7004/DescriptionSortedPrice/
JSON ::
{
"restaurants": [
{
"Sl_no": 1,
"Person_Name": "salmanKhan",
"Image_Name": "image.jpg"
},
Adapter.java
public class Adapter extends BaseAdapter {
// Declare Variables
Context context;
LayoutInflater inflater;
ArrayList<HashMap<String, String>> data;
HashMap<String, String> resultp = new HashMap<String, String>();
public Adapter(Context context,
ArrayList<HashMap<String, String>> arraylist) {
this.context = context;
data = arraylist;
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
public View getView(final int position, View convertView, ViewGroup parent) {
// Declare Variables
TextView name;
inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View itemView = inflater.inflate(R.layout.single_item, parent, false);
// Get the position
resultp = data.get(position);
// Locate the TextViews in listview_item.xml
name = (TextView) itemView.findViewById(R.id.title_textView_id);
// Capture position and set results to the TextViews
name.setText(resultp.get(MainActivity.NAME));
return itemView;
}
}
MainActivity.java
public class MainActivity extends Activity{
// Declare Variables
JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
Adapter adapter;
ProgressDialog mProgressDialog;
ArrayList<HashMap<String, String>> arraylist;
static String NAME = "rank";
String TYPE_FILTER;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the view from listview_main.xml
setContentView(R.layout.activity_main);
listview = (ListView) findViewById(R.id.listView_id);
// Execute DownloadJSON AsyncTask
new DownloadJSON().execute();
}
// DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(MainActivity.this);
// Set progressdialog title
//mProgressDialog.setTitle("Fetching the information");
// Set progressdialog message
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
// Retrieve JSON Objects from the given URL address
jsonobject = Parser.getJSONfromURL("http://54.218.73.244:7004/DescriptionSortedPrice/");
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("restaurants");
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
map.put(MainActivity.NAME, jsonobject.getString("Person_Name"));
// Set the JSON Objects into the array
arraylist.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Pass the results into ListViewAdapter.java
adapter = new Adapter(MainActivity.this, arraylist);
// Set the adapter to the ListView
listview.setAdapter(adapter);
// Close the progressdialog
mProgressDialog.dismiss();
}
}
}
Parser.java
public class Parser {
public static JSONObject getJSONfromURL(String url) {
InputStream is = null;
String result = "";
JSONObject jArray = null;
// Download JSON data from URL
try {
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(url);
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
// Convert response to string
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();
result = sb.toString();
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}
try {
jArray = new JSONObject(result);
} catch (JSONException e) {
Log.e("log_tag", "Error parsing data " + e.toString());
}
return jArray;
}
}
日志::
01-01 12:13:14.600: E/log_tag(715): Error in http connection java.net.SocketException: Permission denied
01-01 12:13:14.610: E/log_tag(715): Error converting result java.lang.NullPointerException
01-01 12:13:14.620: E/log_tag(715): Error parsing data org.json.JSONException: End of input at character 0 of
01-01 12:13:14.660: W/dalvikvm(715): threadid=7: thread exiting with uncaught exception (group=0x4001d800)
01-01 12:13:14.690: E/AndroidRuntime(715): FATAL EXCEPTION: AsyncTask #1
01-01 12:13:14.690: E/AndroidRuntime(715): java.lang.RuntimeException: An error occured while executing doInBackground()
01-01 12:13:14.690: E/AndroidRuntime(715): at android.os.AsyncTask$3.done(AsyncTask.java:200)
01-01 12:13:14.690: E/AndroidRuntime(715): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
01-01 12:13:14.690: E/AndroidRuntime(715): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
01-01 12:13:14.690: E/AndroidRuntime(715): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
01-01 12:13:14.690: E/AndroidRuntime(715): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
01-01 12:13:14.690: E/AndroidRuntime(715): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
01-01 12:13:14.690: E/AndroidRuntime(715): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
01-01 12:13:14.690: E/AndroidRuntime(715): at java.lang.Thread.run(Thread.java:1096)
01-01 12:13:14.690: E/AndroidRuntime(715): Caused by: java.lang.NullPointerException
01-01 12:13:14.690: E/AndroidRuntime(715): at com.example.singleitemlistview.MainActivity$DownloadJSON.doInBackground(MainActivity.java:71)
01-01 12:13:14.690: E/AndroidRuntime(715): at com.example.singleitemlistview.MainActivity$DownloadJSON.doInBackground(MainActivity.java:1)
01-01 12:13:14.690: E/AndroidRuntime(715): at android.os.AsyncTask$2.call(AsyncTask.java:185)
01-01 12:13:14.690: E/AndroidRuntime(715): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
01-01 12:13:14.690: E/AndroidRuntime(715): ... 4 more
01-01 12:13:17.215: E/WindowManager(715): Activity com.example.singleitemlistview.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@45fbe1e8 that was originally added here
01-01 12:13:17.215: E/WindowManager(715): android.view.WindowLeaked: Activity com.example.singleitemlistview.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@45fbe1e8 that was originally added here
01-01 12:13:17.215: E/WindowManager(715): at android.view.ViewRoot.<init>(ViewRoot.java:247)
01-01 12:13:17.215: E/WindowManager(715): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
01-01 12:13:17.215: E/WindowManager(715): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
01-01 12:13:17.215: E/WindowManager(715): at android.view.Window$LocalWindowManager.addView(Window.java:424)
01-01 12:13:17.215: E/WindowManager(715): at android.app.Dialog.show(Dialog.java:241)
01-01 12:13:17.215: E/WindowManager(715): at com.example.singleitemlistview.MainActivity$DownloadJSON.onPreExecute(MainActivity.java:58)
01-01 12:13:17.215: E/WindowManager(715): at android.os.AsyncTask.execute(AsyncTask.java:391)
01-01 12:13:17.215: E/WindowManager(715): at com.example.singleitemlistview.MainActivity.onCreate(MainActivity.java:41)
01-01 12:13:17.215: E/WindowManager(715): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-01 12:13:17.215: E/WindowManager(715): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
01-01 12:13:17.215: E/WindowManager(715): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
01-01 12:13:17.215: E/WindowManager(715): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
01-01 12:13:17.215: E/WindowManager(715): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
01-01 12:13:17.215: E/WindowManager(715): at android.os.Handler.dispatchMessage(Handler.java:99)
01-01 12:13:17.215: E/WindowManager(715): at android.os.Looper.loop(Looper.java:123)
01-01 12:13:17.215: E/WindowManager(715): at android.app.ActivityThread.main(ActivityThread.java:4627)
01-01 12:13:17.215: E/WindowManager(715): at java.lang.reflect.Method.invokeNative(Native Method)
01-01 12:13:17.215: E/WindowManager(715): at java.lang.reflect.Method.invoke(Method.java:521)
01-01 12:13:17.215: E/WindowManager(715): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
01-01 12:13:17.215: E/WindowManager(715): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
01-01 12:13:17.215: E/WindowManager(715): at dalvik.system.NativeStart.main(Native Method)
从日志引用 ::
问题 ::我无法在列表视图中显示已解析的项目
答案 0 :(得分：6)
您是否已获得清单中的许可
<uses-permission android:name="android.permission.INTERNET" />
因为从你的日志中得到了
http connection java.net.SocketException: Permission denied
如果您未授予互联网权限并尝试访问互联网，则会发生这种情况。
答案 1 :(得分：2)
从您的日志显示：
Error in http connection java.net.SocketException: Permission denied
Error converting result java.lang.NullPointerException
Error parsing data org.json.JSONException: End of input at character 0 of
确保您已在清单中提供 INTERNET 权限。
<uses-permission android:name="android.permission.INTERNET" />
还要更改您的适配器方法，如下所示：
@Override
public Object getItem(int position) {
return data.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
答案 2 :(得分：0)
使用此代码块更新解析器
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is, HTTP.UTF_8));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line);
}
is.close();
result = sb.toString();
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}