我使用下面给出的解析器和Android 2.2示例。我的例子是工作，我没有问题。当试图在使用Android 4.3的项目中使用某些示例时。但我的解析器行有问题
HttpResponse httpResponse = httpClient.execute(httpPost);
我检查了清单中的所有权限，所有权限都已使用。
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
Log.d("test url" , "le request est lancé") ;
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
Log.d("test url" , "la connection etablie");
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;
}
}
日志是：
11-14 10:48:38.590: ERROR/AndroidRuntime(3801): FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{fr.web.tab/fr.web.profilconfiguration.AndroidJSONParsingActivity}: android.os.NetworkOnMainThreadException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
at java.net.InetAddress.lookupHostByName(InetAddress.java:391)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:242)
at java.net.InetAddress.getAllByName(InetAddress.java:220)
at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
at fr.web.profilconfiguration.JSONParser.getJSONFromUrl(JSONParser.java:44)
at fr.web.profilconfiguration.AndroidJSONParsingActivity.onCreate(AndroidJSONParsingActivity.java:62)
at android.app.Activity.performCreate(Activity.java:4465)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
答案 0 :(得分：4)
不要在主线程中使用网络活动。仅针对Honeycomb SDK或更高版本的应用程序抛出此异常。在单独的线程中执行所有与网络相关的任务。你的问题会得到解决。
答案 1 :(得分：2)
Caused by: android.os.NetworkOnMainThreadException
您正在ui线程上运行网络实现操作。
HttpResponse httpResponse = httpClient.execute(httpPost);
上述声明必须位于thread或asynctask doInbackground。
http://developer.android.com/reference/android/os/AsyncTask.html
在ui线程new TheTask().execute()
class TheTask extends AsyncTask<Void ,Void, Void>{
@Override
protected Void doInBackground(Void... params) {
JSONObject jobject =getJSONFromUrl(String url);
return null;
}
}
答案 2 :(得分：1)
Caused by: android.os.NetworkOnMainThreadException
您不能在主线程上使用HttpResponse。您必须使用来自Web的AsyncTask获取Json。
阅读本文;
http://developer.android.com/reference/android/os/AsyncTask.html
答案 3 :(得分：1)
public static JSONObject responseForSignin(final String uname,final String pwd) {
JSONObject jsonResponse = null;
HttpParams httpParameters = new BasicHttpParams();
int connectionTimeout = 1000*12;
int socketTimeout = 1000*13;
HttpConnectionParams.setConnectionTimeout(httpParameters, connectionTimeout);
HttpConnectionParams.setSoTimeout(httpParameters, socketTimeout);
// Create a new HttpClient and Post Header
HttpClient httpClient = new DefaultHttpClient(httpParameters);
HttpPost httpPost = new HttpPost("URL");
httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded");
try {
// Add your data
List<NameValuePair> signinDetails = new ArrayList<NameValuePair>();
signinDetails.add(new BasicNameValuePair("name", uname));
signinDetails.add(new BasicNameValuePair("pwd", pwd));
httpPost.setEntity(new UrlEncodedFormEntity(signinDetails));
// Execute HTTP Post Request
HttpResponse httpResponse = httpClient.execute(httpPost);
Log.v("Post Status", "Code: "+ httpResponse.getStatusLine().getStatusCode());
responseCode = httpResponse.getStatusLine().getStatusCode();
Log.e("responseCode", String.valueOf("response code"+responseCode));
HttpEntity entity = httpResponse.getEntity();
Log.e("entity", String.valueOf(entity));
if (entity != null) {
if (entity != null) {
String responseBody = EntityUtils.toString(entity);
JSONTokener jsonTokener = new JSONTokener(responseBody);
jsonResponse = new JSONObject(jsonTokener);
JSONObject response = jsonResponse.getJSONObject("response");
// Getting String inside response object
String status = response.getString("status");
String message = response.getString("message");
}
} // if (entity != null) end
}
catch (SocketException seExp)
{
}
catch (ConnectTimeoutException cteExp)
{
// TODO Auto-generated catch block
}
catch (ClientProtocolException cpeExp) {
// TODO Auto-generated catch block
}
catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (Exception allExp) {
// TODO Auto-generated catch block
}
return jsonResponse;
}
试试这个
public class RequestLogInFromServer extends AsyncTask<Object, Object, Object>
{
private ProgressDialog progressDialog;
@Override
protected Object doInBackground(Object... params)
{
try {
JSONObject subscriptionResponse = CommonJsonParser.responseForSignin(uname, pwd).getJSONObject("response");
if (!(subscriptionResponse.equals(null))||!(subscriptionResponse.equals(""))) {
}
}
catch (NullPointerException e) {
// TODO Auto-generated catch block
}
catch (JSONException e) {
// TODO Auto-generated catch block
}
catch (Exception e) {
// TODO Auto-generated catch block
}
return null;
}
@Override
protected void onPostExecute(Object result)
{
if(progressDialog!=null){
progressDialog.dismiss();
}
super.onPostExecute(result);
}
@Override
protected void onPreExecute() {
progressDialog = ProgressDialog.show(SignInActivity.this, "", "Please wait");
super.onPreExecute();
}
}
使用AsyncTask.any服务器请求或需要很长时间才能写入后台任务
答案 4 :(得分：1)
你正在主线程中做网络工作，为什么会出现这个错误。 对于开发过程，您可以使用此功能，但不能使用应用程序。
在setcontentView（layout）
之后将此代码放在oncreate方法的Activity中if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
}