在我的应用程序中，用户必须登录才能访问app.Login详细信息存储在MySQL数据库和php文件中。由于apache服务器已经关闭了应用程序，它在我的logcat中显示了以下详细信息，
[<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
01-17 08:59:01.935: I/tagconvertstr1(1160): <html><head>
01-17 08:59:01.935: I/tagconvertstr1(1160): <title>404 Not Found</title>
01-17 08:59:01.935: I/tagconvertstr1(1160): </head><body>
01-17 08:59:01.935: I/tagconvertstr1(1160): <h1>Not Found</h1>
01-17 08:59:01.935: I/tagconvertstr1(1160): <p>The requested URL /bcreasearchT/Service/loginresponse.php was not found on this server.</p>
01-17 08:59:01.935: I/tagconvertstr1(1160): <hr>
01-17 08:59:01.935: I/tagconvertstr1(1160): <address>Apache/2.2.15 (CentOS) Server at www.medsmonit.com Port 80</address>
01-17 08:59:01.935: I/tagconvertstr1(1160): </body></html>
01-17 08:59:01.935: I/tagconvertstr1(1160): ]
01-17 08:59:01.945: E/JSON Parser(1160): Error parsing data org.json.JSONException: Value <!DOCTYPE of type java.lang.String cannot be converted to JSONObject
01-17 08:59:01.955: I/Choreographer(1160): Skipped 40 frames! The application may be doing too much work on its main thread.
01-17 08:59:01.965: I/tagconvertstr3(1160): [null]
01-17 08:59:01.965: W/dalvikvm(1160): threadid=14: thread exiting with uncaught exception (group=0x40a71930)
01-17 08:59:01.995: I/Choreographer(1160): Skipped 31 frames! The application may be doing too much work on its main thread.
01-17 08:59:02.025: E/AndroidRuntime(1160): FATAL EXCEPTION: AsyncTask #3
01-17 08:59:02.025: E/AndroidRuntime(1160): java.lang.RuntimeException: An error occured while executing doInBackground()
01-17 08:59:02.025: E/AndroidRuntime(1160): at android.os.AsyncTask$3.done(AsyncTask.java:299)
01-17 08:59:02.025: E/AndroidRuntime(1160): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
01-17 08:59:02.025: E/AndroidRuntime(1160): at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
01-17 08:59:02.025: E/AndroidRuntime(1160): at java.util.concurrent.FutureTask.run(FutureTask.java:239)
01-17 08:59:02.025: E/AndroidRuntime(1160): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
01-17 08:59:02.025: E/AndroidRuntime(1160): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
01-17 08:59:02.025: E/AndroidRuntime(1160): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
01-17 08:59:02.025: E/AndroidRuntime(1160): at java.lang.Thread.run(Thread.java:856)
01-17 08:59:02.025: E/AndroidRuntime(1160): Caused by: java.lang.NullPointerException
01-17 08:59:02.025: E/AndroidRuntime(1160): at com.example.sms.LoginActivity$AttemptLogin.doInBackground(LoginActivity.java:280)
01-17 08:59:02.025: E/AndroidRuntime(1160): at com.example.sms.LoginActivity$AttemptLogin.doInBackground(LoginActivity.java:1)
01-17 08:59:02.025: E/AndroidRuntime(1160): at android.os.AsyncTask$2.call(AsyncTask.java:287)
01-17 08:59:02.025: E/AndroidRuntime(1160): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
01-17 08:59:02.025: E/AndroidRuntime(1160): ... 4 more
我怎样才能纠正它？任何人都可以帮助我！
更新：
这是我的aynctask代码，
class AttemptLogin extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
username = (EditText) findViewById(R.id.mobnum);
passw = (EditText) findViewById(R.id.password);
uname = username.getText().toString();
password = passw.getText().toString();
pDialog = new ProgressDialog(LoginActivity.this);
pDialog.setMessage("VALIDATING USER...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected String doInBackground(String... params) {
proInfo.clear();
List<NameValuePair> params1 = new ArrayList<NameValuePair>();
params1.add(new BasicNameValuePair("username", uname));
params1.add(new BasicNameValuePair("pswd", password));
JsonParser jLogin = new JsonParser();
JSONObject json = jLogin.makeHttpRequest(url,"POST", params1);
Log.i("tagconvertstr3", "["+json+"]");
try
{
JSONObject jUser = json.getJSONObject(TAG_SRESL);
userid = jUser.getString(TAG_USERID );
successL = jUser.getString(TAG_SUCCESS1);
proInfo.add(userid);
}
catch(JSONException e)
{
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
if(successL.equalsIgnoreCase("Yes"))
{
usrname=uname;
new ViewProfile().execute();
}
else{
final Dialog dialog = new Dialog(context);
dialog.setContentView(R.layout.custom_dialog);
dialog.setTitle("Login Failed");
dialog.setCancelable(false);
dialog.setCanceledOnTouchOutside(false);
TextView txt = (TextView) dialog.findViewById(R.id.errorlog);
txt.setText("Incorrect username or password!");
Button dialogButton = (Button) dialog.findViewById(R.id.release);
dialogButton.setOnClickListener(new OnClickListener() {
public void onClick(View vd) {
dialog.dismiss();
}
});
dialog.show();
pDialog.dismiss();
}
}
}
这是我的json解析器类，
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
try {
if(method.equalsIgnoreCase("POST")){
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
System.out.println(is);
System.out.println("getting the content");
}else if(method.equalsIgnoreCase("GET")){
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("getting all the values ");
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 {
Log.i("tagconvertstr1", "["+json+"]");
jsonObject = new JSONObject(json);
System.out.println("json object parse finished");
Log.i("tagconvertstr2","["+json+"]");
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
return jsonObject;
}
public JSONObject getJSONFromUrl(String url) {
try {
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 {
Log.i("tagconvertstr", "["+json+"]");
jsonObject = new JSONObject(json);
Log.i("tagconvertstr", "["+json+"]");
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
return jsonObject;
}
答案 0 :(得分：1)
JSONObject jUser = json.getJSONObject(TAG_SRESL);//This is mt 280th line
您的json为空。开始调试。 jLogin.makeHttpRequest(url,"POST", params1);返回null。
同样移动（它更好）
username = (EditText) findViewById(R.id.mobnum);
passw = (EditText) findViewById(R.id.password);
到onCreate
您可以将params直接传递给asynctask doInbackground
new AttemptLogin().execute(username.getText().toString(),passw.getText().toString());
然后在doInbackground（）
中 //String... params
params[0] is username
params[1] is password
你也错过了
@Override
protected void onPostExecute(String file_url) {
super.onPostExecute(file_url);
答案 1 :(得分：0)
我认为您应该检查来自服务器的响应代码并根据该行为进行操作，因为它会导致json创建失败并且可能导致nullpointer。
答案 2 :(得分：0)
使用json对象之前的Kepp条件。替换doInBackground中的代码。
try {
if(json != null){
JSONObject jUser = json.getJSONObject(TAG_SRESL);
userid = jUser.getString(TAG_USERID );
successL = jUser.getString(TAG_SUCCESS1);
proInfo.add(userid);
}
}catch(JSONException e) {
e.printStackTrace();
}
在检查equalsIgnoreCase之前检查此字符串，替换onPostExecute代码。
if(successL != null && successL.equalsIgnoreCase("Yes")) {
usrname=uname;
new ViewProfile().execute();
}
请试试。