我正在尝试为Android设备设置注册过程。用户应该打开应用程序，输入详细信息并存储在数据库中。
按照目前的情况，用户可以正常输入数据库，但是logcat在将字符串数据转换为JSON时遇到了问题。
这可以告诉我什么来自哪里？
public class RegisterTask extends AsyncTask<String, Void, Integer> {
private ProgressDialog progressDialog;
private RegisterActivity activity;
private int id = -1;
private JSONParser jsonParser;
private static String loginURL = "http://***.***.**.**/androidUsers/";
private static String registerURL = "http://***.***.**.**/androidUsers/";
private static String KEY_SUCCESS = "success";
private static String KEY_ERROR = "error";
private static String KEY_ERROR_MSG = "error_msg";
private static String KEY_UID = "uid";
private static String KEY_NAME = "name";
private static String KEY_EMAIL = "email";
private static String KEY_CREATED_AT = "created_at";
private int responseCode = 0;
/*Constructor that takes parameters passed by LoginFragment and stores them as class-
* wide fields so that all methods can access necessary variables.
* */
public RegisterTask(RegisterActivity activity, ProgressDialog progressDialog)
{
this.activity = activity;
this.progressDialog = progressDialog;
}
/*A necessary but very simple method that launches a ProgressDialog to show the
* user that a background task is operating (registration).*/
@Override
protected void onPreExecute()
{
progressDialog.show();
}
/*This method does almost all of the work for the class. It builds a connection to my
* server, collects the details from the UI of the user's information, and then tries
* to register the user with the SQL database. All of the actual HTTP connection work
* is done in a background library class for security - including the hashing of a
* password into a 64bit encryption. */
@Override
protected Integer doInBackground(String... arg0)
{
EditText userName = (EditText)activity.findViewById(R.id.registerEmail);
EditText passwordEdit = (EditText)activity.findViewById(R.id.registerPassword);
EditText nameEdit = (EditText)activity.findViewById(R.id.registerName);
String name = nameEdit.getText().toString();
String email = userName.getText().toString();
String password = passwordEdit.getText().toString();
Log.v(email, password);
UserFunctions userFunction = new UserFunctions();
JSONObject json = userFunction.registerUser(name, email, password);
// check for login response
try
{
if (json.getString(KEY_SUCCESS) != null)
{
//registerErrorMsg.setText("");
String res = json.getString(KEY_SUCCESS);
if(Integer.parseInt(res) == 1){
// user successfully registred
// Store user details in SQLite Database
DatabaseHandler db = new DatabaseHandler(activity.getApplicationContext());
JSONObject json_user = json.getJSONObject("user");
// Clear all previous data in database
userFunction.logoutUser(activity.getApplicationContext());
db.addUser(json_user.getString(KEY_NAME),
json_user.getString(KEY_EMAIL), json.getString(KEY_UID),
json_user.getString(KEY_CREATED_AT));
//successful registration
responseCode = 1;
}else{
// Error in registration
responseCode = 0;
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return responseCode;
}
/*This final method concludes the background task. Its responseCode variable is sent from
* doInBackground, and this method acts based on the code it is sent. If the code is 1,
* registration was successful and the main activity notifies the user of succes - the
* inverse occurs if there is a failure and 0 was sent.*/
@Override
protected void onPostExecute(Integer responseCode)
{
EditText userName = (EditText)activity.findViewById(R.id.registerEmail);
EditText passwordEdit = (EditText)activity.findViewById(R.id.registerPassword);
String s = userName.getText().toString();
if (responseCode == 1) {
progressDialog.dismiss();
activity.registerReport(responseCode);
userName.setText("");
passwordEdit.setText("");
}
if (responseCode == 0) {
progressDialog.dismiss();
activity.registerReport(responseCode);
}
}
}
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url, List<NameValuePair> params) {
// Making HTTP request
try {
// defaultHttpClient
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();
} 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();
Log.e("JSON", json);
} 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) { //this is where the error results
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
20:35:56.346 11989-12390/com.example.jay.demoapp E/JSON﹕ Connected successfully{"tag":"register","success":1,"error":0,"uid":"5519a59d377a95.73943916","user":{"name":"testname","email":"testemail@test.com","created_at":"2015-03-30 20:35:57","updated_at":null}}
03-30 20:35:56.361 11989-12390/com.example.jay.demoapp E/JSON Parser﹕ Error parsing data org.json.JSONException: Value Connected of type java.lang.String cannot be converted to JSONObject
03-30 20:35:56.361 11989-12390/com.example.jay.demoapp W/dalvikvm﹕ threadid=12: thread exiting with uncaught exception (group=0x412bd2a0)
03-30 20:35:56.396 11989-12390/com.example.jay.demoapp E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:299)
at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
at java.util.concurrent.FutureTask.run(FutureTask.java:137)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
at java.lang.Thread.run(Thread.java:856)
Caused by: java.lang.NullPointerException
at com.example.jay.demoapp.RegisterTask.doInBackground(RegisterTask.java:76)
at com.example.jay.demoapp.RegisterTask.doInBackground(RegisterTask.java:18)
at android.os.AsyncTask$2.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
at java.util.concurrent.FutureTask.run(FutureTask.java:137)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
at java.lang.Thread.run(Thread.java:856)
03-30 20:36:05.346 11989-11989/com.example.jay.demoapp I/Choreographer﹕ Skipped 527 frames! The application may be doing too much work on its main thread.
03-30 20:36:05.916 11989-11989/com.example.jay.demoapp E/WindowManager﹕ Activity com.example.jay.demoapp.RegisterActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@41d7c868 that was originally added here
android.view.WindowLeaked: Activity com.example.jay.demoapp.RegisterActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@41d7c868 that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:403)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:311)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:224)
at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:149)
at android.view.Window$LocalWindowManager.addView(Window.java:554)
at android.app.Dialog.show(Dialog.java:277)
at com.example.jay.demoapp.RegisterTask.onPreExecute(RegisterTask.java:49)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
at android.os.AsyncTask.execute(AsyncTask.java:534)
at com.example.jay.demoapp.RegisterActivity$1.onClick(RegisterActivity.java:52)
at android.view.View.performClick(View.java:4232)
at android.view.View$PerformClick.run(View.java:17298)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4921)
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:1027)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
at dalvik.system.NativeStart.main(Native Method)
正如我之前所说，数据将没有问题到达数据库并存储用户，但我无法登录我认为是由上述错误引起的数据。
添加了JSONParser类，因为错误似乎来自最后一个try-catch块
答案 0 :(得分：1)
我认为你忽略了（我乍看之下）实际的问题，因为你沉默了你所得到的JSONException：
try {
jObj = new JSONObject(json);
} catch (JSONException e) { //this is where the error results
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
服务器在实际JSON响应之前发送字符串Connected successfully ：
Connected successfully{...}
这会在您的日志输出中显示。因此，您的JSON解析失败，导致getJSONFromUrl()返回null。
该行
if (json.getString(KEY_SUCCESS) != null)
因失败的解析而导致NullPointerException失败，因为json为null。
建议的解决方案：检查服务器端代码并删除服务器发送给您的Connected successfully。