Question

I am developing an Android (API level 7) app in Eclipse 3.7.2. I have the most curious problem:

There is a class called LoginData to hold login information:

public class LoginData {
  private final String login;
  private final String password;

  public LoginData(final String login, final String password) {
    this.login = login;                                      // breakpoint 2 here
    this.password = password;
  }

  public String getLogin() {
    return login;
  }
  public String getPassword() {
    return password;
  }
}

Then there is a method to retrieve it (in another class):

public static LoginData getLoginData(final Context context) {
  final SharedPreferences prefs = getPrefs(context);
  final String login = prefs.getString(LOGIN, null);
  final String pass = prefs.getString(PASS, null);
  if (Utils.isEmpty(login) || Utils.isEmpty(pass)) {        // breakpoint 1 here
    return null;
  }
  return new LoginData(login, pass);
}

Method isEmpty() looks like this:

public static boolean isEmpty(final String s) {
  return s == null || "".equals(s);
}

And a method calling getLoginData() inside an AsyncTask:

@Override
protected WSResult doInBackground(final Params... params) {
  final LoginData loginData = Prefs.getLoginData(context);
  ...

context is an activity in which the async task is located.

Now when I run this code, loginData is null. Tracing the problem, I put a breakpoint 1 in the specified location. I see that both login and pass is not empty, and I see the program flow go to the last line, return new LoginData(...);. From there it returns… a null.

Tracing the problem further I add breakpoint 2, only to find that the constructor LoginData(...) does not get invoked.

So my first question is: am I missing something really obvious here? If not, there is some weird problem with the code that gets compiled and run.

Some remarks:

• LoginData is used in another location in the program, and works – breakpoint 2 catches on.
• I tried renaming LoginData to something else, in case it’s cached somewhere or there is a weird name clash.
• I tried running this on a Android 2.1 emulator from Eclipse, as well as on a Galaxy Tab.
• I tried cleaning & building the project again.
• I tried closing & opening the project again.
• I tried deleting the project from workspace and importing it again.

I would like to avoid the necessity to create a new Eclipse workspace (that is my final chance, it helped me in a similar case when dealing with Java EE).

What to do?

Answer 1

if (Utils.isEmpty(login) || Utils.isEmpty(pass))

try replacing this check with

if (login==null || pass==null)