Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>I would try Findbugs and PMD. If neither of those detect the bug, the next thing to try would be to see if you could create a custom PMD checker that would detect this.</p> <p>Actually, statically detecting cases where a reference field is used before before it is initialized is likely to be difficult. I have a feeling that your example is one of the few cases that might be tractable. Consider this variation for example:</p> <pre><code>public class SettingsActivity extends PreferenceActivity { private String mTest; @Override protected void onPostCreate(Bundle savedInstanceState) { super.onPostCreate(savedInstanceState); mTest.replace("a", "b"); } public void setTest(String test) { mTest = testl; } } </code></pre> <p>Determining whether the suspect line could result in an NPE requires an analysis of the code base to see is <code>setTest</code> is ever called. And even then, you've only determined that an NPE <em>may</em> not occur ... not that it <em>will</em> not occur.</p> <hr> <p>References:</p> <ul> <li><a href="https://stackoverflow.com/questions/6724627/is-there-any-tools-for-finding-null-pointer-exception-in-java-files">Is there any tools for finding Null pointer exception in java files..?</a></li> <li><a href="https://stackoverflow.com/questions/2794928/npe-annotation-scenarios-and-static-analysis-tools-for-java">NPE annotation scenarios and static-analysis tools for Java</a> - which talks about a different, but related problem.</li> <li><a href="http://www.codeproject.com/Articles/26224/Static-Analysis-on-Steroids-Parasoft-BugDetective" rel="nofollow noreferrer">http://www.codeproject.com/Articles/26224/Static-Analysis-on-Steroids-Parasoft-BugDetective</a> - BugDetective uses flow analysis which is more likely to find problems with uninitialized variables.</li> </ul>
    singulars
    1. This table or related slice is empty.
    1. POIs there any tool for detecting possible NullPointerException in class member variable
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USCommunity
    1. USStephen C
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. COYes, it seems this NPE is difficult for Findbugs and PMD to analyse at this moment.
      singulars
      1. PO
      1. USneo
    2. CO@neo.orz.hk - The issue is actually broader than NPEs. The problem is that finding bugs of this nature involves 1) global analysis, 2) analysis of control flows to determine (in this case) whether one event can happen before another one. By contrast, Findbugs and PMD are limited to looking for suspicious patterns in the code structure.
      singulars
      1. PO
      1. USStephen C
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload