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Error Class Java.lang.nullpointerexception

Reinstalling Windows will erase everything from your hard drive, allowing you to start again with a fresh system. While holding CTRL-Shift on your keyboard, hit ENTER. Unfortunately it is possible to call the method like this: doSomething(null); in which case obj is null. share answered Jun 25 '14 at 11:17 L. his comment is here

Follow the steps in the Wizard to choose a restore point. Sometimes resolving your Runtime Errors problems may be as simple as updating Windows with the latest Service Pack or other patch that Microsoft releases on an ongoing basis. Instructions for Windows XP: Open Programs and Features by clicking the Start button. Another program maliciously or mistakenly deleted Java-related files.

Please include a SSCCE if you want any help. As a Gold Certified Independent Software Vendor (ISV), Solvusoft is able to provide the highest level of customer satisfaction through delivering top-level software and service solutions, which have been subject to There are also conditional breakpoints you can use which will tell you when a value changes. –fgb Dec 10 '15 at 11:33 | show 1 more comment up vote 135 down but that's not happening here.) So what about our 2nd scenario?

The first "at" line would say that the exception was thrown in some line in the java.lang.String class, and line 4 of Test.java would be the second "at" line. I have been researching the topic for a while now, but can find nothing. We start by looking at the line that the stacktrace has told us is where the NPE happened: int length = foo.length(); // HERE How can that throw an NPE? You can now reference the object using the dereferencing operator . (a dot).

And we can see clearly that we initialized foo to a non-null value. There is no way we can work with it, so this object is marked for to be garbage collected, and at some point the VM will free the memory used by If the method was called, make sure to check the order that these methods are called, and the set method isn't called after the print method. Also, try simplifying the code first (see SSCCE).

We do not claim any responsibility for the results of the actions taken from the content linked below - complete these tasks at your own risk. The problem in the program is NOT a compilation error. This results in a NullPointerException because there is no code to execute in the location that the reference is pointing. (This is a technicality, but I think it bears mentioning: A After you have successfully uninstalled your Error 500 java.lang.nullpointerexception-associated program (eg.

Take this example: public class Some { private int id; public int getId(){ return this.id; } public setId( int newId ) { this.id = newId; } } .... .... // Somewhere https://teamtreehouse.com/community/how-to-fix-javalangnullpointerexception It is what you >>do<< with the uninitialized attribute value that causes the NPE. –Stephen C May 19 at 6:57 1 This is from docs.oracle.com/javase/8/docs/api/java/lang/…. -1 for quoting without reference. See vogella.com/tutorials/EclipseDebugging/article.html for example. –fgb Dec 10 '15 at 10:22 2 @fgb Yes, I've used one before to check memory spikes...But how do you use them to check for null Step 7: Run Windows System File Checker ("sfc /scannow") System File Checker is a handy tool included with Windows that allows you scan for and restore corruptions in Windows system files

In the posted example there is only one expression that can meet this requirement. (Hint: what does the compiler variable evaluate to?) –user166390 May 5 '12 at 18:09 15 Relax, http://oncarecrm.com/error-class/error-class-java.html Please simply copy/paste and run the program with the IDE of your choice (Eclipse IDE was used for this example). at Test.main(Test.java:4) This tells us a number of things: "at Test.main" says that we were in the main method of the Test class. "Test.java:4" gives the source filename of the class, Caution: Unless you an advanced PC user, we DO NOT recommend editing the Windows registry manually.

How do I fix it? These malicious intruders can damage, corrupt, or even delete Runtime Errors-related files. Well if that happened, the stacktrace would look different. weblink Thanks.

Why don't you connect unused hot and neutral wires to "complete the circuit"? In fact, there are two ways: If the value of bar is null then bar[pos] will throw an NPE. In fact there is only one way: it can only happen if foo has the value null.


This can potentially help you avoid hours of troubleshooting headaches associated with 500 java.lang.nullpointerexception errors. Drivers can work one day, and suddenly stop working the next day, for a variety of reasons. Click on the Java-associated entry. Virus or malware infection that has corrupted Windows system files or Java-related program files.

Recommendation: Scan your PC for computer errors. In the Export Range box, be sure that "Selected branch" is selected. Draw an asterisk triangle Can 'it' be used to refer to a person? http://oncarecrm.com/error-class/error-class-java-6.html When p is a null pointer, the location stored in "p" is "nowhere", you're saying "give me the data at the location 'nowhere'".