CODEWITHSUNDEEP
javaexceptionloggingruntime-error
user2385057
user2385057

Reputation: 537

Capture Run Time Errors Java

I am sure this must have been asked earlier, but I couldn't search the post.

I want to capture run time errors generated by thread with native java libraries, what methods can I use to do same ?

Here's an example of error :

Exception in thread "main" java.io.FileNotFoundException: C:\Documents and Settings\All Users\Application Data\CR2\Bwac\Database\BWC_EJournal.mdb (The system cannot find the path specified)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(FileInputStream.java:106)
    at java.io.FileInputStream.<init>(FileInputStream.java:66)
    at CopyEJ.CopyEJ.main(CopyEJ.java:91)

I want to log this error in file to be reviewed later

Upvotes: 1

Views: 1163

Answers (4)

KhAn SaAb
KhAn SaAb

Reputation: 5366

its good practices use try catch and finally

try {
     //Your code goes here    

 } catch (Exception e) {
    //handle exceptions over here
} finally{
   //close your open connections
}

Upvotes: 1

Sergey Makarov
Sergey Makarov

Reputation: 2531

Thread class has 'uncaught exception handler' - see http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html#setUncaughtExceptionHandler%28java.lang.Thread.UncaughtExceptionHandler%29. It allows you to delegate exception handling to somewhere outside of your thread, so you don't need to put try-catch in your run() method implementation.

Upvotes: 2

Timmetje
Timmetje

Reputation: 7694

You can catch errors with the try block.

Example

try {
    // some i/o function
    reader = new BufferedReader(new FileReader(file));

} catch (FileNotFoundException e) {
    // catch the error , you can log these
    e.printStackTrace();

} catch (IOException e) {
    // catch the error , you can log these
   e.printStackTrace();
}

Java Tutorials- Lesson: Exceptions

Upvotes: 1

Jon Skeet
Jon Skeet

Reputation: 1499860

Just catch the exception! My guess is that currently your main method is declared to throw Exception, and you're not catching anything... so the exception is just propagating out of main. Just catch the exception:

try {
    // Do some operations which might throw an exception
} catch (FileNotFoundException e) {
    // Handle the exception however you want, e.g. logging.
    // You may want to rethrow the exception afterwards...
}

See the exceptions part of the Java tutorial for more information about exceptions.

The fact that the exception came up in native code is irrelevant here - it's propagated in a perfectly normal way.

Upvotes: 4

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