Source line number in exception trace

Question

Excuse me if the question is silly.
When I print the stack trace after an exception has occured, how is it able to display the exact source line number 'cos the source file may or may not be accessible to the jvm. Obviously they don't keep source line-wise info in the class file,right?

Answer 1

won't class files be large just because of the debug data?
laurivasko@linux:~/java> javac HelloWorld.java
laurivasko@linux:~/java> ls -la HelloWorld.class
-rw-r--r--    1 laurivasko users         426 2004-06-26 20:07 HelloWorld.class
laurivasko@linux:~/java> javac -g:none HelloWorld.java
laurivasko@linux:~/java> ls -la HelloWorld.class
-rw-r--r--    1 laurivasko users         341 2004-06-26 20:07 HelloWorld.classas you see, first case has file size of 426 bytes, and other one has wile size of 341 bytes, and that all with 5 line HelloWorld commandline application.
// hopefully that answers your question.