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teaching:labs:mdse:2013:bug_descriptions:jt-bug-cor103 [2013/10/14 10:05]
jaspreet_kaur
teaching:labs:mdse:2013:bug_descriptions:jt-bug-cor103 [2018/05/09 01:59] (current)
Line 1: Line 1:
 +====== Bug JT_Category_Number ======
  
 +===== Inspired by =====
 +
 +  * [[http://​findbugs.sourceforge.net/​bugDescriptions.html#​RE_BAD_SYNTAX_FOR_REGULAR_EXPRESSION | RE_BAD_SYNTAX_FOR_REGULAR_EXPRESSION]]
 +
 +===== Original Description =====
 +
 +The code here uses a regular expression that is invalid according to the syntax for regular expressions. This statement will throw a PatternSyntaxException when executed. -- 2013-10-14 ​
 +
 +
 +===== Detailed Description =====
 +
 +Syntax errors also called as parsing errors, are caught by ParseSyntaxException in Java whenever incorrect syntax is passed in any regular expression.
 +
 +===== Sample Problem Scenario =====
 +<code Java>
 +public class PatternExample {
 + public static void main(String[] args) {
 + Pattern pattern = Pattern.compile('​.xx.'​);​
 + Matcher matcher = pattern.matcher('​MxxY'​);​
 + System.out.println('​Input String matches regex - '​+matcher.matches());​
 + // bad regular expression
 + pattern = Pattern.compile('​*xx*'​);​
 + }
 +}
 +</​Code>​
 +
 +===== Sample Fix =====
 +<code Java>
 +String str = '​bbb';​
 +System.out.println('​Using String matches method: '​+str.matches('​.bb'​));​
 +System.out.println('​Using Pattern matches method: '​+Pattern.matches('​.bb',​ str));
 +</​Code>​
 +
 +===== Evaluation Results =====
 +
 +^  Benchmark project ​ ^  Precision ​             ^^^  Recall ​               ^^^
 +|                     ​| ​ FB    |  JT    |  Delta  |  FB    |  JT    |  Delta |
 +|  Project ...        |  ...%  |  ...%  |  ...%   ​| ​ ...%  |  ...%  |  ...%  |  ​
 +|  Project ...        |  ...%  |  ...%  |  ...%   ​| ​ ...%  |  ...%  |  ...%  |   
 +FB = FindBugs, JT = JTransformer,​ Delta = JTransformer - FindBugs
 + 
teaching/labs/mdse/2013/bug_descriptions/jt-bug-cor103.txt · Last modified: 2018/05/09 01:59 (external edit)

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