Applied patch 3130615: New Rule GuardDebugLogging for jakarta-commons logging. Thanks to Tammo van Lessen.

git-svn-id: https://pmd.svn.sourceforge.net/svnroot/pmd/branches/pmd/4.3.x@7359 51baf565-9d33-0410-a72c-fc3788e3496d

pmd/etc/changelog.txt

@@ -40,6 +40,7 @@ New rule:
 	StrictExceptions : AvoidCatchingGenericException, AvoidLosingExceptionInformation
 	Naming : GenericsNaming
 	JSP: NoInlineScript
+	Logging with Jakarta Commons ruleset: GuardDebugLogging
 
 February 08, 2009 - 4.2.5:
 

pmd/regress/test/net/sourceforge/pmd/rules/loggingjakartacommons/LoggingJakartaCommonsRulesTest.java

@@ -10,6 +10,7 @@ public class LoggingJakartaCommonsRulesTest extends SimpleAggregatorTst {
     public void setUp() {
         addRule("logging-jakarta-commons", "ProperLogger");
         addRule("logging-jakarta-commons", "UseCorrectExceptionLogging");
+        addRule("logging-jakarta-commons", "GuardDebugLogging");
     }
 
     public static junit.framework.Test suite() {

pmd/rulesets/logging-jakarta-commons.xml

@@ -89,5 +89,51 @@ around, with the restriction that the logger needs to be passed into the constru
             </example>
         </rule>
 
+    <rule name="GuardDebugLogging"
+          since="4.3"
+          message="debug logging that involves string concatenation should be guarded with isDebugEnabled() checks"
+          class="net.sourceforge.pmd.rules.XPathRule"
+          externalInfoUrl="http://pmd.sourceforge.net/rules/logging-jakarta-commons.html#GuardDebugLogging">
+        <description>
+            When log messages are composed by concatenating strings, the whole section should be guarded
+            by a isDebugEnabled() check to avoid performance and memory issues.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+            <value>
+            <![CDATA[
+                //PrimaryPrefix[ends-with(Name/@Image, '.debug') and count(../descendant::AdditiveExpression) > 0 and count(ancestor::IfStatement/descendant::PrimaryExpression[ends-with(descendant::PrimaryPrefix/Name/@Image, 'isDebugEnabled')]) = 0]
+            ]]>
+            </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public class Test {
+    private static final Log __log = LogFactory.getLog(Test.class);
+    public void test() {
+        // okay:
+        __log.debug("log something");
+
+        // okay:
+        __log.debug("log something with exception", e);
+
+        // bad:
+        __log.debug("log something" + " and " + "concat strings");
+
+        // bad:
+        __log.debug("log something" + " and " + "concat strings", e);
+
+        // good:
+        if (__log.isDebugEnabled()) {
+        __log.debug("bla" + "",e );
+        }
+    }
+}
+            ]]>
+        </example>
+    </rule>
+
 </ruleset>
 

pmd/xdocs/credits.xml

@@ -321,6 +321,7 @@
             <li>Lucian Ciufudean - RedundantFieldInitializerRule</li>
             <li>Andreas Dangel - GodClass and LawOfDemeter rules, several bugfixes and cleanup</li>
             <li>Riku Nykanen - patch improving TooManyMethods rule</li>
+            <li>Tammo van Lessen - new rule GuardDebugLogging for Jakarta Commons Logging ruleset.</li>
         </ul>
         </subsection>
         <subsection name="Organizations">