Added AvoidLosingExceptionInformation from George Thomas.

git-svn-id: https://pmd.svn.sourceforge.net/svnroot/pmd/branches/pmd/4.2.x@6972 51baf565-9d33-0410-a72c-fc3788e3496d

pmd/etc/changelog.txt

@@ -15,7 +15,7 @@ Android ruleset: CallSuperLast rule now also checks for finish() redefinitions
 New rule:
 	Android: DoNotHardCodeSDCard
 	Controversial : AvoidLiteralsInIfCondition (patch 2591627)
-	StrictExceptions : AvoidCatchingGenericException
+	StrictExceptions : AvoidCatchingGenericException, AvoidLosingExceptionInformation
 
 February 08, 2009 - 4.2.5:
 

pmd/regress/test/net/sourceforge/pmd/rules/strictexception/StrictExceptionRulesTest.java

@@ -11,6 +11,7 @@ public class StrictExceptionRulesTest extends SimpleAggregatorTst {
         addRule("strictexception", "AvoidCatchingGenericException");
         addRule("strictexception", "AvoidCatchingNPE");
         addRule("strictexception", "AvoidCatchingThrowable");
+        addRule("strictexception", "AvoidLosingExceptionInformation");
         addRule("strictexception", "AvoidRethrowingException");
         addRule("strictexception", "AvoidThrowingNewInstanceOfSameException");
         addRule("strictexception", "AvoidThrowingNullPointerException");

pmd/regress/test/net/sourceforge/pmd/rules/strictexception/xml/AvoidLosingExceptionInformation.xml

@@ -0,0 +1,100 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<test-data>
+ <test-code>
+  <description><![CDATA[
+basic failure case
+     ]]></description>
+  <expected-problems>1</expected-problems>
+  <code><![CDATA[
+public class Foo {
+  void bar() {
+   try {
+   } catch (SomeException se) {
+     se.getMessage();
+   }
+  }
+}
+     ]]></code>
+ </test-code>
+ <test-code>
+  <description><![CDATA[
+fetch the value returned by getMessage(), ok
+     ]]></description>
+  <expected-problems>0</expected-problems>
+  <code><![CDATA[
+public class Foo {
+  void bar() {
+   try {
+   } catch (SomeException se) {
+     String msg = se.getMessage();
+   }
+  }
+}
+     ]]></code>
+ </test-code>
+ <test-code>
+  <description><![CDATA[
+fetch the value returned by getCause(), ok
+     ]]></description>
+  <expected-problems>0</expected-problems>
+  <code><![CDATA[
+public class Foo {
+  void bar() {
+   try {
+   } catch (SomeException se) {
+     Throwable t = se.getCause();
+   }
+  }
+}
+     ]]></code>
+ </test-code>
+ <test-code>
+  <description><![CDATA[
+a mix of guilty calls to getMessage(), getLocalizedMessage(), getCause() or getStackTrace(), failure
+     ]]></description>
+  <expected-problems>2</expected-problems>
+  <code><![CDATA[
+  public class Foo {
+   void bar() {
+    try {
+    // do something
+    }  catch (SomeException se) {
+       se.printStackTrace();
+      System.out.println("boo");
+      long l = 1L + 4L;
+      se.getMessage();
+      int a = 1;
+     se.getMessage();
+    }
+   }
+  }
+     ]]></code>
+ </test-code>
+ <test-code>
+  <description><![CDATA[
+a larger mix of guilty calls to getMessage(), getLocalizedMessage(), getCause(), getStackTrace() or toString(), failure
+     ]]></description>
+  <expected-problems>5</expected-problems>
+  <code><![CDATA[
+  public class Foo {
+   void bar() {
+    try {
+    // do something
+    }  catch (SomeException se) {
+       se.printStackTrace();
+      System.out.println("boo");
+      int i = 1;
+      se.getLocalizedMessage();
+      long l = 1L + 4L;
+      se.getMessage();
+      int a = 1;
+      se.toString();
+     se.getMessage();
+     System.out.println("far");
+     se.getStackTrace();
+    }
+   }
+  }
+     ]]></code>
+ </test-code> 
+</test-data>

pmd/rulesets/strictexception.xml

@@ -373,5 +373,48 @@ public class PrimitiveType {
     </example>
   </rule>
 
+	<rule name="AvoidLosingExceptionInformation"
+		since="4.2.6"
+		message="Avoid statements in a catch block that invoke accessors on the exception without using the information"
+		externalInfoUrl="http://pmd.sourceforge.net/rules/strictexception.html#AvoidLosingExceptionInformation"
+		class="net.sourceforge.pmd.rules.XPathRule">
+		<description>Statements in a catch block that invoke accessors on the exception without using the information
+		only add to code size.  Either remove the invocation, or use the return result.</description>
+		<priority>2</priority>
+		<properties>
+			<property name="xpath">
+				<value>
+<![CDATA[
+//CatchStatement/Block/BlockStatement/Statement/StatementExpression/PrimaryExpression/PrimaryPrefix/Name
+[
+   @Image = concat(../../../../../../../FormalParameter/VariableDeclaratorId/@Image, '.getMessage')
+   or
+   @Image = concat(../../../../../../../FormalParameter/VariableDeclaratorId/@Image, '.getLocalizedMessage')
+   or
+   @Image = concat(../../../../../../../FormalParameter/VariableDeclaratorId/@Image, '.getCause')
+   or
+   @Image = concat(../../../../../../../FormalParameter/VariableDeclaratorId/@Image, '.getStackTrace')
+   or
+   @Image = concat(../../../../../../../FormalParameter/VariableDeclaratorId/@Image, '.toString')
+]
+]]>
+				</value>
+			</property>
+		</properties>
+		<example>
+<![CDATA[
+public class Foo {
+ void bar() {
+  try {
+   // do something
+  } catch (SomeException se) {
+    se.getMessage();
+  }
+ }
+}
+]]>
+		</example>
+	</rule>
+
 </ruleset>
 

pmd/xdocs/credits.xml

@@ -86,7 +86,7 @@
             <li>Peter Van de Voorde - Rewrote the 'create rule XML' functionality in the designer utility</li>
             <li>Josh Devins - Reported bug with annotation parsing</li>
             <li>Alan Berg - Reported bug in Ant task</li>
-            <li>George Thomas - Wrote AvoidRethrowingException rule</li>
+            <li>George Thomas - Wrote AvoidRethrowingException rule, new AvoidLosingExceptionInformation rule</li>
             <li>Robert Simmons - Reported bug in optimizations package along with suggestions for fix</li>
             <li>Brian Remedios - display cleanup of CPD GUI, code cleanup of StringUtil and various rules, cleanup of rule designer, code cleanup of net.sourceforge.pmd.ant.Formatter.java, code improvements to Eclipse plugin, created AbstractPoorMethodCall and refactored UseIndexOfChar</li>
             <li>Max Tardiveau - A nice XML to HTML stylesheet for CPD.</li>