Cannot compile example java rule file

[Jimmy Philps]

I am trying to follow the instructions for making a custom rule via Java (not XPath). The end result is as follows:

import net.sourceforge.pmd.lang.java.rule.*;
import net.sourceforge.pmd.lang.java.ast.*;
public class WhileLoopsMustUseBracesRule extends AbstractJavaRule {
public Object visit(ASTWhileStatement node, Object data) {
System.out.println("hello world");
return data;
}
}

So when I try to compile using the following command:

javac -cp lib/pmd-java-5.3.2.jar WhileLoopsMustUseBracesRule.java

The error message I receive is as follows:

WhileLoopsMustUseBracesRule.java:3: error: cannot access ImmutableLanguage
public class WhileLoopsMustUseBracesRule extends AbstractJavaRule {
^
class file for net.sourceforge.pmd.lang.rule.ImmutableLanguage not found
1 error

NOTE: That arrow is actually aiming at the "class" part not "public"

So I am trying to figure out how to compile this without errors so that my custom ruleset will recognize this as a valid class. (currently it says "Couldn't find the class WhileLoopsMustUseBracesRule").

Any help is appreciated, thanks!

[Andreas Dangel]

You'll need to add all jar files to the classpath while compiling. You can do this simply by this command:

javac -cp lib/* WhileLoopsMustUseBracesRule.java

Update: See below

Then it should work :)

[Andreas Dangel]

Correction: the asterisk (*) must be in quotes, otherwise your shell will expand it, so the correct command is:

javac -cp 'lib/*' WhileLoopsMustUseBracesRule.java

[Jimmy Philps]

Awesome, thanks for the response!

One last issue is that when I run that javac -cp lib/* WhileLoopsMustUseBracesRule.java I get this error message:

javac: invalid flag: lib/asm-5.0.3.jar
Usage: javac <options>
use -help for a list of possible options</options>

asm-5.0.3.jar is the second item in that lib subdirectory, so I think that it is reading in the subsequent filenames in lib as additional parameters for some reason...

So I guess what I am asking is, is lib/* the proper way to include multiple <options> files? </options>

Also I realize this is more of a java compiling question so I apologize if it is wasting your time.

[Jimmy Philps]

Actually, I have resolved that issue. I just needed to escape the asterisk. So I used the following instead:

javac -cp lib/\* WhileLoopsMustUseBracesRule.java

But thanks for all your help!

[Azadeh]

Hi, I did this steps, but when I run this script I got a new error:

C:\Ph.D\IdentifierName\Workspace\Azadeh\src\WhileLoopsMustUseBracesRule.java:1: error: package net.sourceforge.pmd.lang.java.rule does not exist
import net.sourceforge.pmd.lang.java.rule.;
^
C:\Ph.D\IdentifierName\Workspace\Azadeh\src\WhileLoopsMustUseBracesRule.java:2: error: package net.sourceforge.pmd.lang.java.ast does not exist
import net.sourceforge.pmd.lang.java.ast.;
^
C:\Ph.D\IdentifierName\Workspace\Azadeh\src\WhileLoopsMustUseBracesRule.java:4: error: cannot find symbol
public class WhileLoopsMustUseBracesRule extends AbstractJavaRule {
^
symbol: class AbstractJavaRule
C:\Ph.D\IdentifierName\Workspace\Azadeh\src\WhileLoopsMustUseBracesRule.java:5: error: cannot find symbol
public Object visit(ASTWhileStatement node, Object data) {
^
symbol: class ASTWhileStatement
location: class WhileLoopsMustUseBracesRule
4 errors

[Suman alungh]

@Azadeh, Were you able to get rid of these errors? I'm getting the same

[Andreas Dangel]

Hi all,
sorry for the late response.
I've now created two sample projects, of how to build a custom rule:
See https://github.com/pmd/pmd-examples
Let me know, how we can improve such guides.
Regards,
Andreas