Maven: add a folder or jar file into current classpath

Question

I am using maven-compile plugin to compile classes. Now I would like to add one jar file into the current classpath. That file stays in another location (let\'s say c:/jars/

Answer 1

From docs and example it is not clear that classpath manipulation is not allowed.

 
  classpath=${basedir}/lib/bad.jar
 

But see Java docs (also https://www.cis.upenn.edu/~bcpierce/courses/629/jdkdocs/tooldocs/solaris/javac.html)

-classpath path Specifies the path javac uses to look up classes needed to run javac or being referenced by other classes you are compiling. Overrides the default or the CLASSPATH environment variable if it is set.

Maybe it is possible to get current classpath and extend it,
see in maven, how output the classpath being used?

    
      cp.txt
    

  
    org.apache.maven.plugins
    maven-dependency-plugin
    2.9
    
      
        build-classpath
        generate-sources
        
          build-classpath
        
        
          ${cpfile}
        
      
    
  

Read file (Read a file into a Maven property)

  org.codehaus.gmaven
  gmaven-plugin
  1.4
  
    
      generate-resources
      
        execute
      
      
        
          def file = new File(project.properties.cpfile)
          project.properties.cp = file.getText()
        
      
    
  

and finally

  
    org.apache.maven.plugins
    maven-compiler-plugin
    3.6.1
    
      
         classpath=${cp}:${basedir}/lib/bad.jar