package com.github.searls.jasmine.mojo;
   
   import org.apache.maven.plugin.MojoExecutionException;
   import org.apache.maven.project.MavenProject;
   import org.codehaus.plexus.resource.ResourceManager;
   import org.codehaus.plexus.resource.loader.FileResourceLoader;
   
   import java.io.File;
   
  public class ResourceRetriever {
  
    private final ResourceManager locator;
  
    private static final String ERROR_FILE_DNE = "Invalid value for parameter '%s'. File does not exist: %s";
  
    public ResourceRetriever(final ResourceManager locator) {
      this.locator = locator;
    }
  
    public File getResourceAsFile(final String parameter, final String resourceLocation, final MavenProject mavenProject) throws MojoExecutionException {
      File file = null;
  
      if (resourceLocation != null) {
        locator.addSearchPath("url", "");
        locator.addSearchPath(FileResourceLoader.ID, mavenProject.getFile().getParentFile().getAbsolutePath());
  
        ClassLoader origLoader = Thread.currentThread().getContextClassLoader();
        try {
          Thread.currentThread().setContextClassLoader(getClass().getClassLoader());
          try {
            file = locator.getResourceAsFile(resourceLocation);
          } catch (Exception e) {
            throw new MojoExecutionException(String.format(ERROR_FILE_DNE, parameter, resourceLocation));
          }
        } finally {
          Thread.currentThread().setContextClassLoader(origLoader);
        }
      }
      return file;
    }
  }