output: #fixed code
                                  @Override
      public Collection<FileAbstractModel> getFiles(String dir) {
          logger.debug("Listing local files from {}", dir);
          File[] files = new File(dir).listFiles();
          Collection<FileAbstractModel> result;
  
          if (files != null) {
              result = new ArrayList<>(files.length);
  
              // Iterate other files
              for (File file : files) {
                  result.add(toFileAbstractModel(dir, file));
              }
          } else {
              logger.debug("Symlink on windows gives null for listFiles(). Skipping [{}]", dir);
              result = Collections.EMPTY_LIST;
          }
  
  
          logger.debug("{} local files found", result.size());
          return result;
      }
input: #vulnerable code 
                                  @Override
      public Collection<FileAbstractModel> getFiles(String dir) {
          if (logger.isDebugEnabled()) logger.debug("Listing local files from {}", dir);
          File[] files = new File(dir).listFiles();
  
          Collection<FileAbstractModel> result = new ArrayList<>(files.length);
  
          // Iterate other files
          for (File file : files) {
              result.add(toFileAbstractModel(dir, file));
          }
  
          if (logger.isDebugEnabled()) logger.debug("{} local files found", result.size());
          return result;
      } 
                              #location 6 
                              #vulnerability type NULL_DEREFERENCE