Question

I have a source folder with Java source files. These Java files have different packages. Using javac command I can generate the package structure, but the packages will contain the class files not the source files.

Is there any API which generates package structure from Java files and puts Java files into the specific package

Answer 1

Here’s what I came up for this problem.It opens the java file, reads the package name, generates the structure and copies the file to that structure. Suggestions for improvement are welcome. 🙂

public final class FileListing {

private Map packageMap;


public void createPackageStructure(String sourceDir) throws FileNotFoundException 
{
    FileListing fileListing = new FileListing();
File startingDirectory= new File(sourceDir);

    fileListing.packageMap = new HashMap();
    List<File> files = fileListing.getFileListing(startingDirectory,   fileListing.getPackageMap());

    fileListing.moveFiles(fileListing.packageMap);

}


public List<File> getFileListing(File aStartingDir, Map packageMap) throws   FileNotFoundException 
{
    validateDirectory(aStartingDir);
    List<File> result = getFileListingNoSort(aStartingDir,packageMap);
    Collections.sort(result);
    return result;
}


private List<File> getFileListingNoSort(File aStartingDir, Map packageMap) throws FileNotFoundException 
{  
    List<File> result = new ArrayList<File>();
    File[] filesAndDirs = aStartingDir.listFiles();
    List<File> filesDirs = Arrays.asList(filesAndDirs);

    for(File file : filesDirs) 
    {
       result.add(file); 
       if(file.isFile())
       {
           packageMap.put(file, readPackageName(file.getAbsolutePath()).replace(".", "/").replace(";", "/"));
       }
       else 
       {
           //must be a directory
           //recursive call!
           List<File> deeperList = getFileListingNoSort(file,packageMap);
           result.addAll(deeperList);
       }
    }
return result;
}

public String readPackageName(String filePath)
{
  String packageName=null;
  String line;
  String temp[] = new String[2];
  BufferedReader br=null;
  try{
      File javaFile =  new File(filePath);
      br = new BufferedReader(new FileReader(javaFile));
      while((line=br.readLine())!=null)
      {
          if(line.indexOf("package")!=-1)
          {
              temp = line.split(" ");
              break;
          }
      }
      br.close();

  }catch(FileNotFoundException fnfe)
  {
      fnfe.printStackTrace();
  }catch(IOException ioe)
  {
      ioe.printStackTrace();
  }
  return temp[1];
}

public void moveFiles(Map packageMap)
{
 Set keySet = packageMap.keySet();
 Iterator it = keySet.iterator();
     File sourceFile, destFile, destDirs;
 InputStream in = null;
 OutputStream out = null;
 byte[] buf = new byte[1024];
 int len;

     try{
     while(it.hasNext())
         {
        sourceFile = (File)it.next();
        destDirs = new File("src/"+(String)packageMap.get(sourceFile));
        destFile = new File("src/"+   (String)packageMap.get(sourceFile)+"/"+sourceFile.getName());
        destDirs.mkdirs();
        in = new FileInputStream(sourceFile);
        out = new FileOutputStream(destFile);

        while((len = in.read(buf)) > 0){
            out.write(buf, 0, len);
        }
         }
   }catch(FileNotFoundException fnfe)
   {
       fnfe.printStackTrace();
   }catch(IOException ioe)
   {
       ioe.printStackTrace();
   }
}

static private void validateDirectory (File aDirectory) throws FileNotFoundException 
{
  if (aDirectory == null) {
    throw new IllegalArgumentException("Directory should not be null.");
  }
  if (!aDirectory.exists()) {
    throw new FileNotFoundException("Directory does not exist: " + aDirectory);
  }
  if (!aDirectory.isDirectory()) {
    throw new IllegalArgumentException("Is not a directory: " + aDirectory);
  }
  if (!aDirectory.canRead()) {
    throw new IllegalArgumentException("Directory cannot be read: " + aDirectory);
  }
}

public Map getPackageMap()
{
  return this.packageMap;
}
}