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Recursive file search

I am trying to find a file in the root directory and its subdirectories.

Step1 - find the directory at the specified path. Step 2. If the directory found above is found, find the file in one of the subdirectories.

To do this, I use the code snippet below that searches recursively. Now the problem is how I escape from recursion when it meets both of my requirements.

 boolean bFileFound = false;
File  fileFound     = null;

private void findFile( File aFile, String sDir ){

    String  filePath = aFile.getAbsolutePath();

    if( aFile.isFile() && filePath.contains( sDir ) ){

              if( aFile.getName().contains( "test2.adv")){
                  Log.d(TAG, "[FILE] " + aFile.getName() );
                  fileFound = aFile;
                  bFileFound = true;
              }

             // return true;
    }else if( aFile.isDirectory() ){

        String sDirName = aFile.getName();
        Log.d(TAG, "[DIR] " + sDirName );

        if( sDirName.contains( sDir ) ){

            Log.d( TAG, "Found the directory..& Absolute Path = " + aFile.getAbsolutePath());
            sDir = sDirName;
        }

        File[] listFiles = aFile.listFiles();

        if( listFiles != null ){

          for( int i = 0; i < listFiles.length; i++ ){

              if(bFileFound)
                    return;

            findFile( listFiles[ i ], sDir );
          }
        }else{

          Log.d( TAG,  " [ACCESS DENIED]" );
        }
    }

   // return null;
}

Thanks, DK

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2 answers
/**
 * Search file a file in a directory. Please comment more here, your method is not that standard.
 * @param file the file / folder where to look our file for.
 * @param sDir a directory that must be in the path of the file to find
 * @param toFind the name of file we are looking for. 
 * @return the file we were looking for. Null if no such file could be found.
 */
private File findFile( File aFile, String sDir, String toFind ){
    if( aFile.isFile() && 
            aFile.getAbsolutePath().contains( sDir ) && 
            aFile.getName().contains( toFind ) ) {
                        return aFile;
        } else if( aFile.isDirectory() ) {
        for( File child : aFile.listFiles() ){
            File found = findFile( child, sDir, toFind );
                    if( found != null ) { 
                        return found;
                    }//if
        }//for
    }//else
   return null;
}//met

Now pass "test2.adv" as the third parameter when you call findFile. This is more interesting than hardcoding.

Also note that several files may correspond to your search, this function does not cope with this, it will return the first one found.

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, FileFilter . ".json", .

, FileFilter,

/**
 * A {@link FileFilter} implementation that checks recursively files of a
 * specified fileName or extension string
 */
public class FileExtensionFinder implements FileFilter {
    private final String fileName;
    private final List<File> foundFiles;

    /**
     * Constructor for FileExtensionFinder
     * @param fileName string of the filename or extension being searched for
     */
    public FileExtensionFinder(String fileName) {
        this.fileName = fileName;
        this.foundFiles = new ArrayList<>();
    }

    @Override
    public boolean accept(File pathname) {
        // accept anything that is a folder or matches the fileName string
        return pathname.isDirectory() || pathname.getName().toLowerCase().endsWith(fileName);
    }

    /**
     * Searches recursively for all files with the provided filename/extension string
     * @param filesArray an array of files (including folders) to iterate over
     */
    public List<File> findFiles(File... filesArray) {
        for (File file : filesArray) {
            if (file.isDirectory()) {
                findFiles(file.listFiles(this));
            } else if (file.getName().toLowerCase().endsWith(fileName)) {
                foundFiles.add(file);
            }
        }
        return foundFiles;
    }
}

, :

File fileLocation = // get your file here ...
List<File> foundFiles = new FileExtensionFinder(".json").findFiles(fileLocation);
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