Android: accessing a file from internal storage using RandomAccessFile

Question

I am creating an application that should read data from a file. At first I read it from the resource folder using BufferedReaderand InputStreamReader, but I had problems with memory (see Android: reading files is the OutOfMemory problem ), One of the suggestions was to copy the data from the assets folder to the internal storage ( , and not an SD card ) and then access it through RandomAccessFile. So I was looking for how to copy files from assets to internal storage, and I found 2 sources:

https://groups.google.com/forum/?fromgroups=#!topic/android-developers/RpXiMYV48Ww

http://developergoodies.blogspot.com/2012/11/copy-android-asset-to-internal-storage.html

I decided to use the code from the second and changed it for my file. So it looks like this:

public void copyFile() {
    //Open your file in assets
    Context context = getApplicationContext();
    String destinationFile = context.getFilesDir().getPath() + File.separator + "text.txt";

    if (!new File(destinationFile).exists()) {
        try {
            copyFromAssetsToStorage(context, "text.txt", destinationFile);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }   
}

private void copyStream(InputStream input, OutputStream output) throws IOException {
    byte[] buffer = new byte[1024];
    int length = Input.read(buffer);
    while (length > 0) {
        output.write(buffer, 0, length);
        length = input.read(buffer);
    }
}

private void copyFromAssetsToStorage(Context context, String sourceFile, String destinationFile) throws IOException {
    InputStream inputStream = context.getAssets().open(sourceFile);
    OutputStream outputStream = new FileOutputStream(destinationFile);
    copyStream(inputStream , outputStream );
    outputStream.flush();
    outputStream.close();
    inputStream.close();
}

I assume this copies the file to the application data directory. I could not verify it because I would like to access the file using RandomAccessFile. However, I never did either of these two (copying a file from assets and RandomAccessFile), so I'm stuck. Work on this application has come to a standstill because it is the only thing that prevents me from completing it.

Can someone provide me with corrections, suggestions and the correct options for accessing data using RandomAccessFile? (The data is a list of lines 4-15 characters long per line.)

EDIT *

private File createCacheFile(Context context, String filename){
File cacheFile = new File(context.getCacheDir(), filename);

    if (cacheFile.exists()) {
        return cacheFile ;
    }

    InputStream inputStream = null;
    FileOutputStream fileOutputStream = null;

    try {

        inputStream = context.getAssets().open(filename);
        fileOutputStream = new FileOutputStream(cacheFile);

        int bufferSize = 1024;
        byte[] buffer = new byte[bufferSize];
        int length = -1;
        while ( (length = inputStream.read(buffer)) > 0) {
            fileOutputStream.write(buffer,0,length);
        }

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    finally {
        try {
            fileOutputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    return cacheFile;
}

Answer 1

1-

,

private File createCacheFile(Context context, String filename){
  File cacheFile = new File(context.getCacheDir(), filename);

  if (cacheFile.exists()) {
      return cacheFile ;
  }


  InputStream inputStream = context.getAssets().open(filename);
  FileOutputStream fileOutputStream = new FileOutputStream(cacheFile);

  int bufferSize = 1024;
  byte[] buffer = new byte[bufferSize];
  int length = -1;
  while ( (length = inputStream.read(buffer)) > 0) {
     fileOutputStream.write(buffer,0,length);
  }

  fileOutputStream.close();
  inputStream.close();

  return cacheFile;
}

2- , RandomAccessFile

File cacheFile = createCacheFile(context, "text.txt");
RandomAccessFile randomAccessFile = new RandomAccessFile(cacheFile, "r");

// Process the file

randomAccessFile.close();    

, Java, . , copyFromAssetsToStorage destinationFile

Edit:

try/catch close(), , - , , null

finally {
    try {
       if(fileOutputStream!=null){
          fileOutputStream.close();            
       }
    } catch (IOException e) {
        e.printStackTrace();
    }

    try {
      if(inputStream!=null){
       inputStream.close();      
      }      
    } catch (IOException e) {
        e.printStackTrace();
    }
}