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Android Android Data Persistence File Storage Writing to Internal Storage

Posted by Shubham Agrawal
Shubham Agrawal
7,169 Points

Using fileToWrite.exists() method of file class doesn't work. Why?

I'm applying the check right before the method copyResult(in, out) is being called. What am I missing?

FileUtilities.java 
import java.io.InputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class FileUtilities {

  public static boolean copyResult;

  public static void saveAssetImage(Context context, String assetName) {
    File fileToWrite = new File(context.getFilesDir(), assetName);
    AssetManager assetManager = context.getAssets();

    try {
      InputStream in = assetManager.open(assetName);
      FileOutputStream out = new FileOutputStream(fileToWrite);
      if(fileToWrite.exists())
        copyResult = copyFile(in, out);
    } catch(FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  private static boolean copyFile(InputStream in, FileOutputStream out) {
    // Copy magic intentionally omitted
    return true;
  }
}

1 Answer

Chase Marchione
Chase Marchione
155,055 Points
Chase Marchione
Chase Marchione
155,055 Points

You're so close! You only want the file to be written if it does not already exist. Your 16th line is what needs adjusting... you're almost there.

Example answer:

import java.io.InputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class FileUtilities {

  public static boolean copyResult;

  public static void saveAssetImage(Context context, String assetName) {
    File fileToWrite = new File(context.getFilesDir(), assetName);
    AssetManager assetManager = context.getAssets();

    try {
      InputStream in = assetManager.open(assetName);
      FileOutputStream out = new FileOutputStream(fileToWrite);
      if(fileToWrite.exists() == false)
        copyResult = copyFile(in, out);
    } catch(FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  private static boolean copyFile(InputStream in, FileOutputStream out) {
    // Copy magic intentionally omitted
    return true;
  }
}
Shubham Agrawal
Shubham Agrawal
7,169 Points

Thanks! :)