Realization of File Reading and Writing by android Development

In this paper, we share the specific code of android to read and write files for your reference. The specific contents are as follows

Read

/**
*  File reading 
* @param is  Input stream of file 
* @return  Returns an array of files 
*/
private byte[] read(InputStream is) {
  // Buffer inputStream
  BufferedInputStream bis = null;
  // Used to store data 
  ByteArrayOutputStream baos = null;
  try {
    // Every time you read 1024
    byte[] b = new byte[1024];
    // Initialization 
    bis = new BufferedInputStream(is);
    baos = new ByteArrayOutputStream();
    
    int length;
    while ((length = bis.read(b)) != -1) {
      //bis.read() The read data is added to the b Array 
      // Writes an array to the baos Medium 
      baos.write(b, 0, length);
    }
    return baos.toByteArray();

  } catch (IOException e) {
    e.printStackTrace();
  } finally {// Close flow 
    try {
      if (bis != null) {
        bis.close();
      }
      if (is != null) {
        is.close();
      }

      if (baos != null) baos.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  return null;
}

Write

/**
 *  Write data to a file 
 * @param buffer  Write data 
 * @param fos   File output stream 
 */
private void write(byte[] buffer, FileOutputStream fos) {
  // Buffer OutputStream
  BufferedOutputStream bos = null;
  try {
    // Initialization 
    bos = new BufferedOutputStream(fos);
    // Write 
    bos.write(buffer);
    // Refresh buffer 
    bos.flush();
  } catch (IOException e) {
    e.printStackTrace();
  } finally {// Close flow 
    try {
      if (bos != null) {
        bos.close();
      }
      if (fos != null) {
        fos.close();
      }
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

Use

// Get the file input stream 
InputStream mRaw = getResources().openRawResource(R.raw.core);

// Read a file 
byte[] bytes = read(mRaw);

// Create a file (getFilesDir() The path is in data/data/< Package name >/files, Need root To see the path )
File file = new File(getFilesDir(), "hui.mp3");
boolean newFile = file.createNewFile();

// Write 
if (bytes != null) {
 FileOutputStream fos = openFileOutput("hui.mp3", Context.MODE_PRIVATE);
 write(bytes, fos);
}

This step is a time-consuming operation and is best performed on an io thread