Realization of File Reading and Writing by android Development
- 2021-12-05 07:13:52
- OfStack
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