Best way to write String to file using java nio

Question

I need to write(append) huge string to flat file using java nio. The encoding is ISO-8859-1.

Currently we are writing as shown below. Is there any better way to do the same ?

public void writeToFile(Long limit) throws IOException{      String fileName = "/xyz/test.txt";      File file = new File(fileName);              FileOutputStream fileOutputStream = new FileOutputStream(file, true);        FileChannel fileChannel = fileOutputStream.getChannel();      ByteBuffer byteBuffer = null;      String messageToWrite = null;      for(int i=1; i<limit; i++){          //messageToWrite = get String Data From database          byteBuffer = ByteBuffer.wrap(messageToWrite.getBytes(Charset.forName("ISO-8859-1")));          fileChannel.write(byteBuffer);               }      fileChannel.close(); } 

EDIT: Tried both options. Following are the results.

@Test public void testWritingStringToFile() {     DiagnosticLogControlManagerImpl diagnosticLogControlManagerImpl = new DiagnosticLogControlManagerImpl();     try {         File file = diagnosticLogControlManagerImpl.createFile();         long startTime = System.currentTimeMillis();         writeToFileNIOWay(file);         //writeToFileIOWay(file);         long endTime = System.currentTimeMillis();         System.out.println("Total Time is  " + (endTime - startTime));     } catch (IOException e) {         // TODO Auto-generated catch block         e.printStackTrace();     } }  /**  *  * @param limit  *            Long  * @throws IOException  *             IOException  */ public void writeToFileNIOWay(File file) throws IOException {     FileOutputStream fileOutputStream = new FileOutputStream(file, true);     FileChannel fileChannel = fileOutputStream.getChannel();     ByteBuffer byteBuffer = null;     String messageToWrite = null;     for (int i = 1; i < 1000000; i++) {         messageToWrite = "This is a test üüüüüüööööö";         byteBuffer = ByteBuffer.wrap(messageToWrite.getBytes(Charset             .forName("ISO-8859-1")));         fileChannel.write(byteBuffer);     } }  /**  *  * @param limit  *            Long  * @throws IOException  *             IOException  */ public void writeToFileIOWay(File file) throws IOException {     FileOutputStream fileOutputStream = new FileOutputStream(file, true);     BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(         fileOutputStream, 128 * 100);     String messageToWrite = null;     for (int i = 1; i < 1000000; i++) {         messageToWrite = "This is a test üüüüüüööööö";         bufferedOutputStream.write(messageToWrite.getBytes(Charset             .forName("ISO-8859-1")));     }     bufferedOutputStream.flush();     fileOutputStream.close(); }  private File createFile() throws IOException {     File file = new File(FILE_PATH + "test_sixth_one.txt");     file.createNewFile();     return file; } 

Using ByteBuffer and Channel: took 4402 ms

Using buffered Writer : Took 563 ms

Answer 1

UPDATED:

Since Java11 there is a specific method to write strings using java.nio.file.Files:

Files.writeString(Paths.get(file.toURI()), "My string to save"); 

We can also customize the writing with:

Files.writeString(Paths.get(file.toURI()),                    "My string to save",                     StandardCharsets.UTF_8,                    StandardOpenOption.CREATE,                    StandardOpenOption.TRUNCATE_EXISTING); 

ORIGINAL ANSWER:

There is a one-line solution, using Java nio:

java.nio.file.Files.write(Paths.get(file.toURI()),                            "My string to save".getBytes(StandardCharsets.UTF_8),                           StandardOpenOption.CREATE,                           StandardOpenOption.TRUNCATE_EXISTING); 

I have not benchmarked this solution with the others, but using the built-in implementation for open-write-close file should be fast and the code is quite small.