Java Tutorial/File/BufferedOutputStream

Append string to a text file

   <source lang="java">

import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.PrintStream; public class Main {

 public static void main(String[] argv) {
   append(new File("c:\\a.txt"), "value");
 }
 public static void append(File aFile, String content) {
   try {
     PrintStream p = new PrintStream(new BufferedOutputStream(new FileOutputStream(aFile, true)));
     p.println(content);
     p.close();
   } catch (Exception e) {
     e.printStackTrace();
     System.err.println(aFile);
   }
 }

}</source>

BufferedOutputStream

You should always wrap your OutputStream with a BufferedOutputStream for better performance. The BufferedOutputStream class has two constructors that accept an OutputStream.

   <source lang="java">

public BufferedOutputStream (OutputStream out) public BufferedOutputStream (OutputStream out, int bufferSize)</source>

Create DataInputStream out of BufferedInputStream

   <source lang="java">

import java.io.BufferedInputStream; import java.io.DataInputStream; import java.io.EOFException; import java.io.FileInputStream; import java.io.IOException; public class PrimeReader {

 public static void main(String[] arguments) {
   try {
     FileInputStream file = new FileInputStream("400primes.dat");
     BufferedInputStream buff = new BufferedInputStream(file);
     DataInputStream data = new DataInputStream(buff);
     try {
       while (true) {
         int in = data.readInt();
         System.out.print(in + " ");
       }
     } catch (EOFException eof) {
       buff.close();
     }
   } catch (IOException e) {
     System.out.println("Error - " + e.toString());
   }
 }

}</source>

Create DataOutputStream out of BufferedOutputStream

   <source lang="java">

import java.io.BufferedOutputStream; import java.io.DataOutputStream; import java.io.FileOutputStream; import java.io.IOException; public class PrimeWriter {

 public static void main(String[] arguments) {
   int[] primes = new int[400];
   int numPrimes = 0;
   int candidate = 2;
   while (numPrimes < 400) {
     primes[numPrimes] = candidate;
     numPrimes++;
     candidate++;
   }
   try {
     FileOutputStream file = new FileOutputStream("p.dat");
     BufferedOutputStream buff = new BufferedOutputStream(file);
     DataOutputStream data = new DataOutputStream(buff);
     for (int i = 0; i < 400; i++)
       data.writeInt(primes[i]);
     data.close();
   } catch (IOException e) {
     System.out.println("Error - " + e.toString());
   }
 }

}</source>

Write byte array to file using BufferedOutputStream

   <source lang="java">

import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; public class Main {

 public static void main(String[] args) throws Exception {
   FileOutputStream fos = new FileOutputStream(new File("C:/Demo"));
   BufferedOutputStream bos = new BufferedOutputStream(fos);
   bos.write("this is a test".getBytes());
   bos.flush();
   bos.close();
 }

}</source>

Write byte to file using BufferedOutputStream

   <source lang="java">

import java.io.BufferedOutputStream; import java.io.FileOutputStream; public class Main {

 public static void main(String[] args) throws Exception {
   FileOutputStream fos = new FileOutputStream("C:/Demo.txt");
   BufferedOutputStream bos = new BufferedOutputStream(fos);
   byte b = 66;
   // write a character represented by ascii 66 i.e. "B"
   bos.write(b);
   bos.flush();
   bos.close();
 }

}</source>

Write to file using BufferedOutputStream

   <source lang="java">

import java.io.BufferedOutputStream; import java.io.FileOutputStream; public class Main {

 public static void main(String[] args) throws Exception {
   BufferedOutputStream bufferedOutput = new BufferedOutputStream(new FileOutputStream(
       "yourFile.txt"));
   bufferedOutput.write("Line one".getBytes());
   bufferedOutput.write("\n".getBytes());
   bufferedOutput.write(65);
   bufferedOutput.close();
 }

}</source>