Java Tutorial/File/IntBuffer

Convert ByteBuffer to an IntBuffer

   <source lang="java">

import java.nio.ByteBuffer; import java.nio.IntBuffer; public class MainClass {

 public static void main(String[] args) {
   ByteBuffer bb = ByteBuffer.wrap(new byte[] { 0, 0, 0, 0, 0, 0, 0, "a" });
   bb.rewind();
   IntBuffer ib = ((ByteBuffer) bb.rewind()).asIntBuffer();
   System.out.println("Int Buffer");
   while (ib.hasRemaining())
     System.out.println(ib.position() + " -> " + ib.get());
 }

} /*

*/</source>
   
  
 
  

Int Buffer
0 -> 0
1 -> 97

Manipulating ints in a ByteBuffer with an IntBuffer

   <source lang="java">

import java.nio.ByteBuffer; import java.nio.IntBuffer; public class MainClass {

 private static final int BSIZE = 1024;
 public static void main(String[] args) {
   ByteBuffer bb = ByteBuffer.allocate(BSIZE);
   IntBuffer ib = bb.asIntBuffer();

   ib.put(new int[] { 1, 2, 7, 9, 3, 8, 6 });

   System.out.println(ib.get(3));
   ib.put(3, 1811);
   ib.rewind();
   while (ib.hasRemaining()) {
     int i = ib.get();
     if (i == 0)
       break; // Else we"ll get the entire buffer
     System.out.println(i);
   }
 }

} /*

• /</source>

9
1
2
7
1811
3
8
6

Map FileChannel to an IntBuffer and read from the IntBuffer

   <source lang="java">

import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.nio.IntBuffer; import java.nio.channels.FileChannel; public class MainClass {

 public static void main(String[] args) throws IOException {
   FileChannel fc = new FileInputStream(new File("temp.tmp")).getChannel();
   IntBuffer ib = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size()).asIntBuffer();
   while (ib.hasRemaining())
     ib.get();
   fc.close();
 }

}</source>

Put integers to a mapped IntBuffer

   <source lang="java">

import java.io.File; import java.io.IOException; import java.io.RandomAccessFile; import java.nio.IntBuffer; import java.nio.channels.FileChannel; public class MainClass {

 public static void main(String[] args) throws IOException {
   FileChannel fc = new RandomAccessFile(new File("temp.tmp"), "rw").getChannel();
   IntBuffer ib = fc.map(FileChannel.MapMode.READ_WRITE, 0, fc.size()).asIntBuffer();
   ib.put(0);
   for (int i = 1; i < 10; i++)
     ib.put(ib.get(i - 1));
   fc.close();
 }

}</source>

Use while loop to read an IntBuffer

   <source lang="java">

import java.nio.ByteBuffer; import java.nio.IntBuffer; public class MainClass {

 public static void main(String[] args) {
   ByteBuffer bb = ByteBuffer.wrap(new byte[] { 0, 0, 0, 0, 0, 0, 0, "a" });
   bb.rewind();
   IntBuffer ib = ((ByteBuffer) bb.rewind()).asIntBuffer();
   System.out.println("Int Buffer");
   while (ib.hasRemaining())
     System.out.println(ib.position() + " -> " + ib.get());
 }

} /*

*/</source>
   
  
 
  

Int Buffer
0 -> 0
1 -> 97