Example of SeekableByteChannel in Java | java.nio.channels API
November 29, 2013
position() : returns the position of SeekableByteChannel in the file or any other entity.
position(long new) : It sets new position of SeekableByteChannel and start reading or writing from that position.
read(ByteBuffer dst) : reads a file into ByteBuffer.
size() : It returns the size of file which is SeekableByteChannel is connected..
truncate(long size) : It truncates the file with which SeekableByteChannel is connected.
write(ByteBuffer src) : Writes the byte array to the given Path.
How to instantiate SeekableByteChannel | Files.newByteChannel()
Files.newByteChannel returns the object of SeekableByteChannel . SeekableByteChannel opens a file to read or write and returns SeekableByteChannel. The syntax is given below.public static SeekableByteChannel newByteChannel(Path path, OpenOption... opts)
Read File Using java.nio.channels.SeekableByteChannel
SeekableByteChannelExample.java
package com.concretepage.io.file;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
public class SeekableByteChannelExample {
public static void main(String[] args) throws IOException {
Path path = Paths.get("D:/cp","file1.txt");
SeekableByteChannel sbc = Files.newByteChannel(path, StandardOpenOption.READ);
ByteBuffer bf = ByteBuffer.allocate(1024);
int i = 0;
while((i=sbc.read(bf))>0){
bf.flip();
System.out.println(i);
bf.clear();
}
}
}
Write File Using java.nio.channels. SeekableByteChannel
SeekableByteChannelExample.java
package com.concretepage.io.file;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
public class SeekableByteChannelExample {
public static void main(String[] args) throws IOException {
Path path = Paths.get("D:/cp","file.txt");
SeekableByteChannel sbc = Files.newByteChannel(path, StandardOpenOption.APPEND);
String s= "Hellow World!";
ByteBuffer bfSrc = ByteBuffer.wrap(s.getBytes());
sbc.write(bfSrc);
sbc.close();
}
