Main.java Source code

Introduction

Here is the source code for Main.java

Source

import static java.nio.file.StandardOpenOption.CREATE;
import static java.nio.file.StandardOpenOption.READ;
import static java.nio.file.StandardOpenOption.TRUNCATE_EXISTING;
import static java.nio.file.StandardOpenOption.WRITE;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.SeekableByteChannel;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class Main {
    public static void main(String[] args) {
        Path src = Paths.get("test.txt");
        String encoding = System.getProperty("file.encoding");
        Charset cs = Charset.forName(encoding);
        try (SeekableByteChannel seekableChannel = Files.newByteChannel(src, READ, WRITE, CREATE,
                TRUNCATE_EXISTING)) {
            printDetails(seekableChannel, "Before writing data");
            writeData(seekableChannel, cs);
            printDetails(seekableChannel, "After writing data");

            seekableChannel.position(0);
            printDetails(seekableChannel, "After resetting position to 0");
            readData(seekableChannel, cs);
            printDetails(seekableChannel, "After reading data");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void writeData(SeekableByteChannel seekableChannel, Charset cs) throws IOException {
        String separator = System.getProperty("line.separator");
        StringBuilder sb = new StringBuilder();
        sb.append("test");
        sb.append(separator);
        sb.append("test2");
        sb.append(separator);

        CharBuffer charBuffer = CharBuffer.wrap(sb);
        ByteBuffer byteBuffer = cs.encode(charBuffer);
        seekableChannel.write(byteBuffer);
    }

    public static void readData(SeekableByteChannel seekableChannel, Charset cs) throws IOException {
        ByteBuffer byteBuffer = ByteBuffer.allocate(128);
        String encoding = System.getProperty("file.encoding");
        while (seekableChannel.read(byteBuffer) > 0) {
            byteBuffer.rewind();
            CharBuffer charBuffer = cs.decode(byteBuffer);
            System.out.print(charBuffer);
            byteBuffer.flip();
        }
    }

    public static void printDetails(SeekableByteChannel seekableChannel, String msg) {
        try {
            System.out.println(
                    msg + ": Size   = " + seekableChannel.size() + ", Position = " + seekableChannel.position());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}