This is a relative get String method for ByteBuffer because it doesn't have one (but should!). - Java java.nio

Java examples for java.nio:ByteBuffer String

  1. HOME
  2. Java
  3. java.nio
  4. ByteBuffer String

Description

This is a relative get String method for ByteBuffer because it doesn't have one (but should!).

Demo Code


//package com.java2s;
import java.io.*;
import java.nio.ByteBuffer;

public class Main {
    /**//  w  ww. j a  v a2s  .c o  m
     * This is a relative get {@link String} method for {@link ByteBuffer}
     * because it doesn't have one (but should!).
     *
     * @param buf The {@link ByteBuffer} to get bytes from.
     * @param length The number of bytes to be copied.
     * @param charsetName The name of a supported character set.
     * @return Returns a {@link String} comprising the bytes gotten.
     * @throws BufferUnderflowException if there are fewer than
     * <code>length</code> bytes remaining in the buffer.
     * @throws IllegalArgumentException if the offset is either negative or
     * beyond the buffer's limit, or <code>charsetName</code> specifies an
     * unsupported character set.
     */
    public static String getString(ByteBuffer buf, int length,
            String charsetName) {
        try {
            return new String(getBytes(buf, length), charsetName);
        } catch (UnsupportedEncodingException e) {
            throw new IllegalArgumentException(e);
        }
    }

    /**
     * This is an absolute get {@link String} method for {@link ByteBuffer}
     * because it doesn't have one (but should!).  The {@link ByteBuffer}'s
     * position is unchanged.
     *
     * @param buf The {@link ByteBuffer} to get bytes from.
     * @param offset The absolute offset within the {@link ByteBuffer} of the
     * first byte to be read; must be non-negative.
     * @param length The number of bytes to be copied.
     * @param charsetName The name of a supported character set.
     * @return Returns a {@link String} comprising the bytes gotten.
     * @throws BufferUnderflowException if there are fewer than
     * <code>length</code> bytes in the buffer starting at the given offset.
     * @throws IllegalArgumentException if the offset is either negative or
     * beyond the buffer's limit, or <code>charsetName</code> specifies an
     * unsupported character set.
     */
    public static String getString(ByteBuffer buf, int offset, int length,
            String charsetName) {
        try {
            return new String(getBytes(buf, offset, length), charsetName);
        } catch (UnsupportedEncodingException e) {
            throw new IllegalArgumentException(e);
        }
    }

    /**
     * This is a relative bulk get method for {@link ByteBuffer} that returns
     * the array of bytes gotten.  It is a convenience method so the array
     * doesn't have to be declared beforehand.
     *
     * @param buf The {@link ByteBuffer} to get bytes from.
     * @param length The number of bytes to be copied.
     * @return Returns an array of the bytes gotten.
     * @throws BufferUnderflowException if there are fewer than
     * <code>length</code> bytes remaining in the buffer.
     */
    public static byte[] getBytes(ByteBuffer buf, int length) {
        final byte[] dst = new byte[length];
        buf.get(dst, 0, length);
        return dst;
    }

    /**
     * This is an absolute bulk get method for {@link ByteBuffer} because it
     * doesn't have one (but should!).  Being absolute, the
     * {@link ByteBuffer}'s position doesn't change.
     *
     * @param buf The {@link ByteBuffer} to get bytes from.
     * @param offset The absolute offset within the {@link ByteBuffer} of the
     * first byte to be read; must be non-negative.
     * @param length The number of bytes to be copied.
     * @return Returns an array of the bytes gotten.
     * @throws BufferUnderflowException if there are fewer than
     * <code>length</code> bytes in the buffer starting at the given offset.
     * @throws IllegalArgumentException if the offset is either negative or
     * beyond the buffer's limit.
     */
    public static byte[] getBytes(ByteBuffer buf, int offset, int length) {
        final byte[] dst = new byte[length];
        getBytes(buf, offset, dst, 0, length);
        return dst;
    }

    /**
     * This is an absolute bulk get method for {@link ByteBuffer} because it
     * doesn't have one (but should!).  Being absolute, the
     * {@link ByteBuffer}'s position doesn't change.
     *
     * @param buf The {@link ByteBuffer} to get bytes from.
     * @param bufOffset The absolute offset within the {@link ByteBuffer} of
     * the first byte to be read; must be non-negative.
     * @param dst The array into which bytes are to be written.
     * @param dstOffset The offset within the destination array to start
     * writing bytes.
     * @param length The number of bytes to be copied.
     * @throws BufferUnderflowException if there are fewer than
     * <code>length</code> bytes in the buffer starting at the given offset.
     * @throws IllegalArgumentException if the offset is either negative or
     * beyond the buffer's limit.
     */
    public static void getBytes(ByteBuffer buf, int bufOffset, byte[] dst,
            int dstOffset, int length) {
        final int origPos = buf.position();
        buf.position(bufOffset);
        buf.get(dst, dstOffset, length);
        buf.position(origPos);
    }
}

Related Tutorials