Java ByteBuffer to Long toLong(ByteBuffer buffer)

Description

Convert buffer to an long.

License

Open Source License

Parameter

Parameter	Description
buffer	A buffer containing an integer in flush mode. The position is not changed.

Return

an int

Declaration

public static long toLong(ByteBuffer buffer) 

Method Source Code

//package com.java2s;
//  are made available under the terms of the Eclipse Public License v1.0

import java.nio.ByteBuffer;

import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;

public class Main {
    static final byte SPACE = 0x20;
    static final byte MINUS = '-';

    /**/*from   ww  w .  j  a v  a2 s . co  m*/
     * Convert buffer to an long. Parses up to the first non-numeric character. If no number is found an IllegalArgumentException is thrown
     *
     * @param buffer
     *            A buffer containing an integer in flush mode. The position is not changed.
     * @return an int
     */
    public static long toLong(ByteBuffer buffer) {
        long val = 0;
        boolean started = false;
        boolean minus = false;

        for (int i = buffer.position(); i < buffer.limit(); i++) {
            byte b = buffer.get(i);
            if (b <= SPACE) {
                if (started)
                    break;
            } else if (b >= '0' && b <= '9') {
                val = val * 10L + (b - '0');
                started = true;
            } else if (b == MINUS && !started) {
                minus = true;
            } else
                break;
        }

        if (started)
            return minus ? (-val) : val;
        throw new NumberFormatException(toString(buffer));
    }

    /** Convert the buffer to an ISO-8859-1 String
     * @param buffer The buffer to convert in flush mode. The buffer is unchanged
     * @return The buffer as a string.
     */
    public static String toString(ByteBuffer buffer) {
        return toString(buffer, StandardCharsets.ISO_8859_1);
    }

    /** Convert the buffer to an ISO-8859-1 String
     * @param buffer  The buffer to convert in flush mode. The buffer is unchanged
     * @param charset The {@link Charset} to use to convert the bytes
     * @return The buffer as a string.
     */
    public static String toString(ByteBuffer buffer, Charset charset) {
        if (buffer == null)
            return null;
        byte[] array = buffer.hasArray() ? buffer.array() : null;
        if (array == null) {
            byte[] to = new byte[buffer.remaining()];
            buffer.slice().get(to);
            return new String(to, 0, to.length, charset);
        }
        return new String(array, buffer.arrayOffset() + buffer.position(), buffer.remaining(), charset);
    }

    /** Convert a partial buffer to a String.
     * 
     * @param buffer the buffer to convert 
     * @param position The position in the buffer to start the string from
     * @param length The length of the buffer
     * @param charset The {@link Charset} to use to convert the bytes
     * @return  The buffer as a string.
     */
    public static String toString(ByteBuffer buffer, int position, int length, Charset charset) {
        if (buffer == null)
            return null;
        byte[] array = buffer.hasArray() ? buffer.array() : null;
        if (array == null) {
            ByteBuffer ro = buffer.asReadOnlyBuffer();
            ro.position(position);
            ro.limit(position + length);
            byte[] to = new byte[length];
            ro.get(to);
            return new String(to, 0, to.length, charset);
        }
        return new String(array, buffer.arrayOffset() + position, length, charset);
    }
}

Related

1. readUInt64(ByteBuffer byteBuffer)
2. readUInt8(ByteBuffer bb)
3. readVarLong(ByteBuffer buff)
4. readVarlong(ByteBuffer buffer)
5. toLong(ByteBuffer buffer)
6. toLong(ByteBuffer bytes)
7. toLong(ByteBuffer value)