ByteUtil.java

package cn.wisenergy.common.utils;

import java.io.*;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;

/**
 * 字节转换工具类
 */
public class ByteUtil {

    /**
     * 字节数组转字符数组
     *
     * @param bytes
     * @return
     */
    public static char[] byteArrTocharArr(byte[] bytes) {
        Charset cs = Charset.forName("UTF-8");
        ByteBuffer bb = ByteBuffer.allocate(bytes.length);
        bb.put(bytes);
        bb.flip();
        CharBuffer cb = cs.decode(bb);
        return cb.array();
    }

    /**
     * char数组转Byte数组
     *
     * @param chars
     * @return
     */
    public static byte[] charArrToByteArr(char[] chars) {
        Charset cs = Charset.forName("UTF-8");
        CharBuffer cb = CharBuffer.allocate(chars.length);
        cb.put(chars);
        cb.flip();
        ByteBuffer bb = cs.encode(cb);
        return bb.array();
    }

    public static byte[] hexStringToByte(String hex) {
        int len = (hex.length() / 2);
        byte[] result = new byte[len];
        char[] achar = hex.toCharArray();
        for (int i = 0; i < len; i++) {
            int pos = i * 2;
            result[i] = (byte) (toByte(achar[pos]) << 4 | toByte(achar[pos + 1]));
        }
        return result;
    }

    private static byte toByte(char c) {
        byte b = (byte) "0123456789ABCDEF".indexOf(c);
        return b;
    }

    /**
     * 把字节数组转换成16进制字符串
     *
     * @param bArray
     * @return
     */
    public static final String bytesToHexString(byte[] bArray) {
        StringBuffer sb = new StringBuffer(bArray.length);
        String sTemp;
        for (int i = 0; i < bArray.length; i++) {
            sTemp = Integer.toHexString(0xFF & bArray[i]);
            if (sTemp.length() < 2)
                sb.append(0);
            sb.append(sTemp.toUpperCase());
        }
        return sb.toString();
    }

    /**
     * 把字节数组转换为对象
     *
     * @param bytes
     * @return
     * @throws IOException
     * @throws ClassNotFoundException
     */
    public static final Object bytesToObject(byte[] bytes) throws IOException, ClassNotFoundException {
        ByteArrayInputStream in = new ByteArrayInputStream(bytes);
        ObjectInputStream oi = new ObjectInputStream(in);
        Object o = oi.readObject();
        oi.close();
        return o;
    }

    /**
     * 把可序列化对象转换成字节数组
     *
     * @param s
     * @return
     * @throws IOException
     */
    public static final byte[] objectToBytes(Object s) throws IOException {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ObjectOutputStream ot = new ObjectOutputStream(out);
        ot.writeObject(s);
        ot.flush();
        ot.close();
        return out.toByteArray();
    }

    public static final String objectToHexString(Serializable s) throws IOException {
        return bytesToHexString(objectToBytes(s));
    }

    public static final Object hexStringToObject(String hex) throws IOException, ClassNotFoundException {
        return bytesToObject(hexStringToByte(hex));
    }

    /**
     * @函数功能: BCD码转为10进制串(阿拉伯数据)
     * @输入参数: BCD码
     * @输出结果: 10进制串
     */
    public static String bcd2Str(byte[] bytes) {
        StringBuffer temp = new StringBuffer(bytes.length * 2);

        for (int i = 0; i < bytes.length; i++) {
            temp.append((byte) ((bytes[i] & 0xf0) >>> 4));
            temp.append((byte) (bytes[i] & 0x0f));
        }
        return temp.toString().substring(0, 1).equalsIgnoreCase("0") ? temp.toString().substring(1) : temp.toString();
    }

    /**
     * @函数功能: 10进制串转为BCD码
     * @输入参数: 10进制串
     * @输出结果: BCD码
     */
    public static byte[] str2Bcd(String asc) {
        int len = asc.length();
        int mod = len % 2;

        if (mod != 0) {
            asc = "0" + asc;
            len = asc.length();
        }

        byte abt[] = new byte[len];
        if (len >= 2) {
            len = len / 2;
        }

        byte bbt[] = new byte[len];
        abt = asc.getBytes();
        int j, k;

        for (int p = 0; p < asc.length() / 2; p++) {
            if ((abt[2 * p] >= '0') && (abt[2 * p] <= '9')) {
                j = abt[2 * p] - '0';
            } else if ((abt[2 * p] >= 'a') && (abt[2 * p] <= 'z')) {
                j = abt[2 * p] - 'a' + 0x0a;
            } else {
                j = abt[2 * p] - 'A' + 0x0a;
            }

            if ((abt[2 * p + 1] >= '0') && (abt[2 * p + 1] <= '9')) {
                k = abt[2 * p + 1] - '0';
            } else if ((abt[2 * p + 1] >= 'a') && (abt[2 * p + 1] <= 'z')) {
                k = abt[2 * p + 1] - 'a' + 0x0a;
            } else {
                k = abt[2 * p + 1] - 'A' + 0x0a;
            }

            int a = (j << 4) + k;
            byte b = (byte) a;
            bbt[p] = b;
        }
        return bbt;
    }

    /**
     * 低位到高位排列的字节数组
     *
     * @param byte2Arr
     * @return
     */
    public static int bytesTo16Int(byte[] byte2Arr) {
        return (byte2Arr[0] & 0xFF) | (byte2Arr[1] << 8);
    }

    /**
     * 低位到高位排列的字节数组
     *
     * @param byte4Arr
     * @return
     */
    public static int bytesTo32Int(byte[] byte4Arr) {
        return (byte4Arr[0] & 0xFF) | ((byte4Arr[1] & 0xFF) << 8) | ((byte4Arr[2] & 0xFF) << 16) | ((byte4Arr[3] & 0xFF) << 24);
    }

    /**
     * 低位到高位
     *
     * @param b
     * @return
     */
    public static float bytesTo32Float(byte[] b) {
        int l;
        l = b[0];
        l &= 0xff;
        l |= ((long) b[1] << 8);
        l &= 0xffff;
        l |= ((long) b[2] << 16);
        l &= 0xffffff;
        l |= ((long) b[3] << 24);
        return Float.intBitsToFloat(l);
    }
}