JAVA byte[]数据类型之间的转换

古城微笑少年丶 2022-05-28 01:13 334阅读 0赞

# JAVA byte\[\]、十六进制字符串、整形(Long、int)数据类型之间的转换 #

在编程中我们经常遇到数据类型之间的转换,现在我们来总结一下,有更好的请大家共享指导：

*  **十六进制字符串数据 转 byte\[\]**
 *  **byte\[\] 转 十六进制字符串**
 *  **byte\[\] 转 int**
 *  **\*int 转 byte\[\]**
 *  **byte\[\] 转 Long**
 *  **Long 转 byte\[\]**

--------------------

### 十六进制字符串数据 转 byte\[\] ###

/**
         * 16进制字符串转byte
         * @param strIn
         * @return
         * @throws Exception
         */
        public static byte[] hexStr2ByteArr(String strIn) {
            try {
                if (strIn==null)return null;
                byte[] arrB = strIn.getBytes();
                int iLen = arrB.length;
                byte[] arrOut = new byte[iLen/2];
                for (int i = 0; i < iLen; i = i + 2) {
                    String strTmp = new String(arrB, i, 2);
                    arrOut[i / 2] = (byte) Integer.parseInt(strTmp, 16);
                }
                return arrOut;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }

### byte\[\] 转 十六进制字符串 ###

/** * 16进制的形式输出 * @param b * @return */
        public static String byte2HexStr(byte[] b){    
            String stmp="";    
            StringBuilder sb = new StringBuilder("");    
    
            try {
                for (int n=0;n<b.length;n++)    
                {    
                    stmp = Integer.toHexString(b[n] & 0xFF);    
                    sb.append((stmp.length()==1)? "0"+stmp : stmp);    
                    //sb.append(" "); 
                }
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }   
    
            return sb.toString().toUpperCase().trim();    
        }

### byte\[\] 转 int ###

/** * byte装成int * @param value * @return */
        public static int bytesToint(byte[] value) {
            int ret = 0;
            for (int i = 0; i < value.length; i++) {
                ret += (value[value.length - i - 1] & 0xFF) << (i * 8);
            }
            return ret;
        }

### int 转 byte\[\] ###

/** * 转成字节长度 * @param iSource 原数据 * @param iArrayLen 输出数据 * 只能转整形最多4个字节 * @return */
        public static byte[] toByteArray(int iSource, int iArrayLen) {
            byte[] bLocalArr = new byte[iArrayLen];
            for (int i = 0; (i < 4) && (i < iArrayLen); i++) {
                bLocalArr[i] = (byte) (iSource >> 8 * i & 0xFF);
            }
            byte temp;
            int len = bLocalArr.length;
            for (int i = 0; i < len / 2; i++) {
                temp = bLocalArr[i];
                bLocalArr[i] = bLocalArr[len - 1 - i];
                bLocalArr[len - 1 - i] = temp;
            }
            return bLocalArr;
        }

### byte\[\] 转 Long ###

/** * byte[] 转 Long * @return */
        public static long bytesToLong(byte[] value) {
            long ret = 0;
            for (int i = 0; i < value.length; i++) {
                ret += (long) (value[value.length - i - 1] & 0xFF) << (long) (i * 8);
            }
            return ret;
        }

### Long 转 byte\[\] ###

/** * Long 转 byte[] * @return */
        public static byte[] longTobytes(long val) {
            int length = 8;
            byte[] value = new byte[length];
            for (int i = 0; i < length; i++)
                value[length - i - 1] = (byte) (val >> i * 8);
    
            return value;
        }