Java converts bytes to 16 binary strings

Many times we need to convert a byte array into a 16 binary string to save, such as when I am I/O byte stream operation, especially in a lot of encrypted scenes application is more extensive.

In Java, Byte uses a binary representation of 8 bits, and we know that each character of the 16 binary needs to be represented by a 4-bit bits, so we can convert each byte to two corresponding 16 characters, that is, the high 4-bit and low 4 bits of byte are converted to the corresponding 16-character H and L, respectively. and combine to get the result of a byte conversion to a 16 binary string new string (H) + new String (L). That is, byte represents only 2 bits in hexadecimal notation.

As can be seen from the above we only need to remove the high four-bit and low four-bit binary values, and then the corresponding conversion.

The specific options are as follows:

    /**     * 0x0F  hexadecimal f  equals value   decimal  15, Binary representation of  0000 1111  binary  1 &  any number is the original number   binary  0 &  any number is 0      *      *  @param  b      *  @return      */    public static  String bytetohexstring (byte b)  {        final  string hex =  "0123456789abcdef";         stringbuilder  sb = new stringbuilder ();        /**          *  why with 0xof arithmetic   because the binary of 0xof is 0000 1111, while the 1& operation obtains the original number, 0 The & Operation concludes 0         */         // 1. Remove the high four-bit value of byte B and append         //  the high four-bit to the right four-bit, and the  0x0f operation results in a high four-bit value          sb.append (Hex.charat ((b >> 4)  & 0x0f));         // 2. Remove the low four-bit value and append         //  direct to The  0x0f operation results in a low four-bit numeric         sb.append (Hex.charat (b &  0x0f));         return sb.tostring ();     }

Summarized as follows:

(1) A byte corresponds to a two-bit hexadecimal bit instead of a eight-bit (32-bit bits);

(2) After the conversion to hexadecimal, less than two, the high level to fill 0.

This article is from the "Wang Wei" blog, make sure to keep this source http://jaydenwang.blog.51cto.com/6033165/1746161

Java converts bytes to 16 binary strings