Java String和十六进制字符串互相转换 示例

public class HelloWorld {
    public static void main(String []args) {
        
       String str = "Hello World!";
       System.out.println(str);
        
       String hexStr = str2HexStr(str);
       System.out.println(hexStr);
       
       String str2 = hexStr2Str(hexStr);
       System.out.println(str2);
        
    }
    
    /**
      * 字符串转换成为16进制(无需Unicode编码)
      * @param str
      * @return
     */
    public static String str2HexStr(String str) {
        char[] chars = "0123456789ABCDEF".toCharArray();
        StringBuilder sb = new StringBuilder("");
        byte[] bs = str.getBytes();
        int bit;
        for (int i = 0; i < bs.length; i++) {
            bit = (bs[i] & 0x0f0) >> 4;
            // 注意此处，有的地方不使用空格分隔
            sb.append(" " + chars[bit]);
            bit = bs[i] & 0x0f;
            sb.append(chars[bit]);
        }
        return sb.toString().trim();
    }
    
     /**
      * 16进制直接转换成为字符串(无需Unicode解码)
      * @param hexStr
      * @return
     */
    public static String hexStr2Str(String hexStr) {
        String str = "0123456789ABCDEF";
        // 注意此处，有的地方不使用空格分隔
        hexStr = hexStr.replace(" ", "");
        char[] hexs = hexStr.toCharArray();
        byte[] bytes = new byte[hexStr.length() / 2];
        int n;
        for (int i = 0; i < bytes.length; i++) {
            n = str.indexOf(hexs[2 * i]) * 16;
            n += str.indexOf(hexs[2 * i + 1]);
            bytes[i] = (byte) (n & 0xff);
        }
        return new String(bytes);
    }


}