Java中16進制與字符串之間的相互轉換

　*字符串轉化為Unicode編碼:

/**
 * 字符串轉換unicode
 */
public static String string2Unicode(String string) {
　　StringBuffer unicode = new StringBuffer();
　　for (int i = 0; i < string.length(); i++) {
　　　　// 取出每一個字符
    char c = string.charAt(i);
    // 轉換為unicode
    unicode.append("\\u" + Integer.toHexString(c));
　　}
　　return unicode.toString();
}  

*字符串轉為16進制

/**
 * 字符串轉化成為16進制字符串
 * @param s
 * @return
 */
public static String strTo16(String s) {
    String str = "";
    for (int i = 0; i < s.length(); i++) {
        int ch = (int) s.charAt(i);
        String s4 = Integer.toHexString(ch);
        str = str + s4;
    }
    return str;
}

*16進制轉為字符串

/**
 * 16進制轉換成為string類型字符串
 * @param s
 * @return
 */
public static String hexStringToString(String s) {
    if (s == null || s.equals("")) {
        return null;
    }
    s = s.replace(" ", "");
    byte[] baKeyword = new byte[s.length() / 2];
    for (int i = 0; i < baKeyword.length; i++) {
        try {
            baKeyword[i] = (byte) (0xff & Integer.parseInt(s.substring(i * 2, i * 2 + 2), 16));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    try {
        s = new String(baKeyword, "UTF-8");
        new String();
    } catch (Exception e1) {
        e1.printStackTrace();
    }
    return s;
}

*Unicode轉為字符串

/**
 * unicode 轉字符串
 */
public static String unicode2String(String unicode) {
    StringBuffer string = new StringBuffer();
    String[] hex = unicode.split("\\\\u");
    for (int i = 1; i < hex.length; i++) {
        // 轉換出每一個代碼點
        int data = Integer.parseInt(hex[i], 16);
        // 追加成string
        string.append((char) data);
    }
    return string.toString();
}

此方法雖然解決了轉化過程中中文亂碼的問題,但是過於復雜,筆者后來又發現一種新的轉化方式,可直接轉化,中文不亂碼,代碼如下:

　　*字符串轉16進制

 1 /**
 2  * 字符串轉換成為16進制(無需Unicode編碼)
 3  * @param str
 4  * @return
 5  */
 6 public static String str2HexStr(String str) {
 7     char[] chars = "0123456789ABCDEF".toCharArray();
 8     StringBuilder sb = new StringBuilder("");
 9     byte[] bs = str.getBytes();
10     int bit;
11     for (int i = 0; i < bs.length; i++) {
12         bit = (bs[i] & 0x0f0) >> 4;
13         sb.append(chars[bit]);
14         bit = bs[i] & 0x0f;
15         sb.append(chars[bit]);
16         // sb.append(' ');
17     }
18     return sb.toString().trim();
19 }

*16進制轉為字符串

 1 /**
 2  * 16進制直接轉換成為字符串(無需Unicode解碼)
 3  * @param hexStr
 4  * @return
 5  */
 6 public static String hexStr2Str(String hexStr) {
 7     String str = "0123456789ABCDEF";
 8     char[] hexs = hexStr.toCharArray();
 9     byte[] bytes = new byte[hexStr.length() / 2];
10     int n;
11     for (int i = 0; i < bytes.length; i++) {
12         n = str.indexOf(hexs[2 * i]) * 16;
13         n += str.indexOf(hexs[2 * i + 1]);
14         bytes[i] = (byte) (n & 0xff);
15     }
16     return new String(bytes);
17 }