java-自定义的进制转换-可以处理缩短uuid长度的问题

来源：互联网发布：淘宝开店如何装修编辑：程序博客网时间：2024/06/18 05:02

不多说，直接上代码

package main;import java.util.HashMap;import java.util.Map;/** * 处理进制的工具类 **/public class RadixUtil {    final static String NAME = RadixUtil.class.getName();    /**     * 产生进制的数字     **/    final static char[] DIGIT = {//            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', //            'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', //            'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', //            'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', //            'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', //            'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', //            '8', '9' //    };    final static Map<Character, Integer> digitMap = new HashMap<Character, Integer>();    static {        for (int i = 0; i < DIGIT.length; i++) {            digitMap.put(Character.valueOf(DIGIT[i]), Integer.valueOf(i));        }    }    /**     * 支持的最大进制数     */    public static final int MAX_RADIX = DIGIT.length;    /**     * 支持的最小进制数     */    public static final int MIN_RADIX = 2;    /**     * 最多一次返回32个字符     **/    public static final int SIZE = 32;    public static String toString(long i) {        return toString(i, MAX_RADIX);    }    /**     * 只用26个大写字母     **/    public static String toLetter(long i) {        return toString(i, 26);    }    /**     * 将长整型数值转换为指定的进制数（最大支持62进制）     */    public static String toString(long i, int radix) {        if (radix < MIN_RADIX || radix > MAX_RADIX) {            radix = 10;        }        if (radix == 10) {            return Long.toString(i);        }        StringBuilder sb = new StringBuilder(SIZE);        boolean negative = (i < 0);        if (negative) {            i = -i;        }        while (i >= radix) {            sb.append(DIGIT[(int) (i % radix)]);            i = i / radix;        }        sb.append(DIGIT[(int) (i)]);        if (negative) {            sb.append("-");        }        return sb.reverse().toString();    }    private static NumberFormatException forInputString(String s) {        return new NumberFormatException("For input string: \"" + s + "\"");    }    /**     * 将字符串转换为长整型数字     */    public static long toNumber(String s) {        return toNumber(s, MAX_RADIX);    }    public static long toNumberLetter(String s) {        return toNumber(s, 26);    }    /**     * 将字符串转换为长整型数字     */    public static long toNumber(String s, int radix) {        if (s == null) {            throw new NumberFormatException("null");        }        if (radix < MIN_RADIX) {            throw new NumberFormatException("radix " + radix + " less than " + NAME + ".MIN_RADIX");        }        if (radix > MAX_RADIX) {            throw new NumberFormatException("radix " + radix + " greater than " + NAME + ".MAX_RADIX");        }        // 返回结果        long result = 0;        char[] ss = s.toCharArray();        // 计算阶乘        long factorial = 1;        for (int i = (ss.length - 1); i >= 0; i--) {            char c = ss[i];            Integer v = digitMap.get(Character.valueOf(c));            if (v != null) {                result += v.intValue() * factorial;                factorial *= radix;            }        }        return result;    }}

调用的测试类

package main;import java.util.UUID;public class DMain {    public static void main(String[] args) {        UUID uuid = UUID.randomUUID();        System.out.println(uuid.toString());        long most = Math.abs(uuid.getMostSignificantBits());        String mosts, leasts;        long least = Math.abs(uuid.getLeastSignificantBits());        StringBuilder sb24 = new StringBuilder();        sb24 = new StringBuilder();        mosts = RadixUtil.toLetter(most);        sb24.append(mosts);        leasts = RadixUtil.toLetter(least);        sb24.append(leasts);        System.out.println(sb24.toString());        System.out.println("most:\n" + most);        System.out.println("mosts:\n" + mosts);        System.out.println("mosts-r:\n" + RadixUtil.toNumberLetter(mosts));        System.out.println("least:\n" + least);        System.out.println("leasts:\n" + leasts);        System.out.println("leasts-r:\n" + RadixUtil.toNumberLetter(leasts));    }}

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