国际码和内码的转换在线_区位码转国标码工具

国际码和内码的转换在线_区位码转国标码工具 我先考一考你，你说这个字符串（ab一2?仯3?4）有多少个字符？这时候你也许开始数了，123…9个，没错，确实我们肉眼确实是看到了9个，java代码如下：有没有发现java判断出来的不是9，而是12！！！那是因为这个字符串中有2个字符ab一2?仯3?4用黄色表示，实际上UTF-8已经满足不了，? 见下图：java的String是使用UTF-16来表示的，U+0000-U+FFFF都ok，但是只要是下列这个区间的字符都无法用常规手段处理，5位内码的，用length都无法正确判断其长度CJK Unified Ideographs Extension B (U+20000 through U+2A6DD)CJK Unified Ideographs Extension C (U+2A700 through U+2B734)CJK Unified Ideographs Extension D (U+2B740 through U+2B81D)CJK Unified Ideographs Extension E (U+2B820 through U+2CEA1)CJK Unified Ideographs Extension F (U+2CEB0 through U+2EBE0)具体也可以查看官方资料 ，了解unicode，UTF-8，UTF-16，UTF-32的区别。

如下图，可以通过Character中的codePointCount来得到字符数量。

进入主题jdk自带的Character类特别好用，汉字转内码，内码转汉字具体功能请参考下面的代码/** * 字符串转16进制内码 * @param str ab一2?仯3?4 * @return \u61\u62\u4e00\u32\u2b802\u4eef\u33\u2b82f\u34\u34 */public static String stringToCodePoints(String str) { StringBuilder stringBuilder = new StringBuilder(); str.codePoints().forEach(cp -> stringBuilder.append("\u").append(Integer.toHexString(cp))); return stringBuilder.toString();}/** * 内码转汉字 * @param codePoints \u61\u62\u4e00\u32\u2b802\u4eef\u33\u2b82f\u34\u34 * @return ab一2?仯3?4 */public static String codePointsToString(String codePoints) { StringBuilder stringBuilder = new StringBuilder(); for(String hexCodePoint : codePoints.split("\\u")){ if(StringUtils.isNotBlank(hexCodePoint)) { stringBuilder.append(codePointToString(Integer.parseInt(hexCodePoint, 16))); } } return stringBuilder.toString();}/** * 十进制转汉字 * @param cp code point 汉字内码 * @return */public static String codePointToString(int cp) { StringBuilder sb = new StringBuilder(); if (Character.isBmpCodePoint(cp)) { sb.append((char) cp); } else if (Character.isValidCodePoint(cp)) { sb.append(Character.highSurrogate(cp)); sb.append(Character.lowSurrogate(cp)); } else { sb.append('?'); } return sb.toString();}支持5位编码的在线转换工具