5.1 获取字符串中某个字符串的最后一位的下标 publicclassStringUtils{publicstaticintgetLastIndexOf(StringtargetString,StringsubString){intlastIndex=targetString.lastIndexOf(subString);returnlastIndex!=-1?lastIndex+subString.length()-1:-1;}} 1. 2. 3. 4. 5. 6. 5.2 字符串拼接 publicclassStringUtils...