关于“将字符串中相邻相同的子串合并为一个子串的代码”实现

?在网上看到一个面试题，要求

?因为最近在看js的正则表达式，觉得java也是可以实现的,结果碰巧就实现了。用了两种方法，可其实原理都是一样的。个人觉得这样写效率比较高，各位觉得呢？

package regex;import java.util.regex.Matcher;import java.util.regex.Pattern;/** * 将字符串中相邻相同的子串合并为一个子串，如"12342343454565678789" -- "123456789" */public class StringMerge {public static void main(String[] args) {// System.out.println(tt(6));mergeString2("1234234345456567878911111111111111112343333333333");System.out.println("----");mergeString("1234234345456567878911111111111111112343333333333");}public static void mergeString(String str) {String regex = "(\\d+)\\1";String temp1 = replace(regex, str);int len2 = str.length();while (temp1.length() != len2) {//System.out.println(len2 + "--" + temp1.length());len2 = temp1.length();temp1 = replace(regex, temp1);}System.out.println("方法一:"+temp1);}/** * 用appendReplacement ..方法一： * @param str */public static String replace(String regex, String str) {Pattern p = Pattern.compile(regex);Matcher m = p.matcher(str);StringBuffer sb = new StringBuffer();while (m.find()) {m.appendReplacement(sb, "$1");}m.appendTail(sb);//System.out.println(sb.toString());return sb.toString();}public static void mergeString2(String str) {String regex = "(\\d+)\\1";String temp1 = replace2(regex, str);int len2 = str.length();while (temp1.length() != len2) {//System.out.println(len2 + "--" + temp1.length());len2 = temp1.length();temp1 = replace2(regex, temp1);}System.out.println("方法一:"+temp1);}/** * 用replaceAll实现，方法二： * @param regex * @param str * @return */public static String replace2(String regex, String str) {Pattern p = Pattern.compile(regex);Matcher m = p.matcher(str);String temp = m.replaceAll("$1");return temp;}}

?