package com.ynet.utils;import java.util.regex.Matcher;
import java.util.regex.Pattern;/*** Created by Arya on 2017/11/3 0003.*/
public class StringUtil {//去除所有空格public static String replaceAllBlank(String str) {String s = "";if (str!=null) {Pattern p = Pattern.compile("\\s*|\t|\r|\n");/*\n 回车(\u000a)\t 水平制表符(\u0009)\s 空格(\u0008)\r 换行(\u000d)*/Matcher m = p.matcher(str);s = m.replaceAll("");}return s;}//去除所有空格，留下一个public static String replaceBlankLeaveOne(String str) {String s = "";if (str!=null) {Pattern p = Pattern.compile("\\s{2,}|\t|\r|\n");Matcher m = p.matcher(str);s = m.replaceAll(" ");}return s;}public static void main(String[] args) {System.out.println(StringUtil.replaceAllBlank("just    do     it!"));System.out.println(StringUtil.replaceBlankLeaveOne("just    do     it!"));}}

运行效果：