1、首先随便给你一个含有数字的字符串，比如：String s="eert343dfg56756dtry66fggg89dfgf";要提取数字有三种方法正则表达式，集合类，还有就是String类提供的方法。
2、String类提供package 测试练习;import Java.ut坡纠课柩il.*;public class get_StringNum {/***2016.10.25*/public static void main(String[] args) {String str = "love23next234csdn3423javaeye";str=str.trim();String str2="";if(str != null && !"".equals(str)){for(int i=0;i<str.length();i++){if(str.charAt(i)>=48 && str.charAt(i)<=57){str2+=str.charAt(i);}}}System.out.println(str2);}}output:232343423
3、正则表达式import java.util.*;import java.util.regex.Matcher;import java.util.regex.Pattern;public class get_StringNum {/***2016.10.25*/public static void main(String[] args) {String a="love23next234csdn3423javaeye";String regEx="[^0-9]";Pattern p = Pattern.compile(regEx);Matcher m = p.matcher(a);System.out.println( m.replaceAll("").trim());}}output:232343423
4、集合类库import java.util.*;import java.util.regex.Matcher;import jav锾攒揉敫a.util.regex.Pattern;public class get_StringNum {/***2016.10.25*/public static void main(String[] args) {String a="love23next234csdn3423javaeye";List<String> digitList = new ArrayList<String>();Pattern p = Pattern.compile("[^0-9]");Matcher m = p.matcher(a);String result = m.replaceAll("");for (int i = 0; i < result.length(); i++) {digitList.add(result.substring(i, i+1));}System.out.println(digitList);}}output:[2, 3, 2, 3, 4, 3, 4, 2, 3]
