正则表达式 

  1 package regex;
  2 
  3 import java.util.regex.Matcher;
  4 import java.util.regex.Pattern;
  5 
  6 /**
  7  * 正则表达式
  8  * @author XSW
  9  *
 10  */
 11 public class Test {
 12 
 13     
 14     public static void main(String[] args) {
 15         //正则表达式
 16         /*System.out.println("asd".matches("..."));
 17     
 18         p("a8888634a".replaceAll("\\d", "--"));
 19         
 20         Pattern pattern = Pattern.compile("[a-z]{3}");
 21         
 22         Matcher matcher = pattern.matcher("cde");
 23         
 24         p(matcher.matches());
 25         
 26         p("add".matches("[a-z]{3}"));
 27     */
 28         
 29         //认识一下 . * ? +
 30         
 31     /*    p("a".matches("."));
 32         p("aaa".matches("aaa"));
 33         p("aaa".matches("a*"));
 34         p("aaa".matches("a?"));
 35         p("".matches("a?"));
 36         p("aaa".matches("a+"));
 37         p("".matches("a*"));
 38         p("aaaaa".matches("a*"));
 39         p("1234213434254356623523".matches("\\d{3,100}"));
 40         p("192.136.22a".matches("\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}"));
 41         p("192".matches("[0-2][0-9][0-9]"));
 42         */
 43         
 44         //范围
 45         /*p("a".matches("[a-z]"));
 46         p("a".matches("[^abc]"));
 47         p("A".matches("[a-zA-Z]"));
 48         p("A".matches("[a-z]|[A-Z]"));
 49         p("A".matches("[a-z[A-Z]]"));
 50         p("A".matches("[A-Z&&[ARF]]"));
 51         p("R".matches("[A-Z&&[RFG]]"));
 52         p("X".matches("[A-Z&&[ARF]]"));
 53         */
 54         //认识 \s \w \d \
 55     /*    p(" \t\n\f".matches("\\s{4}"));
 56         p(" ".matches("\\S"));
 57         p("asd_123".matches("\\w{7}"));
 58         p("abc333&^$".matches("[a-z]{3}\\d+[&^$]+"));
 59         p("\\".matches("\\\\"));
 60         */
 61         
 62         //边界
 63         /*p("hello world".matches("^h.*"));
 64         p("hello world".matches("^.*ld$"));
 65         p("hello world".matches("^h[ell]{1,3}o*"));
 66         p("hello world".matches("^h[ell]{1,3}o [\\w]*"));
 67         
 68         p("hello world".matches("^h[a-z]{1,3}o\\b.*"));
 69         p("helloworld".matches("^h[a-z]{1,3}o\\b.*"));*/
 70         //空白行
 71         /*p(" \n".matches("^[\\s&&[^\\n]]*\\n$"));*/
 72         //Email
 73         //p("asdfskfjgslakhjghjkj@hdjksfk.com".matches("[\\w[.-]]+@[\\w[.-]]+\\.[\\w]+"));
 74         //matches find lookingAt
 75         /**
 76          * matches 永远匹配整个字符串
 77          * find 找子串  当和matches一起用时有影响，可以使用reset()，使其回复原始状态，在用find
 78          * lookingAt  永远从头开始找
 79          */
 80         
 81         /*Pattern pattern = Pattern.compile("\\d{3,5}");
 82         Matcher m= pattern.matcher("123-33453-234-00");
 83         
 84         p(m.matches());
 85         
 86         m.reset();
 87         
 88         p(m.find());*/
 89         /*
 90          * start()是找到子串的起始位置，
 91          * end()是找到的子串的末尾位置的下一个位置
 92          */
 93         /*System.out.println(m.start()+"--"+m.end());
 94         p(m.find());
 95         System.out.println(m.start()+"--"+m.end());
 96         p(m.find());
 97         System.out.println(m.start()+"--"+m.end());
 98         p(m.find());*/
 99         /*
100          * 子串必须找到才能输出位置信息
101          * 
102          */
103         //System.out.println(m.start()+"--"+m.end());
104 
105         /*p(m.lookingAt());
106         p(m.lookingAt());
107         p(m.lookingAt());
108         p(m.lookingAt());*/
109         
110         //replacement （替换）
111         
112         /*Pattern pattern = Pattern.compile("java");
113         Matcher m = pattern.matcher("java Java JaVA JAva ILoveJava you hateJava");
114         
115         while(m.find()){
116             p(m.group());
117         }*/
118         
119     /*    Pattern pattern = Pattern.compile("java",Pattern.CASE_INSENSITIVE);
120         Matcher m = pattern.matcher("java Java JaVA JAva ILoveJava you hateJava");
121         //替换成大写JAVA
122         p(m.replaceAll("JAVA"));*/
123         //奇数位置上为大写，偶数上为小写
124         /*Pattern pattern = Pattern.compile("java",Pattern.CASE_INSENSITIVE);
125         Matcher m = pattern.matcher("java Java JaVA JAva ILoveJava you hateJava fdjsfkjasgfhlkjhgefs");
126         StringBuffer buffer = new StringBuffer();
127         int i = 0;
128         while(m.find()){
129             i++;
130             if(i%2 == 0){
131                 m.appendReplacement(buffer, "java");
132             }else{
133                 m.appendReplacement(buffer, "JAVA");
134             }
135         }
136         m.appendTail(buffer);
137         p(buffer);*/
138         
139         //分组（group()）
140         /*Pattern pattern = Pattern.compile("\\d{3,5}[a-z]{2}");
141         Matcher m = pattern.matcher("123as-14324ni-890hh-00");
142         while(m.find()){
143             p(m.group());
144         }*/
145         //进行分组，分组规则compile("(\\d{3,5})([a-z]{2})")在原来的分组规则上我加上了括号进行分组，(\\d{3,5})数字为一组  ([a-z]{2})字母为一组；
146         //怎么看是第几组，要看小括号的左半边数起compile("(\\d{3,5})([a-z]{2})")这个总共有三个左半边，分别为第0组数字字母组，第1组数字组，第2组字母组；什么够不填默认为0
147         Pattern pattern = Pattern.compile("(\\d{3,5})([a-z]{2})");
148         Matcher m = pattern.matcher("123as-14324ni-890hh-00");
149         while(m.find()){
150             p(m.group(2));
151         }
152     
153     }
154     
155     public static void p(Object object){
156         
157         System.out.println(object);
158     }
159 }

 

posted @ 2018-03-30 19:51  慕容天白  阅读(171)  评论(0)  编辑  收藏  举报