正则表达式（二）

今天花了一天时间，把正则表达式的内容看了一遍。下面是一个正则表达式的例子（是最基本的哦）。

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Test2 {

 public static void main(String[] args) {
  p("abc".matches("..."));
  p("a7856a".replaceAll("\\d", "-"));
  p("a7856a".replaceAll("[0-9]", "-"));
  Pattern p = Pattern.compile("\\d");
  Matcher m = p.matcher("a7856a");
  p(m.replaceAll("-"));
  Pattern p1 = Pattern.compile("[a-z]{3}");
  Matcher m1 = p1.matcher("fag");
  p(m1.matches());
  p("fagsa".matches("[a-z]{3}"));
  
  p("a".matches("."));
  p("aa".matches("aa"));
  p("aaa".matches("a*"));
  p("aaa".matches("a+"));
  p("aaa".matches("a?"));
  p("".matches("a*"));
  p("".matches("a?"));
  p("a".matches("a?"));
  p("2134567889456415231".matches("\\d{3,100}"));
  p("192.168.10.aaa".matches("\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}"));
  p("392".matches("[0-2][0-9][0-9]"));
  
  p("a".matches("[abc]"));
  p("a".matches("[^abc]"));
  p("A".matches("[a-z]|[A-Z]"));
  p("A".matches("[a-zA-Z]"));
  p("A".matches("[a-z[A-Z]]"));
  p("R".matches("[A-Z&&[RFG]]"));
  
  p(" aaad".matches("\\s{4}"));
  p(" ".matches("\\S"));
  p("a_8".matches("\\w{3}"));
  p("abc8855424524%^$".matches("[a-z]{1,3}\\d+[%^$]+"));
  p("\\".matches("\\\\"));
  
  p("a".matches("\\p{Lower}"));
  p("a".matches("\\p{Upper}"));
  
  p("hello sir".matches("^h.*"));
  p("hello sir".matches(".*ir$"));
  p("hello sir".matches("^h[a-z]{1,3}o\\b.*"));
  p("hellosir".matches("^h[a-z]{1,3}o\\b.*"));//单词边界
  p("hello sir".matches("^h[a-z]{1,3}o\\B.*"));//非单词边界
  
  p("".matches("^[\\s&&[^\\n]]*\\n$"));//空白行
  
  p("aaa 8888c".matches(".*\\d{4}."));
  p("aaa 8888c".matches(".*\\b\\d{4}."));
  p("aaa8888c".matches(".*\\d{4}."));
  p("aaa8888c".matches(".*\\b\\d{4}."));
  
  //email
  p("[e-mail]".matches("[\\w[.-]]+@[\\w[.-]]+\\.[\\w]+"));
  lookingAt
  Pattern p3 = Pattern.compile("\\d{3,5}");
  String s = "123-34345-234-00";
  Matcher m3 = p3.matcher(s);
  p(m3.matches());

  m3.reset();//重置匹配器
     p(m3.find());//找一个子串
     p(m3.start() + "-" + m3.end());
     p(m3.find());
     p(m3.start() + "-" + m3.end());
     p(m3.find());
     p(m3.start() + "-" + m3.end());
     p(m3.find());//false
    
     p(m3.lookingAt());
     p(m3.lookingAt());
     p(m3.lookingAt());
     p(m3.lookingAt());
     
     Pattern p4 = Pattern.compile("java",Pattern.CASE_INSENSITIVE);
     Matcher m4 = p4.matcher("java Java JAVa JaVa IloveJAVA you hateJava dsfsdafsadfa");
   p(m4.replaceAll("JAVA"));
    StringBuffer buf = new StringBuffer();
    int i=0;
    while(m4.find()) {
     i++;
     if (i % 2 == 0) {
      m4.appendReplacement(buf, "Java");
     } else {
      m4.appendReplacement(buf, "JAVA");
     }
    }
    m4.appendTail(buf);
    p(buf);
    
    //group
    Pattern p5 = Pattern.compile("(\\d{3,5})([a-z]{2})");

    String s5 = "123aa-34345bb-234cc-00";
    Matcher m5 = p5.matcher(s5);
    while(m5.find()) {
     //p(m5.group());
     p(m5.group(1));
     //p(m5.group(2));
    }
    
    Pattern p6 = Pattern.compile("(.{3,10}+)[0-9]");
    String s6 = "aaaa5bbb69";
    Matcher m6 = p6.matcher(s6);
    if(m6.find()) {
     p(m6.start() + "-" + m6.end());
    } else {
     p("not patch");
    }
   
    //non-capturing groups
    Pattern p7 = Pattern.compile(".{3}(?=a)");
    String s7 = "444a66b";
    Matcher m7 = p7.matcher(s7);
    while(m7.find()) {
     p(m7.group());
    }
   
    //向上引用
    Pattern p8 = Pattern.compile("(\\d\\d)\\1");
    String s8 = "1234";
    Matcher m8 = p8.matcher(s8);
    p(m8.matches());
   
    //flags的简写
    //Pattern p9 = Pattern.compile("java",Pattern.CASE_INSENSITIVE);
    p("Java".matches("(?i)(java)"));//与上面的写法完全一样
 }
 
 public static void p(Object o) {
  System.out.println(o);
 }

}