java 正则

mac2022-06-30 87

1. matches() 匹配全部

Pattern p = Pattern.compile("reg");

Matcher m = p.matcher("String");

System.out.println(m.matches());

2:(matches 和find不要一起用,用reset()吐出来)

　find()匹配部分

while(m.find()){

　　SYstem.out.println(m.group());//group() 每次循环 find()匹配到的部分

}

replaceAll() 替代匹配的所有

System.out.println(m.replaceAll("java"));

比replaceAll()更灵活的替换appendReplacement(StringBuffer sb,String yourString);

//把偶数index的java 替换为"猫叔";

StringBuffer sb = new StringBuffer(); int i=0; while(m.find()){ i++; if(i%2==0){ m.appendReplacement(sb, "猫叔"); } } m.appendTail(sb); System.out.println(sb);

3.更强大的分组()()式

/*Pattern p2 = Pattern.compile("([\\w[-._.]]+)(@[\\w[\\d]]+\\.[\\w]+)"); Matcher m2 =p2.matcher("-newobj_1@163.com,newobj@163.com,1299291758@qq.com"); while(m2.find()){ System.out.println(m2.group(1)); }*/

4.实际应用(爬email)

...所有以上的内容如下:

package first;

import java.io.BufferedReader;import java.io.File;import java.io.FileReader;import java.io.IOException;import java.util.regex.Matcher;import java.util.regex.Pattern;

public class T1 {

/** * @param args */ public static void main(String[] args) { //认识\s：space, \w: [a-zA-Z_0-9] , \d:[0-9] //System.out.println(" \r\n\t".matches("\\s{4}")); //System.out.println("hello sir".matches(".*sir$")); //System.out.println("newobj@163.com".matches("[\\w[_.]]+@[\\w[_.]]+\\.[\\w[_.]]+")); /*Pattern p = Pattern.compile("[\\d]{3,5}"); String tt = "123-2345-33333-00-12"; Matcher m = p.matcher(tt); System.out.println(m.matches()); m.reset(); System.out.println(m.find()); System.out.println(m.find()); System.out.println(m.find()); System.out.println(m.find());*/ //看group(当前匹配的结果)以及repalceAll; Pattern p = Pattern.compile("java",Pattern.CASE_INSENSITIVE); String a = "I lova java ,he heats Java, hanmeimei love JAva too , and you about java ?"; Matcher m = p.matcher(a);// while(m.find()){// System.out.println(m.group());// } //System.out.println(m.replaceAll("java")); //把偶数index的java 替换为"猫叔"; /*StringBuffer sb = new StringBuffer(); int i=0; while(m.find()){ i++; if(i%2==0){ m.appendReplacement(sb, "猫叔"); } } m.appendTail(sb); System.out.println(sb);*/ //看看更强大的group /*Pattern p2 = Pattern.compile("([\\w[-._.]]+)(@[\\w[\\d]]+\\.[\\w]+)"); Matcher m2 =p2.matcher("-newobj_1@163.com,newobj@163.com,1299291758@qq.com"); while(m2.find()){ System.out.println(m2.group(1)); }*/ //爬email BufferedReader bfr = null; try{ bfr = new BufferedReader(new FileReader(new File("D:/大家留下email吧.htm"))); String line =""; String myemail = "newobj@163.com"; Pattern pemail = Pattern.compile("[\\w_-]+@[\\w\\d]+\\.[\\w]+"); Matcher meail = null; //meail = pemail.matcher(myemail); //System.out.println(meail.matches()); while((line=bfr.readLine())!=null){ meail = pemail.matcher(line); while(meail.find()){ System.out.println(meail.group()); } } }catch (Exception e) { e.printStackTrace(); }finally{ try { bfr.close(); } catch (IOException e) { e.printStackTrace(); } } }

}

转载于:https://www.cnblogs.com/yanjunwu/p/3764067.html