JAVASE基础模块十九（正则表达式）

• 传统方法校验qq号

* 校验qq号
* 5-15位数字
* 0 不能开头
import java.util.Scanner;
public class Zheng {public static void main(String[] args) {Scanner s=new Scanner(System.in);System.out.println("输入qq号");String qqNumber = s.nextLine();boolean f=checkNumber(qqNumber);PanDuan(f);}private static boolean checkNumber(String qqNumber) {boolean flag=false;if(qqNumber.length()>=5&&qqNumber.length() <= 15&&!qqNumber.startsWith("0")){for (int i = 0; i < qqNumber.length(); i++) {char cc=qqNumber.charAt(i);if(Character.isDigit(cc)){flag=true;break;}else {flag=false;}}}return flag;}
}
输入qq号
0258
格式错误Process finished with exit code 0

• 传统方法校验手机号

import java.util.Scanner;
public class ShouJi {public static void main(String[] args) {Scanner s=new Scanner(System.in);System.out.println("输入号");String qqNumber = s.nextLine();boolean f=checkNumber(qqNumber);PanDuan(f);}private static void PanDuan(boolean f) {if(f==false){System.out.println("格式错误");}else {System.out.println("d");}}private static boolean checkNumber(String qqNumber) {boolean flag=false;if(qqNumber.length()==11&&qqNumber.startsWith("13")||qqNumber.startsWith("15")||qqNumber.startsWith("17")||qqNumber.startsWith("18")){for (int i = 2; i < qqNumber.length(); i++) {char cc=qqNumber.charAt(i);if(Character.isDigit(cc)){flag=true;}else {flag=false; break;}}}return flag;}
}
运行结果：
输入号
13546464646
dProcess finished with exit code 0

• 传统方法校验邮箱

import java.util.Scanner;public class YouXianng {public static void main(String[] args) {Scanner s = new Scanner(System.in);System.out.println("输入号");String you = s.nextLine();boolean f = checkN(you);PanDuan(f);}private static boolean checkN(String w) {boolean f = false;if (w.length() >= 14 && w.length() <= 26 && w.endsWith("@163.com")) {if (Character.isLetter(w.charAt(0))) {for (int i = 1; i < w.length() - 8; i++) {char cc = w.charAt(i);if (Character.isDigit(cc) || Character.isLetter(cc) || cc == '_') {f = true;} else {f = false;break;}}}}return f;}private static void PanDuan(boolean f) {if (f == false) {System.out.println("格式错误");} else {System.out.println("格式正确");}}
}
运行结果：
输入号
ss55gg__pp@163.com
格式正确Process finished with exit code 0

正则表达式

public class ZhengZe {public static void main(String[] args) {//定义正则表达式String regx = "a";String regx0 = "[a,b,c]";//是列举的某一个String regxf = "[a-z]";String regxx = "[a-zA-Z0-9]";String regx1 = "[0-9]";String regx2 = "[^0-9]";//^不是列举的某一个String regx4 = ".";//配置任意单个字符String regx3 = "\\.";//转义 \转义字符String regx5 = "|";//| 或者String regx6 = "\\|";//转义 | 它本身String regx7 = "\\d";//代表[0-9] 是0-9String regx8 = "\\D";//代表^[0-9] 不是0-9String regx9 = "\\w";//代表[a-zA-Z_0-9]String regx11 = "\\W";//代表^[a-zA-Z_0-9]String regx12 = " ";//代表空格String regx13 = "\\s";//也代表空格String regx14 = "\\S";//代表^空格 不是空格String regx15 = "abc$";//以abc整体结尾String regx16 = "^abc";//以abc整体开头String regx17 = "[0-9]+";//[0-9]+ 可以出现一个或多个String regx18 = "[a-z]*";//[a-z]* 可以出现零个或多个 一个也算多个 空串算零个String regx19 = "[A-Z]?"; //?  一个或零个String regx20 = "\\w+"; //?  一个或零个String regx2l = "[a-zA-Z0-9_]+"; //?  一个或零个String regx21 = "[a-z]{6}";//正好几个String regx22 = "[a-zA-Z]{6,}";//至少几个String regx23 = "[a-zA-Z]{6,16}";//6-16个//区分 System.out.println("abc".equals(regx));System.out.println("A".matches(regx));System.out.println("d".matches(regx));System.out.println("Aa".matches(regx));System.out.println("2".matches(regx1));System.out.println("2".matches(regx2));}
}

• qq号

  String regex="[1-9][0-9]{4,14}";

• 手机号

tring regex="[1][3,5,7,8][0-9]{9}";

• 邮箱

   String regex="[a-zA-Z][a-zA-Z0-9_]{5,17}@163.com$";
  

• v.split("\+"); 根据正则切割字符串

  import java.util.Arrays;public class Ty {public static void main(String[] args) {String v="半缘修道半缘君+衣带渐宽终不悔+惊起一滩鸥鹭";System.out.println(v.substring(0, v.indexOf("+")));System.out.println(v.substring(v.indexOf("+")+1, v.lastIndexOf("+")));System.out.println(v.substring(v.lastIndexOf("+")+1));//根据正则来切割这个字符串 返回的是一个字符串数组String[] s=v.split("\\+");System.out.println(Arrays.toString(s));}
  }
  

• 排序实例

import java.util.Arrays;public class Gh {public static void main(String[] args) {String v = "15      69  85  44  7  569 22 10 23 66 99";String[] s = v.split("\\s+");System.out.println(Arrays.toString(s));int[] a = new int[s.length];for (int i = 0; i < s.length; i++) {a[i] = Integer.valueOf(s[i]);}System.out.println(Arrays.toString(a));Arrays.sort(a);System.out.println(Arrays.toString(a));String ss = new String();for (int i = 0; i < a.length; i++) {ss += a[i] + " ";}System.out.println(ss);}
}
运行结果：
[15, 69, 85, 44, 7, 569, 22, 10, 23, 66, 99]
[15, 69, 85, 44, 7, 569, 22, 10, 23, 66, 99]
[7, 10, 15, 22, 23, 44, 66, 69, 85, 99, 569]
7 10 15 22 23 44 66 69 85 99 569 进程已结束,退出代码0

• replaceAll()

public class Rep {public static void main(String[] args) {String s="456aw489dwa半fiuaefhi缘fahf" +"ua修道半fahuaf缘fehaf君，gusfeegfyue" +"12356efae衣af带fae渐456宽45终af不78" +"9悔，feafaefaedfaq惊起fw" +"ab一fddfvd滩48987653鸥鹭";//根据正则表达式去替换System.out.println(s.replaceAll("[a-zA-Z0-9]+", ""));}
}
运行结果：
半缘修道半缘君，衣带渐宽终不悔，惊起一滩鸥鹭进程已结束,退出代码0

• 匹配器 Matcher与模式器 Pattern

import java.util.regex.Matcher;
import java.util.regex.Pattern;public class PiPeiQi {public static void main(String[] args) {//匹配器 Matcher//模式器 Pattern//把一个正则表达式封装到模式器里面Pattern p=Pattern.compile("a*b");//调用模式器中的matcher("aaaaaaab");方法 传入一个待匹配的数据Matcher m = p.matcher("aaaaaaab");//调用匹配器中的匹配方法 看数据是否匹配正确System.out.println(m.matches());//如果需求只是看一个数据符不符合一个正则 只需要调用string 类中的matches("a*b")System.out.println("aaaaaaab".matches("a*b"));}
}
运行结果：
true
true进程已结束,退出代码0

• matcher.find() matcher.group() 可以一直查找下去 并输出上次查找到的结果

  import java.util.regex.Matcher;
  import java.util.regex.Pattern;public class Pm {public static void main(String[] args) {String d="dg duo  gduwa hsefh hvjh bao huisah hvsd bao haud bjds wob axx h sh ia csvb jzvc ";String regx="\\b[a-z]{3}\\b";Pattern pattern = Pattern.compile(regx);Matcher matcher = pattern.matcher(d);System.out.println();//可以一直查找下去 并输出上次查找到的结果while (matcher.find()) {String s=matcher.group();System.out.print(s+"\t");}}
  }
  运行结果：
  duo	bao	bao	wob	axx	
  进程已结束,退出代码0
  

待续…