java 正则匹配空格字符串 正则表达式截取字符串

时间:2021-11-05 01:00:22

java 正则匹配空格字符串 正则表达式截取字符串

需求:从一堆sql中取出某些特定字符串:

比如配置的sql语句为:"company_code = @cc and project_id = @pid ; update t set a = @aa,b=@bb,c=@cd,ttt=@ttt;update t2 set d=@bb";

我要拿出所有的以@开头的作为变量,并且去重,则如下玩:

ps:其中正则匹配空格是 “\s+”

public class Test {
public static void main(String[] args) {
//String input = "update t set a = @aa,b=@bb,c=@cd,ttt=@ttt;update t2 set d=@bb";
String input = "company_code = @cc and project_id = @pid ; update t set a = @aa,b=@bb,c=@cd,ttt=@ttt;update t2 set d=@bb"; String patternStr = "(\\s*=\\s*)|(\\s*,\\s*)|(\\s*;\\s*)|(\\s+)";
Pattern pattern = Pattern.compile(patternStr);
String[] dataArr = pattern.split(input);
Set<String> set = new TreeSet<String>();
for (String str : dataArr) {
System.out.println(str);
if (str.startsWith("@")) {
str = str.replaceAll("@", "");
set.add(str);
}
}
System.out.println(set);
}

[aa, bb, cc, cd, pid, ttt]输出如下:

截图如下:

后来又优化了一下,既然是找出以@开头的,那么再换一个正则:

public class Tst {
public static void main(String[] args) {
//String input = "update t set a = @aa,b=@bb,c=@cd,ttt=@ttt;update t2 set d=@bb";
String input = "company_code = $csc223@cc and project_id = @pid ; update t set a = @aa,b=@cd,c=@cd,ttt=@ttt;update t2 set d=@bb"; String regex = "@\\w+\\s?";
//regex = "(\\s*=\\s*)|(\\s*,\\s*)|(\\s*;\\s*)|(\\s+)";
Pattern pattern = Pattern.compile(regex);
Matcher matcher = pattern.matcher(input);
Set<String> set = new TreeSet<String>(); while(matcher.find()){
set.add(matcher.group());
}
System.out.println(set);
}
}

2014年11月26日 16:50:31

2015年 2月10日  23:43:45

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