要使用ANTLR匹配字符串中的日期时间,您可以按照以下步骤操作:
grammar DateTime;
date: (day WS month WS year) | (month WS day WS year);
time: hours ':' minutes (':' seconds)?;
datetime: date WS time?;
day: [0-9]+;
month: 'January' | 'February' | 'March' | ... | 'December';
year: [0-9]+;
hours: [0-9]+;
minutes: [0-9]+;
seconds: [0-9]+;
WS: [ \t\r\n]+ -> skip;
antlr -visitor DateTime.g4
这将生成DateTimeParser.java和DateTimeLexer.java文件。
import org.antlr.v4.runtime.*;
import org.antlr.v4.runtime.tree.*;
public class DateTimeListener extends DateTimeBaseListener {
@Override
public void enterDatetime(DateTimeParser.DatetimeContext ctx) {
System.out.println("Datetime: " + ctx.getText());
}
@Override
public void enterDate(DateTimeParser.DateContext ctx) {
System.out.println("Date: " + ctx.getText());
}
@Override
public void enterTime(DateTimeParser.TimeContext ctx) {
System.out.println("Time: " + ctx.getText());
}
// Other listener methods for day, month, year, hours, minutes, and seconds
}
public class Main {
public static void main(String[] args) throws Exception {
String input = "January 1, 2022 12:34:56";
DateTimeLexer lexer = new DateTimeLexer(CharStreams.fromString(input));
DateTimeParser parser = new DateTimeParser(new CommonTokenStream(lexer));
ParseTreeWalker walker = new ParseTreeWalker();
DateTimeListener listener = new DateTimeListener();
walker.walk(listener, parser.datetime());
}
}
Datetime: January 1, 2022 12:34:56
Date: January 1, 2022
Time: 12:34:56
通过这种方法,您可以使用ANTLR匹配字符串中的日期时间,并对其进行进一步处理。
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