Java正则表达式学习

1、给定一个字符串判断是否为一定的格式

可以直接调用String.matches()方法判断或是用Pattern.compile()和Pattern.matcher()来判断。

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

public class PatternTest {

	public static void main(String[] args) {
		
		Scanner s = new Scanner(System.in);
		while(s.hasNext())
		{
			String str = s.next();
			Pattern p1 = Pattern.compile("\\d{4}-\\d{1,2}-\\d{1,2}");
			Matcher m1 = p1.matcher(str);
			Pattern p2 = Pattern.compile("\\d{1,2}/\\d{1,2}/\\d{4}");
			Matcher m2 = p2.matcher(str);
			if(str.matches("[1]+[01]+"))
			{
				System.out.println(str+"is a binary number");
			}else
			{
				System.out.println(str+"is not a binary number");
			}
			if(m1.matches()||m2.matches())
			{
				System.out.println(str+"is a legal date");
			}
			else{
				System.out.println(str+"is a illegal date");
			}
		}
		
	}

}