JAVAは正規表現を使う

package test;

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

public class RegTest {
	public static void main(String[] args)
	{
		Pattern reg = Pattern.compile("(20\\d{2})-([01]\\d)-([0-3]\\d)");
		Matcher matcher = null;
		System.out.println(reg.pattern());
		matcher = reg.matcher("2012-02-25");
		
		//matches()                 ，                    
		if (matcher.matches())
		{
			System.out.println("time:"+matcher.group(0));
			System.out.println("year:"+matcher.group(1));
			System.out.println("year:"+matcher.group(2));
			System.out.println("year:"+matcher.group(3));
		}
		
		Pattern reg2 = Pattern.compile("\\d*");
		System.out.println(reg2.pattern());
		matcher = reg2.matcher("2012abcd");
		
		//lookingAt()                    
		if (matcher.lookingAt())
		{
			System.out.println("num:"+matcher.group());
		}
		
		Pattern reg3 = Pattern.compile("\\d+");
		System.out.println(reg3.pattern());
		matcher = reg3.matcher("asf2012abcd2011jdf2010jk");
		
		//find()                    
		while(matcher.find())
		{
			System.out.println("matcherStr:"+matcher.group());
		}
		
		//appendReplacement()                ，                                 StringBuffer   
		Pattern reg4 = Pattern.compile("(hello|goodbye)");
		matcher = reg4.matcher("sayhelloandsaygoodbyeandsayhelloandsaysomething");
		StringBuffer sb = new StringBuffer();
		
		while (matcher.find()){
			System.out.println("matcherStr:"+matcher.group());
			matcher.appendReplacement(sb, "IT");
			System.out.println("sb:"+sb);
		}
		//appendTail()                         StringBuffer   
		//           appendReplacement                 
		matcher.appendTail(sb);
		System.out.println("sb:"+sb);
	}
}

(20\d{2})-([01]\d)-([0-3]\d)
time:2012-02-25
year:2012
year:02
year:25
\d*
num:2012
\d+
matcherStr:2012
matcherStr:2011
matcherStr:2010
matcherStr:hello
sb:sayIT
matcherStr:goodbye
sb:sayITandsayIT
matcherStr:hello
sb:sayITandsayITandsayIT
sb:sayITandsayITandsayITandsaysomething