root/trunk/myweb/src/mypackage/StringTest.java

package mypackage;

import java.util.regex.*;

public class StringTest {
  public static void main(String[] args) {
    StringBuffer sb=new StringBuffer("文字列の始まり");
    if (true) sb.append("場合1");
    else sb.append("場合2");
    sb.append("終わり");
    System.out.println(sb.toString());

    String str="<h3>文字列</h3><p>文字列を扱うには（中略）</p>"
              +"<H3>正規表現</h3><P>先に説明したStringや\n（後略）</p>";
    //Pattern p=Pattern.compile("(?i:<h3>.*?</h3>)");
    //Pattern p=Pattern.compile("(?is:<p>.*?</p>)");
    Pattern p=Pattern.compile("(<p>.*?</p>)",Pattern.CASE_INSENSITIVE|Pattern.DOTALL);
    Matcher m=p.matcher(str);
    while (m.find()) System.out.println(m.group());

    String[] strs={"aaXbbXX", "cXXd", "eXXXf"};
    for (String s:strs) System.out.println(s.replaceAll("X+","Z"));

    String[] strs2={
      "yabuki@example.com",
      "taro@example.org",
      "taro.yabuki@unfindable.net"
    };

    for (String s:strs2)
      System.out.println(s.replaceFirst("(.+)@.+\\.(.+)","$1 のドメインは $2"));

    Pattern p2=Pattern.compile("(.+)@.+\\.(.+)");
    Matcher m2;
    for (String s:strs2) {
      m2=p2.matcher(s);
      m2.find();
      System.out.println(m2.group(1)+" のドメインは "+m2.group(2));
    }
  }
}