在Java中使用正则表达式获取关键字

我们可以利用正则表达式获取一个程序中的所有关键字。关键是正确使用单词边界。比如，给出“static staticFiled”，第一个单词应该被认为是关键字，而第二个不是。

import java.util.regex.Matcher;import java.util.regex.Pattern;import org.apache.commons.lang.StringUtils; public class RegTest {public static void main(String[] args) {String keyString = "abstract assert boolean break byte case catch "+ "char class const continue default do double else enum"+ " extends false final finally float for goto if implements "+ "import instanceof int interface long native new null " + "package private protected public return short static "+ "strictfp super switch synchronized this throw throws true " + "transient try void volatile while";String[] keys = keyString.split(" ");String keyStr = StringUtils.join(keys, "|"); String regex = "\\b("+keyStr+")\\b";String target = "static public staticpublic void main()";Pattern p = Pattern.compile(regex);Matcher m = p.matcher(target); while(m.find()){System.out.println("|"+m.group()+"|");System.out.println(m.start());System.out.println(m.end());}}}