RegexpTest.java

package converter;

import org.junit.Assert;
import org.junit.Test;

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

public class RegexpTest {

    String input = "<li><a href=\"../../jbatch/hello/\" >anchor</a></li>";
    String expected = "<li><a href=\"/entry/articles-jbatch-hello\" >anchor</a></li>";

    @Test
    public void numberedGroups() {
        Pattern p = Pattern.compile("(<a href=\")\\.\\./\\.\\./(.*)/(.*)/\"");
        Matcher matcher = p.matcher(input);
        String result = matcher.replaceAll("$1/entry/articles-$2-$3\"");
        Assert.assertEquals(expected, result);
    }

    @Test
    public void namedGroups() {
        Pattern p = Pattern.compile("(?<prefix><a href=\")\\.\\./\\.\\./(?<category>.*)/(?<handle>.*)/\"");
        Matcher matcher = p.matcher(input);
        String result = matcher.replaceAll("${prefix}/entry/articles-${category}-${handle}\"");
        Assert.assertEquals(expected, result);
    }

    @Test
    public void appendReplacement() {
        Pattern p = Pattern.compile("(?<prefix><a href=\")(?<url>.*)\"");
        Matcher matcher = p.matcher(input);
        StringBuffer sb = new StringBuffer();
        while (matcher.find()) {
            // any complex logic can be placed here
            String url = matcher.group("url");
            String[] urls = url.split("/");
            matcher.appendReplacement(sb, "${prefix}/entry/articles-" + urls[2] + "-" + urls[3] + "\"");
        }
        matcher.appendTail(sb);
        String result = sb.toString();
        Assert.assertEquals(expected, result);
    }

    @Test
    public void escapeSpecialChars() {
        String input = "../../jbatch/hello/";
        String expected = "../../$1/${name}/";
        Pattern p = Pattern.compile("(?<prefix>\\.\\./\\.\\.)/.*/.*/");
        String result = p.matcher(input).replaceAll("${prefix}/" + Matcher.quoteReplacement("$1/${name}") + "/");
        Assert.assertEquals(expected, result);
    }
}