org.codehaus.mojo.license.osgi.AboutFileLicenseResolver.java Source code

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Here is the source code for org.codehaus.mojo.license.osgi.AboutFileLicenseResolver.java

Source

package org.codehaus.mojo.license.osgi;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.jar.JarFile;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.ZipEntry;

import org.apache.commons.io.IOUtils;
import org.apache.maven.model.License;
import org.codehaus.mojo.license.ext.LicenseFactory;
import org.codehaus.plexus.component.annotations.Component;

@Component(role = AboutFileLicenseResolver.class, hint = "default")
public class AboutFileLicenseResolver {

    private static final String ABOUT_HTML = "about.html";
    private static final String FILENAME_PATTERN_STR = "<a\\s+href=\"about_files/(\\S+)\"(.*?)>";
    private static final Pattern FILENAME_PATTERN = Pattern.compile(FILENAME_PATTERN_STR, Pattern.DOTALL);

    public List<License> resolve(String artifactId, File file) throws IOException {
        List<License> licenses = new ArrayList<License>();
        JarFile jarFile = new JarFile(file);
        try {
            ZipEntry entry = jarFile.getEntry(ABOUT_HTML);
            if (entry != null) {
                licenses.add(createJarEmbeddedLicense(artifactId, file, ABOUT_HTML));
                String content = readContent(jarFile, entry);
                licenses.addAll(findThrirdPartyLicenses(artifactId, file, content));
            }
            return licenses;
        } finally {
            jarFile.close();
        }
    }

    private List<License> findThrirdPartyLicenses(String artifactId, File file, String content)
            throws MalformedURLException {
        List<License> licenses = new ArrayList<License>();
        for (String licenseFilename : findLicenseFilenames(content)) {
            License license = createJarEmbeddedLicense(artifactId, file, "about_files/" + licenseFilename);
            licenses.add(license);
        }
        return licenses;
    }

    private License createJarEmbeddedLicense(String artifactId, File file, String localPath)
            throws MalformedURLException {
        URL url = toJarUrl(file, localPath);
        return LicenseFactory.create(artifactId, url.toString());
    }

    private URL toJarUrl(File file, String localPath) throws MalformedURLException {
        URL fileUrl = file.toURI().toURL();
        return new URL("jar", "", fileUrl.toString() + "!/" + localPath);
    }

    private List<String> findLicenseFilenames(String content) {
        return findGroupOccurrences(content, FILENAME_PATTERN, 1);
    }

    private List<String> findGroupOccurrences(String content, Pattern pattern, int groupNumber) {
        List<String> matches = new ArrayList<String>();
        Matcher matcher = pattern.matcher(content);
        while (matcher.find()) {
            if (groupNumber <= matcher.groupCount()) {
                matches.add(matcher.group(groupNumber));
            }
        }
        return matches;
    }

    private String readContent(JarFile jarFile, ZipEntry entry) throws IOException {
        InputStream inputStream = jarFile.getInputStream(entry);
        StringWriter writer = new StringWriter();
        IOUtils.copy(inputStream, writer, StandardCharsets.UTF_8.name());
        return writer.toString();
    }

}