com.highway2urhell.VersionUtils Maven / Gradle / Ivy

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package com.highway2urhell;

import java.io.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.Properties;
import java.util.jar.Attributes;
import java.util.jar.Manifest;

public class VersionUtils {

	public static final String UNKNOWN_VERSION = "UNKNOWN";
	public static final String NO_FRAMEWORK = "NO_FRAMEWORK";

	private VersionUtils() {
	}

	public static String getVersion(String clazzName, String groupId,
			String artifactId) {
		//check 
		Class clazz;
		try {
			clazz = Class.forName(clazzName);
		} catch (ClassNotFoundException e1) {
			return NO_FRAMEWORK;
		}
		String version = null;
		
		// try to load from maven properties first
		Properties p = new Properties();
		InputStream is = null;

		try {
			is = clazz.getResourceAsStream("/META-INF/maven/" + groupId + "/"
					+ artifactId + "/pom.properties");
			if (is != null) {
				p.load(is);
				version = p.getProperty("version", "");
			}
		} catch (Exception e) {
			// ignore
		} finally {
			if (is != null) {
				try {
					is.close();
				} catch (IOException e) {
					// ignore
				}
			}
		}

		// try to load from manifest
		try {
			URL clazzRes = clazz.getResource('/' + clazz.getName().replace('.', '/') + ".class");
			String classResPath = clazzRes.getPath();
			Manifest manifest = null;
			if (classResPath.contains("!")) {
				classResPath = classResPath.split("!")[0];
				URL url = new URL("jar:" + classResPath + "!/");
				JarURLConnection jarConnection = (JarURLConnection) url.openConnection();
				manifest = jarConnection.getManifest();
			} else {
				is = clazz.getResourceAsStream(classResPath + "!/META-INF/MANIFEST.MF");
				if (is != null)
					manifest = new Manifest(is);

			}
			if (manifest != null)
			{
				Attributes attr = manifest.getMainAttributes();
				version = attr.getValue("Implementation-Version");
			}
		} catch (Exception e) {
			// ignore
		} finally {
			if (is != null) {
				try {
					is.close();
				} catch (IOException e) {
					// ignore
				}
			}
		}



		// fallback to using Java API
		if (version == null) {
			Package aPackage = clazz.getPackage();
			if (aPackage != null) {
				version = aPackage.getImplementationVersion();
				if (version == null) {
					version = aPackage.getSpecificationVersion();
				}
			}
		}
		if (version == null) {
			// we could not compute the version so use a blank
			version = UNKNOWN_VERSION;
		}

		return version;
	}

}