protected JavaeeServerVersionDescriptor getVersionDescriptor(String home) throws Exception {
    File catalinaJar = new File(home, "lib/catalina.jar");
    boolean isServerLib = false;
    if (!catalinaJar.exists()) {
      catalinaJar = new File(home, "server/lib/catalina.jar");
      isServerLib = true;
      if (!catalinaJar.exists()) {
        throw new IOException("Can't find catalina.jar");
      }
    }

    String version;
    try {
      String versionProperty = VersionUtil.readJarProperty(catalinaJar, "org/apache/catalina/util/ServerInfo.properties", "server.info");
      version = StringUtil.trimStart(versionProperty, "Apache Tomcat/");
    }
    catch (IOException e) {
      if (!isServerLib) {
        throw e;
      }
      version = "4.0.x";
    }
    return new JavaeeServerVersionDescriptor(version, catalinaJar);
  }