pserveraccrinterface.java

这是一个用java和xml编写的流媒体服务器管理软件

  /**
   * Find out whether a particular group for a particular feature type has at
   * least one server associated with it.
   */
  public boolean hasServer(String featureType, String group) 
    throws IOException, SAXException, VPPNoSuchFileException
  {
    if (groupServers == null)
    {
      getFeatureInformation();
    }

    Boolean has = (Boolean) groupServers.get(featureType + group);

    if (has != null)
    {
      return true;
    }

    return false;
  }


  /**
   * Get the groups which are configured for the feature with the given name. <p>
   * The data comes from the SystemConfiguration_ListofFeatureServers file
   * on the pserver.
   */
  public String[] getFeatureGroups(String featureName) 
    throws IOException, SAXException, VPPNoSuchFileException
  {
    if (featureGroups == null)
    {
      getFeatureInformation();
    }

    Vector groups = (Vector) featureGroups.get(featureName);
    String[] groupNames = new String[groups.size()];

    for (int i = 0; i < groups.size(); i++)
    {
      groupNames[i] = (String) groups.elementAt(i);
    }

    return groupNames;
  }

  /**
   * Retrieves a list of the names of the features which are configured. <p>
   * The data comes from the SystemConfiguration_ListofFeatureServers file
   * on the pserver.
   */
  public String[] getFeatureTypes() 
    throws IOException, SAXException, VPPNoSuchFileException
  {
    if (featureGroups == null)
    {
      getFeatureInformation();
    }

    Set keys = featureGroups.keySet();
    String[] types = new String[keys.size()];
    Iterator iterator = keys.iterator();
    int i = 0;

    while (iterator.hasNext())
    {
      types[i] = (String) iterator.next();
      i++;
    }

    return types;
  }

  /**
   * Reads the SystemConfiguration_ListOfFeatureServers file from the pserver
   * to determine the feature types and the group names for each feature which
   * are configured on the pserver.
   */
  private void getFeatureInformation() 
    throws IOException, SAXException, VPPNoSuchFileException
  {
    featureGroups = new Hashtable();
    groupServers = new Hashtable();

    String filegroup = "SystemConfiguration";
    String filename = "ListOfFeatureServers";

    try
    {
      BufferedReader configInfo = connection.request("GET", filegroup, 
              filename);

      Document doc = parser.parse(new InputSource(configInfo));


      NodeList features = doc.getElementsByTagName("serverType");

      for (int i = 0; i < features.getLength(); i++)
      {

        // get the feature name
        String typeName = 
          features.item(i).getAttributes().getNamedItem("value").getNodeValue();

        // get a list of groups associated with that feature
        NodeList groups = 
          ((Element) features.item(i)).getElementsByTagName("serverGroup");
        Vector groupNames = new Vector();

        for (int j = 0; j < groups.getLength(); j++)
        {
          Element group = (Element) groups.item(j);
          String groupName = 
            group.getAttributes().getNamedItem("value").getNodeValue();

          if (groupName != null)
          {
            groupNames.addElement(groupName);

            // find out if this feature group has any servers associated with it
            if (group.hasChildNodes())
            {
              NodeList servers = 
                group.getElementsByTagName("server");   // get all server nodes

              if (servers.getLength() > 0)
              {
                String host = 
                  ((Element) servers.item(0)).getAttribute("host");

                if (host != null)
                {
                  groupServers.put(typeName + groupName, 
                                   new Boolean(true));  // key is featureType+groupName
                }       // end if host attribute is defined
              }         // end if there are server elements
            }           // end if group has child nodes
          }             // end if group has name

        }

        if (groupNames.size() > 0)
        {
          featureGroups.put(typeName, groupNames);
        }
      }
    }
    catch (VPPException ex)
    {
      if (VPPNoSuchFileException.class.isInstance(ex))
      {
        throw new VPPNoSuchFileException("Could not load file " + filegroup 
                + " " + filename + "\n\nbecause:\n\n" + ex.getMessage());
      }
      else
      {
        connection.showVPPException(ex, "");
      }
    }
  }                     // end method getFeatureGroups

  /**
   * Get the underlying VPPTransactionWrapper which is used by this class
   * to communicate with the pserver.
   */
  public VPPTransactionWrapper getConnection()
  {
    return connection;
  }     // end method getConnection

  public static String getMasterUserNameFromXml(String xml)
  {

    // this should be done using an xml parser ...
    int index = xml.indexOf("masterUser=\"") + "masterUser=\"".length();
    String masterName = xml.substring(index, xml.indexOf("\"", index + 1));

    return masterName;
  }

  /**
   * Takes the given xml string and extracts the value of the password element.
   * Returns null if the element is not present.
   */
  public String getPasswordFromXml(String xml)
  {
    SAXParserFactory spf = SAXParserFactory.newInstance();
    SAXParser parser = null;
    try
    {
      parser = spf.newSAXParser();
    }
    catch (ParserConfigurationException e1)
    {
      e1.printStackTrace();
      return "";
    }
    catch (SAXException e2)
    {
      e2.printStackTrace();
      return "";
    }
    PasswordHandler handler = new PasswordHandler();

    try
    {
      parser.parse(new InputSource(new StringReader(xml)), handler);

      return handler.getPassword();
    }
    catch (Exception e)
    {

      // quietly suppress this exception
      e.printStackTrace();
    }

    return null;
  }


  /**
   * A content handler for the sax parser used to retrieve the password element
   * from the file. Note that the password is returned in its raw (hashed)
   * form.
   */
  class PasswordHandler extends DefaultHandler
  {
    private boolean atPasswordElement = false;
    private String password = null;

    public void startElement(String ignore1, String ignore2, String rawName, 
            Attributes attr)
    {
      if (rawName.equals("password"))
      {
        atPasswordElement = true;
      }
    }

    public void characters(char[] ch, int start, int length)
    {
      if (atPasswordElement)
      {
        password = new String(ch, start, length);
      }
    }

    public void endElement(java.lang.String uri, java.lang.String localName, 
            java.lang.String rawName)
    {
      if (rawName.equals("password"))
      {
        atPasswordElement = false;
      }
    }

    public String getPassword()
    {
      return password;
    }

  }     // end inner class PasswordHandler


  /**
   * Check whenter the supplied xml string allows access level of the supplied
   * type (ie: admin or tech).
   * This parses the file, finds the "accessLevel" elements (returns false if
   * they do not exist), matches the "type" attribute to the supplied type and
   * then returns the value of the "enabled" attribute.
   */
  public boolean allowsAccessOfType(String xml, 
          String type) throws IOException, SAXException
  {
    Document doc = parser.parse(new InputSource(new StringReader(xml)));

    NodeList accessLevels = doc.getElementsByTagName("accessLevel");

    if (accessLevels == null)
    {
      return false;
    }

    if (accessLevels.getLength() < 1)
    {
      return false;
    }

    for (int i = 0; i < accessLevels.getLength(); i++)
    {
      Element accessLevel = (Element) accessLevels.item(i);
      String typeFromFile = accessLevel.getAttribute("type");

      if (typeFromFile.equals(type))
      {
        String enabled = accessLevel.getAttribute("enabled");

        if (enabled.equals("true"))
        {
          return true;
        }
        else
        {
          return false;
        }
      }
    }

    return false;
  }

  /**
   * @return true if the alias file was successfully created and saved, false
   * otherwise.
   */
  public boolean saveAlias(String aliasName, String masterName)
  {

    // want aliases to be unique, so check whether there is a user with the
    // same name as the proposed alias
    try
    {
      connection.doGet("Accounts", aliasName);
    }
    catch (VPPException exx)
    {
      if (VPPNoSuchFileException.class.isInstance(exx))
      {

        // this user name does not exist -> ok
        // now check whether this alias already exists
        String response = "";

        try
        {
          response = connection.doGet("Aliases", aliasName);
        }
        catch (VPPException ex)
        {
          if (VPPNoSuchFileException.class.isInstance(ex))
          {

            // there is not a user with this name either
            // so its ok to create the alias
            String xml = "<userAlias masterUser=\"" + masterName 
                         + "\" alias=\"" + aliasName + "\"></userAlias>";

            try
            {
              connection.doPut("Aliases", aliasName, xml);
            }
            catch (VPPException e)
            {
              connection.showVPPException(e, "");
            }

            return true;
          }     // end if no such user
          else
          {
            connection.showVPPException(ex, "");
          }
        }

        // if the alias exists, that is not necessarily and error: it may belong
        // to this user
        if (response.indexOf(masterName) != -1)

        // if the user name is contained anywhere in the alias file, then assume
        // that this alias belongs to this user. This should probably be done
        // by actually parsing the file, but for now its good enough.
        {
          return true;
        }
      }         // end if no such alias
      else
      {
        connection.showVPPException(exx, "");
      }
    }

    return false;
  }


  public void deleteAliasFile(String alias) throws VPPNoSuchFileException
  {
    try
    {
      connection.request("REMOVE", "Aliases", alias);
    }
    catch (VPPException ex)
    {
      if (VPPNoSuchFileException.class.isInstance(ex))
      {
        throw (VPPNoSuchFileException) ex;
      }
      else
      {
        connection.showVPPException(ex, "");
      }
    }
  }

}       // end class PServerInterface