Class HostManagerServlet

java.lang.Object
jakarta.servlet.GenericServlet
jakarta.servlet.http.HttpServlet
org.apache.catalina.manager.host.HostManagerServlet
All Implemented Interfaces:
Servlet, ServletConfig, Serializable, ContainerServlet
Direct Known Subclasses:
HTMLHostManagerServlet
public class HostManagerServlet extends HttpServlet implements ContainerServlet
Servlet that enables remote management of the virtual hosts installed on the server. Normally, this functionality will be protected by a security constraint in the web application deployment descriptor. However, this requirement can be relaxed during testing.

This servlet examines the value returned by getPathInfo() and related query parameters to determine what action is being requested. The following actions and parameters (starting after the servlet path) are supported:

  • /add?name={host-name}&aliases={host-aliases}&manager={manager} - Create and add a new virtual host. The host-name attribute indicates the name of the new host. The host-aliases attribute is a comma separated list of the host alias names. The manager attribute is a boolean value indicating if the webapp manager will be installed in the newly created host (optional, false by default).
  • /remove?name={host-name} - Remove a virtual host. The host-name attribute indicates the name of the host.
  • /list - List the virtual hosts installed on the server. Each host will be listed with the following format host-name#host-aliases.
  • /start?name={host-name} - Start the virtual host.
  • /stop?name={host-name} - Stop the virtual host.

NOTE - Attempting to stop or remove the host containing this servlet itself will not succeed. Therefore, this servlet should generally be deployed in a separate virtual host.

The following servlet initialization parameters are recognized:

  • debug - The debugging detail level that controls the amount of information that is logged by this servlet. Default is zero.
Author:
Craig R. McClanahan, Remy Maucherat
See Also:

  • Field Details

    • context

      protected transient Context context
      The Context container associated with our web application.

    • debug

      protected int debug
      The debugging detail level for this servlet.

    • installedHost

      protected transient Host installedHost
      The associated host.

    • engine

      protected transient Engine engine
      The associated engine.

    • sm

      protected static final StringManager sm
      The string manager for this package.

    • wrapper

      protected transient Wrapper wrapper
      The Wrapper container associated with this servlet.

  • Constructor Details

    • HostManagerServlet

      public HostManagerServlet()

  • Method Details

    • getWrapper

      public Wrapper getWrapper()
      Description copied from interface: ContainerServlet
      Obtain the Wrapper with which this Servlet is associated.
      Specified by:
      getWrapper in interface ContainerServlet
      Returns:
      The Wrapper with which this Servlet is associated.

    • setWrapper

      public void setWrapper(Wrapper wrapper)
      Description copied from interface: ContainerServlet
      Set the Wrapper with which this Servlet is associated.
      Specified by:
      setWrapper in interface ContainerServlet
      Parameters:
      wrapper - The new associated Wrapper

    • destroy

      public void destroy()
      Description copied from class: jakarta.servlet.GenericServlet
      Called by the servlet container to indicate to a servlet that the servlet is being taken out of service. See Servlet.destroy().
      Specified by:
      destroy in interface Servlet
      Overrides:
      destroy in class GenericServlet

    • doGet

      public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
      Description copied from class: jakarta.servlet.http.HttpServlet
      Called by the server (via the service method) to allow a servlet to handle a GET request.

      Overriding this method to support a GET request also automatically supports an HTTP HEAD request. A HEAD request is a GET request that returns no body in the response, only the request header fields.

      When overriding this method, read the request data, write the response headers, get the response's Writer or output stream object, and finally, write the response data. It's best to include content type and encoding. When using a PrintWriter object to return the response, set the content type before accessing the PrintWriter object.

      The servlet container must write the headers before committing the response, because in HTTP the headers must be sent before the response body.

      Where possible, set the Content-Length header (with the ServletResponse.setContentLength(int) method), to allow the servlet container to use a persistent connection to return its response to the client, improving performance. The content length is automatically set if the entire response fits inside the response buffer.

      When using HTTP 1.1 chunked encoding (which means that the response has a Transfer-Encoding header), do not set the Content-Length header.

      The GET method should be safe, that is, without any side effects for which users are held responsible. For example, most form queries have no side effects. If a client request is intended to change stored data, the request should use some other HTTP method.

      The GET method should also be idempotent, meaning that it can be safely repeated. Sometimes making a method safe also makes it idempotent. For example, repeating queries is both safe and idempotent, but buying a product online or modifying data is neither safe nor idempotent.

      If the request is incorrectly formatted, doGet returns an HTTP "Bad Request" message.

      Overrides:
      doGet in class HttpServlet
      Parameters:
      request - an HttpServletRequest object that contains the request the client has made of the servlet
      response - an HttpServletResponse object that contains the response the servlet sends to the client
      Throws:
      IOException - if an input or output error is detected when the servlet handles the GET request
      ServletException - if the request for the GET could not be handled
      See Also:

    • add

      protected void add(HttpServletRequest request, PrintWriter writer, String name, boolean htmlMode, StringManager smClient)
      Add host with the given parameters.
      Parameters:
      request - The request
      writer - The output writer
      name - The host name
      htmlMode - Flag value
      smClient - StringManager for the client's locale

    • booleanParameter

      protected boolean booleanParameter(HttpServletRequest request, String parameter, boolean theDefault, boolean htmlMode)
      Extract boolean value from checkbox with default.
      Parameters:
      request - The Servlet request
      parameter - The parameter name
      theDefault - Default value
      htmlMode - Flag value
      Returns:
      the boolean value for the parameter

    • init

      public void init() throws ServletException
      Description copied from class: jakarta.servlet.GenericServlet
      A convenience method which can be overridden so that there's no need to call super.init(config).

      Instead of overriding GenericServlet.init(ServletConfig), simply override this method and it will be called by GenericServlet.init(ServletConfig config). The ServletConfig object can still be retrieved via GenericServlet.getServletConfig().

      Overrides:
      init in class GenericServlet
      Throws:
      ServletException - if an exception occurs that interrupts the servlet's normal operation

    • add

      protected void add(PrintWriter writer, String name, String aliases, String appBase, boolean manager, boolean autoDeploy, boolean deployOnStartup, boolean deployXML, boolean unpackWARs, boolean copyXML, StringManager smClient)
      Add a host using the specified parameters.
      Parameters:
      writer - Writer to render results to
      name - host name
      aliases - comma separated alias list
      appBase - application base for the host
      manager - should the manager webapp be deployed to the new host ?
      autoDeploy - Flag value
      deployOnStartup - Flag value
      deployXML - Flag value
      unpackWARs - Flag value
      copyXML - Flag value
      smClient - StringManager for the client's locale

    • remove

      protected void remove(PrintWriter writer, String name, StringManager smClient)
      Remove the specified host.
      Parameters:
      writer - Writer to render results to
      name - host name
      smClient - StringManager for the client's locale

    • list

      protected void list(PrintWriter writer, StringManager smClient)
      Render a list of the currently active Contexts in our virtual host.
      Parameters:
      writer - Writer to render to
      smClient - StringManager for the client's locale

    • start

      protected void start(PrintWriter writer, String name, StringManager smClient)
      Start the host with the specified name.
      Parameters:
      writer - Writer to render to
      name - Host name
      smClient - StringManager for the client's locale

    • stop

      protected void stop(PrintWriter writer, String name, StringManager smClient)
      Stop the host with the specified name.
      Parameters:
      writer - Writer to render to
      name - Host name
      smClient - StringManager for the client's locale

    • persist

      protected void persist(PrintWriter writer, StringManager smClient)
      Persist the current configuration to server.xml.
      Parameters:
      writer - Writer to render to
      smClient - i18n resources localized for the client

    • getConfigBase

      protected File getConfigBase(String hostName)
      Get config base.
      Parameters:
      hostName - The host name
      Returns:
      the config base for the host