MetaServlet.java

  1. /*
  2.  * Copyright (C) 2009-2010, Google Inc. and others
  3.  *
  4.  * This program and the accompanying materials are made available under the
  5.  * terms of the Eclipse Distribution License v. 1.0 which is available at
  6.  * https://www.eclipse.org/org/documents/edl-v10.php.
  7.  *
  8.  * SPDX-License-Identifier: BSD-3-Clause
  9.  */

  10. package org.eclipse.jgit.http.server.glue;

  11. import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;

  12. import java.io.IOException;

  13. import javax.servlet.ServletConfig;
  14. import javax.servlet.ServletContext;
  15. import javax.servlet.ServletException;
  16. import javax.servlet.ServletRequest;
  17. import javax.servlet.ServletResponse;
  18. import javax.servlet.http.HttpServlet;
  19. import javax.servlet.http.HttpServletRequest;
  20. import javax.servlet.http.HttpServletResponse;

  21. /**
  22.  * Generic container servlet to manage routing to different pipelines.
  23.  * <p>
  24.  * Callers can create and configure a new processing pipeline by using one of
  25.  * the {@link #serve(String)} or {@link #serveRegex(String)} methods to allocate
  26.  * a binder for a particular URL pattern.
  27.  * <p>
  28.  * Registered filters and servlets are initialized lazily, usually during the
  29.  * first request. Once initialized the bindings in this servlet cannot be
  30.  * modified without destroying the servlet and thereby destroying all registered
  31.  * filters and servlets.
  32.  */
  33. public class MetaServlet extends HttpServlet {
  34.     private static final long serialVersionUID = 1L;

  35.     private final MetaFilter filter;

  36.     /**
  37.      * Empty servlet with no bindings.
  38.      */
  39.     public MetaServlet() {
  40.         this(new MetaFilter());
  41.     }

  42.     /**
  43.      * Initialize a servlet wrapping a filter.
  44.      *
  45.      * @param delegateFilter
  46.      *            the filter being wrapped by the servlet.
  47.      */
  48.     protected MetaServlet(MetaFilter delegateFilter) {
  49.         filter = delegateFilter;
  50.     }

  51.     /**
  52.      * Get delegate filter
  53.      *
  54.      * @return filter this servlet delegates all routing logic to.
  55.      */
  56.     protected MetaFilter getDelegateFilter() {
  57.         return filter;
  58.     }

  59.     /**
  60.      * Construct a binding for a specific path.
  61.      *
  62.      * @param path
  63.      *            pattern to match.
  64.      * @return binder for the passed path.
  65.      */
  66.     public ServletBinder serve(String path) {
  67.         return filter.serve(path);
  68.     }

  69.     /**
  70.      * Construct a binding for a regular expression.
  71.      *
  72.      * @param expression
  73.      *            the regular expression to pattern match the URL against.
  74.      * @return binder for the passed expression.
  75.      */
  76.     public ServletBinder serveRegex(String expression) {
  77.         return filter.serveRegex(expression);
  78.     }

  79.     /** {@inheritDoc} */
  80.     @Override
  81.     public void init(ServletConfig config) throws ServletException {
  82.         String name = filter.getClass().getName();
  83.         ServletContext ctx = config.getServletContext();
  84.         filter.init(new NoParameterFilterConfig(name, ctx));
  85.     }

  86.     /** {@inheritDoc} */
  87.     @Override
  88.     public void destroy() {
  89.         filter.destroy();
  90.     }

  91.     /** {@inheritDoc} */
  92.     @Override
  93.     protected void service(HttpServletRequest req, HttpServletResponse res)
  94.             throws ServletException, IOException {
  95.         filter.doFilter(req, res,
  96.                 (ServletRequest request, ServletResponse response) -> {
  97.                     ((HttpServletResponse) response).sendError(SC_NOT_FOUND);
  98.                 });
  99.     }

  100.     /**
  101.      * Configure a newly created binder.
  102.      *
  103.      * @param b
  104.      *            the newly created binder.
  105.      * @return binder for the caller, potentially after adding one or more
  106.      *         filters into the pipeline.
  107.      */
  108.     protected ServletBinder register(ServletBinder b) {
  109.         return filter.register(b);
  110.     }
  111. }