2 * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
3 * Copyright (C) $$Year-Rel$$ The Jalview Authors
5 * This file is part of Jalview.
7 * Jalview is free software: you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation, either version 3
10 * of the License, or (at your option) any later version.
12 * Jalview is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR
15 * PURPOSE. See the GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with Jalview. If not, see <http://www.gnu.org/licenses/>.
19 * The Jalview Authors are detailed in the 'AUTHORS' file.
23 import java.io.BufferedReader;
24 import java.io.IOException;
25 import java.io.PrintWriter;
26 import java.net.BindException;
27 import java.util.HashMap;
30 import javax.servlet.http.HttpServletRequest;
31 import javax.servlet.http.HttpServletResponse;
33 import jalview.bin.Cache;
34 import jalview.httpserver.AbstractRequestHandler;
37 * A simple handler to process (or delegate) HTTP requests on /jalview/rest
39 public class RestHandler extends AbstractRequestHandler
44 STARTED, IN_PROGRESS, FINISHED, ERROR
47 public interface EndpointI
49 public String getName();
51 public void processEndpoint(HttpServletRequest request,
52 HttpServletResponse response);
56 private static final String MY_PATH = "rest";
58 private static final String MY_NAME = "Rest";
60 private String missingEndpointMessage = null;
62 private boolean init = false;
64 // map of method names and method handlers
65 private Map<String, EndpointI> endpoints = null;
67 protected Map<String, EndpointI> getEndpoints()
73 * Singleton instance of this class
75 private static RestHandler instance = null;
78 * Returns the singleton instance of this class
81 * @throws BindException
83 public static RestHandler getInstance() throws BindException
85 synchronized (RestHandler.class)
89 instance = new RestHandler();
96 * Private constructor enforces use of singleton
98 * @throws BindException
100 protected RestHandler() throws BindException
105 * We don't register the handler here - this is done as a special case in
106 * HttpServer initialisation; to do it here would invite an infinite loop of
107 * RestHandler/HttpServer constructor
112 * Handle a jalview/rest request
114 * @throws IOException
117 protected void processRequest(HttpServletRequest request,
118 HttpServletResponse response) throws IOException
121 * Currently just echoes the request; add helper classes as required to
124 System.out.println(request.toString());
125 if (endpoints == null)
127 final String queryString = request.getQueryString();
128 final String reply = "REST not yet implemented; received "
129 + request.getMethod() + ": " + request.getRequestURL()
130 + (queryString == null ? "" : "?" + queryString);
131 System.out.println(reply);
133 response.setHeader("Cache-Control", "no-cache/no-store");
134 response.setHeader("Content-type", "text/plain");
135 final PrintWriter writer = response.getWriter();
141 String endpointName = getRequestedEndpointName(request);
143 if (!endpoints.containsKey(endpointName)
144 || endpoints.get(endpointName) == null)
147 response.setHeader("Cache-Control", "no-cache/no-store");
148 response.setHeader("Content-type", "text/plain");
149 response.setStatus(400);
150 PrintWriter writer = response.getWriter();
151 writer.write(missingEndpointMessage == null
152 ? "REST endpoint '" + endpointName + "' not defined"
153 : missingEndpointMessage);
158 response.setHeader("Cache-Control", "no-cache/no-store");
159 response.setHeader("Content-type", "text/plain");
160 EndpointI ep = endpoints.get(endpointName);
161 ep.processEndpoint(request, response);
167 * Returns a display name for this service
170 public String getName()
178 * @throws BindException
180 protected void init() throws BindException
185 protected void init(String path) throws BindException
188 // Override this in extended class
189 // e.g. registerHandler and addEndpoints
192 protected boolean addEndpoint(EndpointI ep)
194 if (endpoints == null)
196 endpoints = new HashMap<>();
198 Endpoint e = (Endpoint) ep;
199 endpoints.put(ep.getName(), ep);
203 protected String getRequestedEndpointName(HttpServletRequest request)
205 String pathInfo = request.getPathInfo();
206 int slashpos = pathInfo.indexOf('/', 1);
207 return slashpos > 1 ? pathInfo.substring(1, slashpos)
208 : pathInfo.substring(1);
211 protected String[] getEndpointPathParameters(HttpServletRequest request)
213 String pathInfo = request.getPathInfo();
214 int slashpos = pathInfo.indexOf('/', 1);
215 return slashpos < 1 ? null
216 : pathInfo.substring(slashpos + 1).split("/");
219 protected void returnError(HttpServletRequest request,
220 HttpServletResponse response, String message)
222 response.setStatus(500); // set this to something better
223 String endpointName = getRequestedEndpointName(request);
224 Cache.error(this.MY_NAME + " error: endpoint " + endpointName
225 + " failed: '" + message + "'");
228 PrintWriter writer = response.getWriter();
229 writer.write("Endpoint " + endpointName + ": " + message);
231 } catch (IOException e)
237 protected void returnStatus(HttpServletResponse response, String id,
242 PrintWriter writer = response.getWriter();
244 writer.write("id=" + id + "\n");
246 writer.write("status=" + status.toString() + "\n");
247 } catch (IOException e)
253 protected String getRequestBody(HttpServletRequest request)
256 StringBuilder sb = new StringBuilder();
257 BufferedReader reader = request.getReader();
261 while ((line = reader.readLine()) != null)
263 sb.append(line).append('\n');
269 return sb.toString();