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 void setName(String name);
51 public String getName();
53 public void processEndpoint(HttpServletRequest request,
54 HttpServletResponse response);
57 public interface Endpoint
59 public void processEndpoint(String endpointName,
60 HttpServletRequest request, HttpServletResponse response);
63 private static final String MY_PATH = "rest";
65 private static final String MY_NAME = "Rest";
67 private String missingEndpointMessage = null;
69 private boolean init = false;
71 // map of method names and method handlers
72 private Map<String, Endpoint> endpoints = null;
75 * Singleton instance of this class
77 private static RestHandler instance = null;
80 * Returns the singleton instance of this class
83 * @throws BindException
85 public static RestHandler getInstance() throws BindException
87 synchronized (RestHandler.class)
91 instance = new RestHandler();
98 * Private constructor enforces use of singleton
100 * @throws BindException
102 protected RestHandler() throws BindException
107 * We don't register the handler here - this is done as a special case in
108 * HttpServer initialisation; to do it here would invite an infinite loop of
109 * RestHandler/HttpServer constructor
114 * Handle a jalview/rest request
116 * @throws IOException
119 protected void processRequest(HttpServletRequest request,
120 HttpServletResponse response) throws IOException
123 * Currently just echoes the request; add helper classes as required to
126 System.out.println(request.toString());
127 if (endpoints == null)
129 final String queryString = request.getQueryString();
130 final String reply = "REST not yet implemented; received "
131 + request.getMethod() + ": " + request.getRequestURL()
132 + (queryString == null ? "" : "?" + queryString);
133 System.out.println(reply);
135 response.setHeader("Cache-Control", "no-cache/no-store");
136 response.setHeader("Content-type", "text/plain");
137 final PrintWriter writer = response.getWriter();
143 String endpointName = getEndpointName(request);
145 if (!endpoints.containsKey(endpointName)
146 || endpoints.get(endpointName) == null)
149 response.setHeader("Cache-Control", "no-cache/no-store");
150 response.setHeader("Content-type", "text/plain");
151 response.setStatus(400);
152 PrintWriter writer = response.getWriter();
153 writer.write(missingEndpointMessage == null
154 ? "REST endpoint '" + endpointName + "' not defined"
155 : missingEndpointMessage);
160 response.setHeader("Cache-Control", "no-cache/no-store");
161 response.setHeader("Content-type", "text/plain");
162 Endpoint ep = endpoints.get(endpointName);
163 ep.processEndpoint(endpointName, request, response);
169 * Returns a display name for this service
172 public String getName()
180 * @throws BindException
182 protected void init() throws BindException
187 protected void init(String path) throws BindException
190 // Override this in extended class
191 // e.g. registerHandler and addEndpoints
194 protected boolean addEndpoint(String name, Endpoint ep)
196 if (endpoints == null)
198 endpoints = new HashMap<>();
200 endpoints.put(name, ep);
204 protected String getEndpointName(HttpServletRequest request)
206 String pathInfo = request.getPathInfo();
207 int slashpos = pathInfo.indexOf('/', 1);
208 return slashpos > 1 ? pathInfo.substring(1, slashpos)
209 : pathInfo.substring(1);
212 protected String[] getEndpointPathParameters(HttpServletRequest request)
214 String pathInfo = request.getPathInfo();
215 int slashpos = pathInfo.indexOf('/', 1);
216 return slashpos < 1 ? null
217 : pathInfo.substring(slashpos + 1).split("/");
220 protected void returnError(HttpServletRequest request,
221 HttpServletResponse response, String message)
223 response.setStatus(500); // set this to something better
224 String endpointName = getEndpointName(request);
225 Cache.error(this.MY_NAME + " error: endpoint " + endpointName
226 + " failed: '" + message + "'");
229 PrintWriter writer = response.getWriter();
230 writer.write("Endpoint " + endpointName + ": " + message);
232 } catch (IOException e)
238 protected void returnStatus(HttpServletResponse response, String id,
243 PrintWriter writer = response.getWriter();
245 writer.write("id=" + id + "\n");
247 writer.write("status=" + status.toString() + "\n");
248 } catch (IOException e)
254 protected String getRequestBody(HttpServletRequest request)
257 StringBuilder sb = new StringBuilder();
258 BufferedReader reader = request.getReader();
262 while ((line = reader.readLine()) != null)
264 sb.append(line).append('\n');
270 return sb.toString();