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1
29
30 package com.caucho.servlets;
31
32 import com.caucho.util.L10N;
33 import com.caucho.vfs.Path;
34 import com.caucho.vfs.ReadStream;
35 import com.caucho.vfs.ReadWritePair;
36 import com.caucho.vfs.Vfs;
37 import com.caucho.vfs.WriteStream;
38
39 import javax.servlet.GenericServlet  ;
40 import javax.servlet.ServletException ;
41 import javax.servlet.ServletRequest ;
42 import javax.servlet.ServletResponse ;
43 import javax.servlet.http.HttpServletRequest ;
44 import javax.servlet.http.HttpServletResponse ;
45 import java.io.IOException ;
46 import java.io.InputStream ;
47 import java.io.OutputStream ;
48 import java.io.PrintWriter ;
49 import java.util.ArrayList ;
50 import java.util.Enumeration ;
51 import java.util.Iterator ;
52 import java.util.logging.Level ;
53 import java.util.logging.Logger ;
54
55
66 public class HttpProxyServlet extends GenericServlet {
67 static protected final Logger log =
68 Logger.getLogger(HttpProxyServlet.class.getName());
69 static final L10N L = new L10N(HttpProxyServlet.class);
70
71 private ArrayList <String > _hosts = new ArrayList <String >();
72 private Path []_urlPaths;
73 private int _roundRobin;
74
75
78 public void addHost(String host)
79 {
80 _hosts.add(host);
81 }
82
83
86 public void init()
87 throws ServletException
88 {
89 if (_hosts.size() == 0)
90 throw new ServletException (L.l("HttpProxyServlet needs at least one host."));
91
92 _urlPaths = new Path[_hosts.size()];
93
94 for (int i = 0; i < _hosts.size(); i++) {
95 String host = _hosts.get(i);
96
97 if (host.startsWith("http"))
98 _urlPaths[i] = Vfs.lookup(host);
99 else
100 _urlPaths[i] = Vfs.lookup("http://" + host);
101 }
102 }
103
104
107 public void service(ServletRequest request, ServletResponse response)
108 throws ServletException , IOException
109 {
110 HttpServletRequest req = (HttpServletRequest ) request;
111 HttpServletResponse res = (HttpServletResponse ) response;
112
113 PrintWriter out = res.getWriter();
114
115 int startIndex = _roundRobin;
116 _roundRobin = (_roundRobin + 1) % _urlPaths.length;
117
118 for (int i = 0; i < _urlPaths.length; i++) {
119 int index = (startIndex + i) % _urlPaths.length;
120
121 if (handleRequest(req, res, _urlPaths[index]))
122 return;
123 }
124
125 res.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
126 }
127
128 private boolean handleRequest(HttpServletRequest req,
129 HttpServletResponse res,
130 Path path)
131 throws ServletException , IOException
132 {
133 String hostURL = path.getURL();
134
135 String uri;
136 if (req.isRequestedSessionIdFromUrl()) {
137 uri = (req.getRequestURI() + ";jsessionid=" +
138 req.getRequestedSessionId());
139 }
140 else
141 uri = req.getRequestURI();
142
143 if (req.getQueryString() != null)
144 uri += '?' + req.getQueryString();
145
146 path = path.lookup(uri);
147
148 ReadWritePair pair = path.openReadWrite();
149
150 ReadStream rs = pair.getReadStream();
151 WriteStream ws = pair.getWriteStream();
152
153 ws.setAttribute("method", req.getMethod());
154
155 Enumeration e = req.getHeaderNames();
156 while (e.hasMoreElements()) {
157 String name = (String ) e.nextElement();
158 String value = req.getHeader(name);
159
160 ws.setAttribute(name, value);
161 }
162
163 try {
164 InputStream is = req.getInputStream();
165 ws.writeStream(is);
166
167 String status = (String ) rs.getAttribute("status");
168 int statusCode = 200;
169
170 if (status != null) {
171 try {
172 statusCode = Integer.parseInt(status);
173 } catch (Throwable e1) {
174 }
175 }
176
177 String location = null;
178 Iterator iter = rs.getAttributeNames();
179 while (iter.hasNext()) {
180 String name = (String ) iter.next();
181
182 if (name.equalsIgnoreCase("status")) {
183 }
184 else if (name.equalsIgnoreCase("transfer-encoding")) {
185 }
186 else if (name.equalsIgnoreCase("content-length")) {
187 }
188 else if (name.equalsIgnoreCase("location"))
189 location = (String ) rs.getAttribute("location");
190 else
191 res.addHeader(name, (String ) rs.getAttribute(name));
192 }
193
194 if (location == null) {
195 }
196 else if (location.startsWith(hostURL)) {
197 location = location.substring(hostURL.length());
198
199 String prefix;
200 if (req.isSecure()) {
201 if (req.getServerPort() != 443)
202 prefix = ("https://" + req.getServerName() +
203 ":" + req.getServerPort());
204 else
205 prefix = ("https://" + req.getServerName());
206 }
207 else {
208 if (req.getServerPort() != 80)
209 prefix = ("http://" + req.getServerName() +
210 ":" + req.getServerPort());
211 else
212 prefix = ("http://" + req.getServerName());
213 }
214
215 if (! location.startsWith("/"))
216 location = prefix + "/" + location;
217 else
218 location = prefix + location;
219 }
220
221 if (location != null)
222 res.setHeader("Location", location);
223
224 if (statusCode == 302 && location != null)
225 res.sendRedirect(location);
226 else if (statusCode != 200)
227 res.setStatus(statusCode);
228
229 OutputStream os = res.getOutputStream();
230 rs.writeToStream(os);
231 } catch (IOException e1) {
232 log.log(Level.FINE, e1.toString(), e1);
233
234 return false;
235 } finally {
236 ws.close();
237 rs.close();
238 }
239
240 return true;
241 }
242 }
243 |
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