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1
22
23 package de.laures.cewolf;
24
25 import java.io.IOException  ;
26 import java.io.OutputStream ;
27 import java.io.Writer ;
28 import java.util.Enumeration ;
29
30 import javax.servlet.ServletConfig ;
31 import javax.servlet.ServletException ;
32 import javax.servlet.http.HttpServlet ;
33 import javax.servlet.http.HttpServletRequest ;
34 import javax.servlet.http.HttpServletResponse ;
35
36 import de.laures.cewolf.util.RenderingHelper;
37
38
53 public class CewolfRenderer extends HttpServlet implements WebConstants
54 {
55
56 public static final String INIT_CONFIG = "CewolfRenderer_Init_Config";
57 private static final String STATE = "state";
58 private boolean debugged = false;
59 private int requestCount = 0;
60 private Byte lock = Byte.valueOf("0");
61 private Configuration config = null;
62
63 public void init( ServletConfig servletCfg ) throws ServletException
64 {
65 super.init(servletCfg);
66
67 servletCfg.getServletContext().setAttribute(INIT_CONFIG, servletCfg);
69 config = Configuration.getInstance(servletCfg.getServletContext());
70
71 if (config != null)
72 this.debugged = config.isDebugged();
73 else
74 this.debugged = false;
75 }
76
77
89
90 public void printParameters(HttpServletRequest request)
91 {
92 Enumeration enumeration = request.getParameterNames();
93 while (enumeration.hasMoreElements())
94 {
95 String cur = (String )enumeration.nextElement();
96 Object obj = request.getParameter(cur);
97
98 log("Request Parameter -> " + cur + " Value -> " + obj.toString());
99 }
100 }
101
102 protected void doGet( HttpServletRequest request, HttpServletResponse response ) throws ServletException , IOException
103 {
104 if ( debugged )
105 {
106 logRequest(request);
107 }
108 addHeaders(response);
109 if ( request.getParameter(STATE) != null || !request.getParameterNames().hasMoreElements() )
110 {
111 requestState(response);
112 return;
113 }
114 synchronized (lock) {
115 requestCount++;
116 }
117
118 int width = 400;
119 int height = 400;
120 boolean removeAfterRendering = false;
121 if ( request.getParameter(REMOVE_AFTER_RENDERING) != null )
122 {
123 removeAfterRendering = true;
124 }
125 if ( request.getParameter(WIDTH_PARAM) != null )
126 {
127 width = Integer.parseInt(request.getParameter(WIDTH_PARAM));
128 }
129 if ( request.getParameter(HEIGHT_PARAM) != null )
130 {
131 height = Integer.parseInt(request.getParameter(HEIGHT_PARAM));
132 }
133
134 String imgKey = request.getParameter(IMG_PARAM);
136 if ( imgKey == null )
137 {
138 logAndRenderException(new ServletException ("no '" + IMG_PARAM + "' parameter provided for Cewolf servlet."), response, width, height);
139 return;
140 }
141 Storage storage = config.getStorage();
142 ChartImage chartImage = storage.getChartImage(imgKey, request);
143 if ( chartImage == null )
144 {
145 renderImageExpiry(response, width, height);
146 return;
147 }
148 try
150 {
151 long start = System.currentTimeMillis();
152 final int size = chartImage.getSize();
154 response.setContentType(chartImage.getMimeType());
155 response.setContentLength(size);
156 response.setBufferSize(size);
157 response.setStatus(HttpServletResponse.SC_OK);
158 response.getOutputStream().write(chartImage.getBytes());
159 long last = System.currentTimeMillis() - start;
160 if ( debugged )
161 {
162 log("creation time for chart " + imgKey + ": " + last + "ms.");
163 }
164 }
165 catch (Throwable t)
166 {
167 logAndRenderException(t, response, width, height);
168 }
169 finally
170 {
171 if (removeAfterRendering)
172 {
173 try {
174 storage.removeChartImage(imgKey , request);
175 } catch (CewolfException e) {
176 log("Removal of image failed", e);
177 }
178 }
179 }
180 }
181
182
187 private void addHeaders( HttpServletResponse response )
188 {
189 response.setDateHeader("Expires", System.currentTimeMillis());
190 }
191
192
198 private void requestState( HttpServletResponse response ) throws IOException
199 {
200 Writer writer = response.getWriter();
201 writer.write("<HTML><BODY>");
202
207 writer.write("<b>Cewolf servlet up and running.</b><br>");
208 writer.write("Requests served so far: " + requestCount);
209 writer.write("</HTML></BODY>");
210 writer.close();
211 }
212
213 private void logAndRenderException( Throwable ex, HttpServletResponse response, int width, int height ) throws IOException
214 {
215 log(ex.getMessage(), ex);
216 response.setContentType("image/jpg");
217 OutputStream out = response.getOutputStream();
218 RenderingHelper.renderException(ex, width, height, out);
219 out.close();
220 }
221
222
229 private void renderImageExpiry( HttpServletResponse response, int width, int height ) throws IOException
230 {
231 response.setContentType("image/jpg");
232 OutputStream out = response.getOutputStream();
233 RenderingHelper.renderMessage("This chart has expired. Please reload.", width, height, out);
234 out.close();
235 }
236
237 private void logRequest( HttpServletRequest request ) throws IOException
238 {
239 log("Cewolf request:");
240 log("Actual Request values:");
241 printParameters(request);
242 Enumeration headerNames = request.getHeaderNames();
243 while ( headerNames.hasMoreElements() )
244 {
245 String name = (String ) headerNames.nextElement();
246 Enumeration values = request.getHeaders(name);
247 StringBuffer value = new StringBuffer ();
248 while ( values.hasMoreElements() )
249 {
250 value.append((String ) values.nextElement() + ",");
251 }
252 if ( value.length() > 0 )
254 value.setLength(value.length() - 1);
255 log(name + ": " + value);
256 }
257
263 }
264
265 } |
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