AbstractPDFOutput


1   package dinamica;
2   
3   import javax.servlet.*;
4   import javax.servlet.http.Cookie  ;
5   import java.io.BufferedInputStream  ;
6   import java.io.ByteArrayOutputStream  ;
7   import java.net.HttpURLConnection  ;
8   import java.net.URL  ;
9   import com.lowagie.text.*;
10  import com.lowagie.text.pdf.*;
11  
12  /**
13   * Base class to produce PDF output modules (hand made reports)
14   * based on the powerful IText-PDF open source component.<br>
15   * This super class provides several common utility methods, including
16   * the abiity to auto-read the report header, footer and title from web.xml
17   * or config.xml, and to retrieve images from URLs (local or remotes), which is
18   * used to insert charts into the PDF document by reusing a server-side chart Action, 
19   * or to insert another dinamically generated image, like a BarCode. The method to retrieve
20   * via HTTP is session sensitive, meaning that it can reuse the same session ID, which is
21   * a requirement when accessing local resources that are session-sensitive, like chart Actions.
22   * <br><br>
23   * In order to reuse this class, you must override the method createPDF(), you may use
24   * the default implementation as a code template. For more information look into
25   * the /source and /templates resources included with Dinamica distribution.
26   * <br><br>
27   * (c) 2004 Martin Cordova<br>
28   * This code is released under the LGPL license<br>
29   * Dinamica Framework - http://www.martincordova.com
30   * @author Martin Cordova (dinamica@martincordova.com)
31   * */
32  public class AbstractPDFOutput extends GenericOutput
33  {
34  
35      /* (non-Javadoc)
36       * @see dinamica.GenericOutput#print(dinamica.GenericTransaction)
37       */
38      public void print(GenericTransaction data) throws Throwable  
39      {
40          ByteArrayOutputStream   buf = new ByteArrayOutputStream  ();
41          createPDF(data, buf);
42          getResponse().setContentLength(buf.size());
43          ServletOutputStream out = getResponse().getOutputStream();
44          buf.writeTo(out);
45          out.close();
46      }
47  
48      protected void createPDF(GenericTransaction data, ByteArrayOutputStream   buf) throws Throwable  
49      {
50  
51          //pdf objects
52          Document doc = new Document();
53          PdfWriter docWriter = PdfWriter.getInstance(doc, buf);
54  
55          //header
56          HeaderFooter header = new HeaderFooter(new Phrase(getHeader()), false);
57          header.setBorder(Rectangle.BOTTOM);
58          header.setAlignment(Rectangle.ALIGN_CENTER);
59          doc.setHeader(header);
60              
61          //footer
62          HeaderFooter footer = new HeaderFooter(new Phrase(getFooter()), true);
63          footer.setBorder(Rectangle.TOP);
64          footer.setAlignment(Rectangle.ALIGN_RIGHT);
65          doc.setFooter(footer);
66              
67          //pagesize
68          doc.setPageSize(PageSize.LETTER);
69  
70          doc.open();
71              
72              //title
73              Paragraph t = new Paragraph(getReportTitle(),new Font(Font.HELVETICA, 18f));
74              t.setAlignment(Rectangle.ALIGN_CENTER);
75              doc.add(t);
76              
77              //paragraph
78              Paragraph p = new Paragraph("Hello World");
79              p.setAlignment(Rectangle.ALIGN_CENTER);
80              doc.add(p);
81              
82          doc.close();
83          docWriter.close();
84          
85      }
86  
87      /**
88       * Get default report header (parameter pdf-header) from web.xml (context-param) or current config.xml (custom element).
89       * Any subclass may override this method.
90       * @return Report header text or NULL
91       */
92      protected String   getHeader()
93      {
94          
95          return getPDFConfigValue("pdf-header");
96  
97      }
98      
99      /**
100      * Get default report footer (parameter pdf-footer) from web.xml (context-param) or current config.xml (custom element).
101      * Any subclass may override this method.
102      * @return Report footer text or NULL
103      */
104     protected String   getFooter()
105     {
106         return getPDFConfigValue("pdf-footer") + " ";
107     }
108 
109     /**
110      * Get default report title (parameter pdf-title) from web.xml (context-param) or current config.xml (custom element).
111      * Most of the time the report title should be defined in config.xml because it is
112      * specific to the report.
113      * Any subclass may override this method.
114      * @return Report title text or NULL
115      */
116     protected String   getReportTitle()
117     {
118         return getPDFConfigValue("pdf-title");
119     }
120 
121     /**
122      * Read a PDF-related config parameter. Will search first
123      * in the Action config.xml, then in web.xml file.
124      * @param param
125      * @return The corresponding value or NULL if not found.
126      */
127     protected String   getPDFConfigValue(String   param)
128     {
129         String   value = null;
130         try
131         {
132             value = getConfig().getConfigValue(param);
133             if (value==null || value.trim().equals(""))
134             {
135                 value = getContext().getInitParameter(param);
136             }
137         }
138         catch (Throwable   e)
139         {
140             value = getContext().getInitParameter(param);
141             if (value==null)
142                 value = "";
143         }
144         return value;
145     }
146 
147     /**
148      * Return byte array with the content of a remote binary resource
149      * accessed via HTTP(S).
150      * @param url URL of the resource
151      * @param sessionID Session ID
152      * @param logStdout If TRUE will print trace log to System.out.
153      * @return Byte array with the content of the file
154      * @throws Throwable In case of any HTTP error of if the data cannot
155      * be read for any reason.
156      */
157     protected byte[] getImage(String   url, String   sessionID, boolean logStdout) throws Throwable  
158     {
159 
160         HttpURLConnection   urlc = null;
161         BufferedInputStream   bin = null;
162         final int bufferSize = 10240;
163         byte[] buffer = null;
164         URL   page = new URL  (url); 
165         ByteArrayOutputStream   bout = new ByteArrayOutputStream  ();
166             
167         if (logStdout)
168             System.err.println("Waiting for reply...:" + url);
169 
170         try
171         {
172             urlc = (HttpURLConnection  )page.openConnection();          
173             urlc.setUseCaches(false);
174             urlc.addRequestProperty("Cookie", "JSESSIONID=" + sessionID);
175             
176             if (logStdout)
177             {
178                 System.err.println("Content-type = " + urlc.getContentType()); 
179                 System.err.println("Content-length = " + urlc.getContentLength()); 
180                 System.err.println("Response-code = " + urlc.getResponseCode());
181                 System.err.println("Response-message = " + urlc.getResponseMessage());
182             }
183             
184             int retCode = urlc.getResponseCode();
185             String   retMsg = urlc.getResponseMessage();
186             if (retCode>=400)
187                 throw new Throwable  ("HTTP Error: " + retCode + " - " + retMsg + " - URL:" + url);
188                             
189             int size = urlc.getContentLength();
190             if (size > 0)               
191                 buffer = new byte[size];
192             else
193                 buffer = new byte[bufferSize];
194             
195             bin = new BufferedInputStream  (urlc.getInputStream(), buffer.length);
196                                                
197             int bytesRead = 0;
198             do
199             {
200                 bytesRead = bin.read(buffer);
201                 if (bytesRead > 0)
202                     bout.write(buffer, 0, bytesRead);
203             } while (bytesRead != -1);
204             
205             if (logStdout)
206             {
207                 System.err.println("Connection closed.");
208             }
209             
210             return bout.toByteArray();
211             
212         }
213         catch (Throwable   e)
214         {
215             throw e;
216         }
217         finally
218         {
219             if (bin != null)
220                 bin.close();
221                 
222             if (urlc != null)
223                 urlc.disconnect();
224         }
225 
226     }
227 
228     /**
229      * Retrieve the session ID from the request headers
230      * looking for a cookie named JSESSIONID. This method was
231      * implemented because some Servers (WepSphere 5.1) won't
232      * return the real cookie value when the HttpSession.getId()
233      * method is invoked, which causes big trouble when retrieving an
234      * image from an Action using HTTP and the session ID. This problem
235      * was discovered while testing PDF reports with charts on WAS 5.1, it
236      * is specific to WAS 5.1, but this method works well with all tested
237      * servlet engines, including Resin 2.x. 
238      * @return The session ID as stored in the cookie header, or NULL if it can find the cookie.
239      * @throws Throwable
240      */
241     protected String   getSessionID()
242     {
243         String   value = null;
244         Cookie   c[] = getRequest().getCookies();
245         for (int i=0;i<c.length;i++)
246         {
247             if (c[i].getName().equals("JSESSIONID"))
248             {
249                 value = c[i].getValue();
250                 break;
251             }
252         }
253         return value;
254     }
255 
256     /**
257      * Return byte array with the content of a remote binary resource
258      * accessed via HTTP(S) - a Cookie header (JSESSIONID) with the current
259      * session ID will be added to the request headers
260      * @param url URL of the resource
261      * @param logStdout If TRUE will print trace log to System.err.
262      * @return Byte array with the content of the file
263      * @throws Throwable In case of any HTTP error of if the data cannot
264      * be read for any reason.
265      */
266     protected byte[] getImage(String   url, boolean logStdout) throws Throwable  
267     {
268         String   sID = getSessionID();
269         return getImage(url, sID, logStdout);
270     }   
271 
272 }
273
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