URLTag


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3   * Part of the InfoGlue Content Management Platform (www.infoglue.org)
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10  * the terms of the GNU General Public License version 2, as published by the
11  * Free Software Foundation. See the file LICENSE.html for more information.
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14  * ANY WARRANTY, including the implied warranty of MERCHANTABILITY or FITNESS
15  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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18  * this program; if not, write to the Free Software Foundation, Inc. / 59 Temple
19  * Place, Suite 330 / Boston, MA 02111-1307 / USA.
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22  */
23  package org.infoglue.deliver.taglib.common;
24  
25  import java.util.ArrayList  ;
26  import java.util.HashMap  ;
27  import java.util.Iterator  ;
28  import java.util.List  ;
29  import java.util.Map  ;
30  import java.util.StringTokenizer  ;
31  
32  import javax.servlet.http.HttpServletRequest  ;
33  import javax.servlet.jsp.JspException  ;
34  import javax.servlet.jsp.JspTagException  ;
35  
36  import org.apache.log4j.Logger;
37  import org.infoglue.deliver.taglib.TemplateControllerTag;
38  
39  /**
40   * This class implements the &lt;common:urlBuilder&gt; tag, which creates an url
41   * from a base url (user supplied or taken from the request), 
42   * a query string (user supplied ot taken from the reuest) and
43   * any number of parameters specified using nested &lt;common:parameter&gt; tags.
44   */
45  public class URLTag extends TemplateControllerTag 
46  {
47  
48      private final static Logger logger = Logger.getLogger(URLTag.class.getName());
49  
50      /**
51       * 
52       */
53      private static final long serialVersionUID = 4433903132736259601L;
54  
55      /**
56       * The universal version identifier.
57       */
58  
59      /**
60       * The base url to use when constructing the url.
61       */
62      private String   baseURL;
63      
64      /**
65       * The query to use when constructing the url.
66       */
67      private String   query;
68      
69      /**
70       * The parameter names to exclude from the quertyString. Commasseperated string.
71       */
72      private String   excludedQueryStringParameters;
73      
74      /**
75       * The parameter that controls if the full servername etc should be included in the base url.
76       */
77      private boolean fullBaseUrl = false;
78      
79      /**
80       * The parameters to use when constructing the url.
81       */
82      private List   parameters; // type: <String>, format: <name>=<value>
83      
84      /**
85       * The names of all parameters added.
86       */
87      private Map   parameterNames; // <type>: <String>-><String>
88      
89      /**
90       * Tells the tag if the nice uri option should be disabled if enabled.
91       */
92      
93      private boolean disableNiceURI = false;
94      
95      /**
96       * Tells if parameter should be allowed even though there are parameters with that name
97       */
98      private boolean allowMultipleArguments = false;
99      
100     /**
101      * Default constructor.
102      */
103     public URLTag()
104     {
105         super();
106     }
107 
108     /**
109      * Initializes the parameters to make it accessible for the children tags (if any).
110      * 
111      * @return indication of whether to evaluate the body or not.
112      * @throws JspException if an error occurred while processing this tag.
113      */
114     public int doStartTag() throws JspException   
115     {
116         return EVAL_BODY_INCLUDE;
117     }
118     
119     /**
120      * Generates the url and either sets the result attribute or writes the url
121      * to the output stream. 
122      * 
123      * @return indication of whether to continue evaluating the JSP page.
124      * @throws JspException if an error occurred while processing this tag.
125      */
126     public int doEndTag() throws JspException  
127     {
128         addQueryParameters();
129         produceResult(generateURL());
130         parameters = null;
131         parameterNames = null;
132         return EVAL_PAGE;
133     }
134 
135     /**
136      * Returns the parameters to use when constructing the url.
137      * 
138      * @return the parameters to use when constructing the url.
139      */
140     private List   getParameters()
141     {
142         if(parameters == null)
143         {
144             parameters = new ArrayList  ();
145         }
146         return parameters;
147     }
148     
149     /**
150      * Returns the name of all parameters that has been added.
151      * 
152      * @return the name of all parameters that has been added.
153      */
154     private Map   getParameterNames()
155     {
156         if(parameterNames == null)
157         {
158             parameterNames = new HashMap  ();
159         }
160         return parameterNames;
161     }
162     
163     /**
164      * 
165      */
166     protected final void addParameter(final String   name, final String   value)
167     {
168         getParameters().add(name + "=" + value);
169         getParameterNames().put(name, name);
170     }
171     
172     /**
173      * Returns the url attribute if present; otherwise the url is taken from the request.
174      * 
175      * @return the url attribute if present; otherwise the url is taken from the request.
176      */
177     private String   getBaseURL()
178     {
179         String   newBaseUrl = "";
180         try
181         {
182             logger.info("fullBaseUrl:" + fullBaseUrl);
183             if(this.fullBaseUrl)
184             {
185                 int indexOfProtocol = getRequest().getRequestURL().indexOf("://");
186                 int indexFirstSlash = getRequest().getRequestURL().indexOf("/", indexOfProtocol + 3);
187                 String   base = null;
188                 if(indexFirstSlash > -1)
189                     base = getRequest().getRequestURL().substring(0, indexFirstSlash);
190                 else
191                     base = getRequest().getRequestURL().substring(0);
192                 
193                 String   currentPageUrl = this.getController().getCurrentPageUrl().toString();
194                 currentPageUrl = currentPageUrl.split("\\?")[0];
195                 newBaseUrl = (baseURL == null) ? base + currentPageUrl : baseURL;           
196             }
197             else
198             {
199                 String   currentPageUrl = this.getController().getCurrentPageUrl().toString();
200                 currentPageUrl = currentPageUrl.split("\\?")[0];
201                 newBaseUrl = (baseURL == null) ? currentPageUrl : baseURL;          
202             }
203         }
204         catch(Exception   e)
205         {
206             logger.warn("Error:", e);
207             newBaseUrl = (baseURL == null) ? getRequest().getRequestURL().toString() : baseURL;
208         }
209         logger.info("newBaseUrl:" + newBaseUrl);
210         return newBaseUrl;
211     }
212     
213     /**
214      * Returns the query attribute if present; otherwise the query is taken from the request.
215      * 
216      * @return the query attribute if present; otherwise the query is taken from the request.
217      */
218     private String   getQuery()
219     {
220         String   q = (query == null) ? getRequest().getQueryString() : query;
221         if(q != null && (q.startsWith("?") || q.startsWith("&")))
222         {
223             return q.substring(1);
224         }
225         return q;
226     }
227     
228     /**
229      * Returns the (http) request object.
230      * 
231      * @return the (http) request object.
232      */
233     private final HttpServletRequest   getRequest()
234     {
235         return (HttpServletRequest  ) pageContext.getRequest();
236     }
237     
238     /**
239      * Adds the parameter from the query string to the parameters to use
240      * when constructing the url. If a parameter present in the query already
241      * exists in the parameters, the query parameter will be skipped.
242      * 
243      * @throws JspException if the format of the query string is illegal.
244      */
245     private void addQueryParameters() throws JspException  
246     {
247         if(getQuery() != null)
248         {
249             for(final StringTokenizer   st = new StringTokenizer  (getQuery(), "&"); st.hasMoreTokens(); )
250             {
251                 final String   token = st.nextToken();
252                 final StringTokenizer   parameter = new StringTokenizer  (token, "=");
253                 if(parameter.countTokens() == 0 || parameter.countTokens() > 2)
254                 {
255                     throw new JspTagException  ("Illegal query parameter [" + token + "].");
256                 }
257                 final String   name  = parameter.nextToken();
258                 final String   value = parameter.hasMoreTokens() ? parameter.nextToken() : "";
259                 if(allowMultipleArguments || !getParameterNames().containsKey(name))
260                 {
261                     if(excludedQueryStringParameters == null || excludedQueryStringParameters.indexOf(name) == -1)
262                         addParameter(name, value);
263                 }
264             }
265         }
266     }
267     
268     /**
269      * Generates the url string.
270      * 
271      * @return the url.
272      */
273     public String   generateURL() 
274     {
275         if(!getParameters().isEmpty()) 
276         {
277             StringBuffer   sb = new StringBuffer  ();
278             for(Iterator   i = getParameters().iterator(); i.hasNext(); ) 
279             {
280                 String   parameter = i.next().toString();
281                 sb.append(parameter + (i.hasNext() ? "&" : ""));
282             }
283             if(getBaseURL().indexOf("?") > -1)
284                 return getBaseURL() + (sb.toString().length() > 0 ? "&" + sb.toString() : "");
285             else
286                 return getBaseURL() + (sb.toString().length() > 0 ? "?" + sb.toString() : "");
287         }
288         return getBaseURL();
289     }
290 
291     /**
292      * Sets the base url attribute.
293      * 
294      * @param baseURL the base url to use.
295      * @throws JspException if an error occurs while evaluating base url parameter.
296      */
297     public void setBaseURL(final String   baseURL) throws JspException  
298     {
299         this.baseURL = evaluateString("url", "baseURL", baseURL);
300     }
301 
302     /**
303      * Sets the query attribute.
304      * 
305      * @param query the query to use.
306      * @throws JspException if an error occurs while evaluating query parameter.
307      */
308     public void setQuery(final String   query) throws JspException  
309     {
310         this.query = evaluateString("url", "query", query);
311     }
312     
313     public void setExcludedQueryStringParameters(String   excludedQueryStringParameters) throws JspException  
314     {
315         this.excludedQueryStringParameters = evaluateString("url", "excludedQueryStringParameters", excludedQueryStringParameters);
316     }
317 
318     public void setFullBaseUrl(boolean fullBaseUrl)
319     {
320         this.fullBaseUrl = fullBaseUrl;
321     }
322     
323     public void setDisableNiceURI(boolean disableNiceURI)
324     {
325         this.disableNiceURI = disableNiceURI;
326     }
327 
328     public void setAllowMultipleArguments(boolean allowMultipleArguments)
329     {
330         this.allowMultipleArguments = allowMultipleArguments;
331     }
332 }
333
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