1   /*
    2    * Copyright (c) 2002-2007 by OpenSymphony
    3    * All rights reserved.
    4    */
    5   package com.opensymphony.xwork2.interceptor;
    6   
    7   import com.opensymphony.xwork2.ActionContext;
    8   import com.opensymphony.xwork2.ActionInvocation;
    9   import com.opensymphony.xwork2.util.TextParseUtil;
   10   import com.opensymphony.xwork2.util.logging.Logger;
   11   import com.opensymphony.xwork2.util.logging.LoggerFactory;
   12   
   13   import java.util.Collections;
   14   import java.util.Map;
   15   import java.util.Set;
   16   
   17   /**
   18    * <!-- START SNIPPET: description -->
   19    * This is a simple XWork interceptor that allows parameters (matching
   20    * one of the paramNames attribute csv value) to be 
   21    * removed from the parameter map if they match a certain value
   22    * (matching one of the paramValues attribute csv value), before they 
   23    * are set on the action. A typical usage would be to want a dropdown/select 
   24    * to map onto a boolean value on an action. The select had the options 
   25    * none, yes and no with values -1, true and false. The true and false would 
   26    * map across correctly. However the -1 would be set to false. 
   27    * This was not desired as one might needed the value on the action to stay null. 
   28    * This interceptor fixes this by preventing the parameter from ever reaching 
   29    * the action.
   30    * <!-- END SNIPPET: description -->
   31    * 
   32    * 
   33    * <!-- START SNIPPET: parameters -->
   34    * <ul>
   35    * 	<li>paramNames - A comma separated value (csv) indicating the parameter name 
   36    * 								    whose param value should be considered that if they match any of the
   37    *                                     comma separated value (csv) from paramValues attribute, shall be 
   38    *                                     removed from the parameter map such that they will not be applied
   39    *                                     to the action</li>
   40    * 	<li>paramValues - A comma separated value (csv) indicating the parameter value that if 
   41    * 							      matched shall have its parameter be removed from the parameter map 
   42    * 							      such that they will not be applied to the action</li>
   43    * </ul>
   44    * <!-- END SNIPPET: parameters -->
   45    * 
   46    * 
   47    * <!-- START SNIPPET: extending -->
   48    * No intended extension point
   49    * <!-- END SNIPPET: extending -->
   50    * 
   51    * <pre>
   52    * <!-- START SNIPPET: example -->
   53    *	
   54    * &lt;action name="sample" class="org.martingilday.Sample"&gt;
   55    * 	&lt;interceptor-ref name="paramRemover"&gt;
   56    *   		&lt;param name="paramNames"&gt;aParam,anotherParam&lt;/param&gt;
   57    *   		&lt;param name="paramValues"&gt;--,-1&lt;/param&gt;
   58    * 	&lt;/interceptor-ref&gt;
   59    * 	&lt;interceptor-ref name="defaultStack" /&gt;
   60    * 	...
   61    * &lt;/action&gt;
   62    *  
   63    * <!-- END SNIPPET: example -->
   64    * </pre>
   65    *  
   66    *  
   67    * @author martin.gilday
   68    */
   69   public class ParameterRemoverInterceptor extends AbstractInterceptor {
   70   
   71   	private static final Logger LOG = LoggerFactory.getLogger(ParameterRemoverInterceptor.class);
   72   
   73   	private static final long serialVersionUID = 1;
   74   
   75   	private Set<String> paramNames = Collections.emptySet();
   76   
   77   	private Set<String> paramValues = Collections.emptySet();
   78   
   79   	
   80   	/**
   81   	 * Decide if the parameter should be removed from the parameter map based on
   82   	 * <code>paramNames</code> and <code>paramValues</code>.
   83   	 * 
   84   	 * @see com.opensymphony.xwork2.interceptor.AbstractInterceptor
   85   	 */
   86   	@Override
   87   	public String intercept(ActionInvocation invocation) throws Exception {
   88   		if (!(invocation.getAction() instanceof NoParameters)
   89   				&& (null != this.paramNames)) {
   90   			ActionContext ac = invocation.getInvocationContext();
   91   			final Map<String, Object> parameters = ac.getParameters();
   92   
   93   			if (parameters != null) {
   94                   for (String removeName : paramNames) {
   95                       // see if the field is in the parameter map
   96                       if (parameters.containsKey(removeName)) {
   97   
   98                           try {
   99                               String[] values = (String[]) parameters
  100                                       .get(removeName);
  101                               String value = values[0];
  102                               if (null != value && this.paramValues.contains(value)) {
  103                                   parameters.remove(removeName);
  104                               }
  105                           } catch (Exception e) {
  106                               LOG.error("Failed to convert parameter to string", e);
  107                           }
  108                       }
  109                   }
  110   			}
  111   		}
  112   		return invocation.invoke();
  113   	}
  114   
  115   	/**
  116   	 * Allows <code>paramNames</code> attribute to be set as comma-separated-values (csv).
  117   	 * 
  118   	 * @param paramNames the paramNames to set
  119   	 */
  120   	public void setParamNames(String paramNames) {
  121   		this.paramNames = TextParseUtil.commaDelimitedStringToSet(paramNames);
  122   	}
  123   
  124   
  125   	/**
  126   	 * Allows <code>paramValues</code> attribute to be set as a comma-separated-values (csv).
  127   	 * 
  128   	 * @param paramValues the paramValues to set
  129   	 */
  130   	public void setParamValues(String paramValues) {
  131   		this.paramValues = TextParseUtil.commaDelimitedStringToSet(paramValues);
  132   	}
  133   }
  134