SQLPatternTransformer


1   package dinamica.validators;
2   
3   import java.util.HashMap  ;
4   import javax.servlet.http.HttpServletRequest  ;
5   import dinamica.*;
6   
7   
8   /**
9    * This validator transforms the value (if not null) of the corresponding
10   * parameter, by appending a '%' at the end of the text or by enclosing the
11   * the value between '%' characters.<br>
12   * It is used to create search patterns for SQL queries like 'value starts with..' that can
13   * be used in sql LIKE expressions. Always returns TRUE.<br>
14   * As a preventtive measure, all occurrences of the '%' character in the parameter's value 
15   * will be erased before applying the transformation.
16   * <br><br>
17   * Requires the following custom attributes:<br>
18   * <ul>
19   * <li> parameter: Name of the request parameter to transform. This parameter
20   * MUST be defined in validator.xml and must be of type VARCHAR.
21   * <li> rule: a string that denotes the possible transformation, accepted
22   * values are 'like' and 'contains'.
23   * </ul>
24   *  
25   * (c) 2005 Martin Cordova<br>
26   * This code is released under the LGPL license<br>
27   * Dinamica Framework - http://www.martincordova.com<br>
28   * @author Martin Cordova (dinamica@martincordova.com)
29   * */
30  public class SQLPatternTransformer extends AbstractValidator {
31  
32      /* (non-Javadoc)
33       * @see dinamica.AbstractValidator#isValid(javax.servlet.http.HttpServletRequest, dinamica.Recordset, java.util.HashMap)
34       */
35      public boolean isValid(HttpServletRequest   req, Recordset inputParams,
36              HashMap   attribs) throws Throwable   {
37  
38          boolean bParam = attribs.containsKey("parameter");
39          if (!bParam)
40              throw new Throwable  ("[" + this.getClass().getName() + "] Missing attribute [parameter] in validator.xml");
41          
42          boolean bRule = attribs.containsKey("rule");
43          if (!bRule)
44              throw new Throwable  ("[" + this.getClass().getName() + "] Missing attribute [rule] in validator.xml");
45          
46          String   rule = (String  )attribs.get("rule");
47          
48          if (!rule.equalsIgnoreCase("like") && !rule.equalsIgnoreCase("contains"))
49              throw new Throwable  ("[" + this.getClass().getName() + "] Invalid attribute value [rule] in validator.xml: " + rule + " - Accepted values are 'like' or 'contains'");
50          
51          String   paramName = (String  )attribs.get("parameter");
52          if (!inputParams.isNull(paramName))
53          {
54              String   value = inputParams.getString(paramName);
55              value = StringUtil.replace(value, "%", "");
56              if (rule.equalsIgnoreCase("like"))
57                  value = value + "%";
58              if (rule.equalsIgnoreCase("contains"))
59                  value = "%" + value + "%";
60              inputParams.setValue(paramName, value);
61          }
62          
63          return true;
64      }
65  
66  }
67
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Free Books Free Magazines
Popular Tags