DuplicatedKeyValidator


1   package dinamica.validators;
2   
3   import java.util.HashMap  ;
4   import javax.servlet.http.HttpServletRequest  ;
5   import dinamica.*;
6   
7   /**
8    * Generic Validator to test if a record key is duplicated,
9    * requires the following custom attributes:<br>
10   * <ul>
11   * <li> sql: query to find any related record. You may use field makers
12   * that will be replaced by the corresponding request parameters passed
13   * as a recordset to the isValid method.
14   * </ul>
15   * <br>If you don't use the SQL query you may use the
16   * attributes shown below (not recommended).
17   * <ul>
18   * <li> table: name of the search table.
19   * <li> column: name of the search column, also the
20   * name of the parameter whose value will be used.
21   * <li> varchar: true|false indicates if the column is of type varchar or alike,
22   * this is used to demarcate the column search value with the proper delimiter, if any.
23   * </ul>
24   * <br>
25   * Works only for text or numeric values, dates not allowed.
26   * <br><br>
27   * Creation date: 10/feb/2004<br>
28   * Last Update: 10/feb/2004<br>
29   * (c) 2004 Martin Cordova<br>
30   * This code is released under the LGPL license<br>
31   * @author Martin Cordova (dinamica@martincordova.com)
32   * */
33  
34  public class DuplicatedKeyValidator extends AbstractValidator
35  {
36  
37      /* (non-Javadoc)
38       * @see dinamica.AbstractValidator#isValid(javax.servlet.http.HttpServletRequest, dinamica.Recordset, java.util.HashMap)
39       */
40      public boolean isValid(
41          HttpServletRequest   req,
42          Recordset inputParams,
43          HashMap   attribs)
44          throws Throwable  
45      {
46          
47          boolean flag = true;
48          
49          //get db channel
50          Db db = getDb();
51  
52          //detect if sql parameter was passed to the validator
53          boolean bSql = attribs.containsKey("sql");
54  
55          String   sql = "";
56  
57          if (!bSql)
58          {
59              //validate plugin configuration
60              boolean b1 = attribs.containsKey("table");
61              if (!b1)
62                  throw new Throwable  ("Bad configuration - 'table' attribute not found.");
63              boolean b2 = attribs.containsKey("column");
64              if (!b2)
65                  throw new Throwable  ("Bad configuration - 'column' attribute not found.");
66              boolean b3 = attribs.containsKey("varchar");
67              if (!b3)
68                  throw new Throwable  ("Bad configuration - 'varchar' attribute not found.");
69      
70              //define value enclosing character (quote or nothing)
71              String   delim = "";
72              String   isVarchar = (String  )attribs.get("varchar");
73              if (isVarchar.equals("true"))
74                  delim = "'";
75      
76              //get db parameters
77              String   table = (String  )attribs.get("table");
78              String   col = (String  )attribs.get("column");
79      
80              //get input value
81              String   value = String.valueOf(inputParams.getValue(col));
82      
83              //build sql
84              sql = "select " + col + " from " + table + " where " + col + " = " + delim + value + delim; 
85          }
86          else
87          {
88              String   query = (String  )attribs.get("sql");
89              sql = getResource(query);
90              sql = getSQL(sql, inputParams);
91          }
92          
93          //execute sql
94          Recordset rs = db.get(sql);
95          if (rs.getRecordCount()>0)
96              flag = false;
97  
98          return flag;
99          
100     }
101 
102 }
103
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