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19  
20  package org.apache.james.transport.mailets;
21  
22  import org.apache.avalon.cornerstone.services.datasources.DataSourceSelector;
23  import org.apache.avalon.excalibur.datasource.DataSourceComponent;
24  import org.apache.avalon.framework.service.ServiceManager;
25  import org.apache.james.Constants;
26  import org.apache.james.util.JDBCUtil;
27  import org.apache.mailet.MailAddress;
28  import org.apache.mailet.MailetException;
29  
30  import javax.mail.MessagingException;
31  
32  import java.sql.Connection;
33  import java.sql.DatabaseMetaData;
34  import java.sql.PreparedStatement;
35  import java.sql.ResultSet;
36  import java.sql.SQLException;
37  import java.util.Collection;
38  import java.util.Iterator;
39  import java.util.Map;
40  
41  /***
42   * Implements a Virtual User Table for JAMES.  Derived from the
43   * JDBCAlias mailet, but whereas that mailet uses a simple map from a
44   * source address to a destination address, this handles simple
45   * wildcard selection, verifies that a catchall address is for a domain
46   * in the Virtual User Table, and handles forwarding.
47   *
48   * JDBCVirtualUserTable does not provide any administation tools.
49   * You'll have to create the VirtualUserTable yourself.  The standard
50   * configuration is as follows:
51   *
52   * CREATE TABLE VirtualUserTable
53   * (
54   *  user varchar(64) NOT NULL default '',
55   *  domain varchar(255) NOT NULL default '',
56   *  target_address varchar(255) NOT NULL default '',
57   *  PRIMARY KEY (user,domain)
58   * );
59   *
60   * The user column specifies the username of the virtual recipient, the domain
61   * column the domain of the virtual recipient, and the target_address column
62   * the email address of the real recipient. The target_address column can contain
63   * just the username in the case of a local user, and multiple recipients can be
64   * specified in a list separated by commas, semi-colons or colons.
65   *
66   * The standard query used with VirtualUserTable is:
67   *
68   * select VirtualUserTable.target_address from VirtualUserTable, VirtualUserTable as VUTDomains
69   * where (VirtualUserTable.user like ? or VirtualUserTable.user like "\%")
70   * and (VirtualUserTable.domain like ?
71   * or (VirtualUserTable.domain like "\%" and VUTDomains.domain like ?))
72   * order by concat(VirtualUserTable.user,'@',VirtualUserTable.domain) desc limit 1
73   *
74   * For a given [user, domain, domain] used with the query, this will
75   * match as follows (in precedence order):
76   *
77   * 1. user@domain    - explicit mapping for user@domain
78   * 2. user@%         - catchall mapping for user anywhere
79   * 3. %@domain       - catchall mapping for anyone at domain
80   * 4. null           - no valid mapping
81   *
82   * You need to set the connection.  At the moment, there is a limit to
83   * what you can change regarding the SQL Query, because there isn't a
84   * means to specify where in the query to replace parameters. [TODO]
85   *
86   * <mailet match="All" class="JDBCVirtualUserTable">
87   *   <table>db://maildb/VirtualUserTable</table>
88   *   <sqlquery>sqlquery</sqlquery>
89   * </mailet>
90   */
91  public class JDBCVirtualUserTable extends AbstractVirtualUserTable
92  {
93      protected DataSourceComponent datasource;
94  
95      /***
96       * The query used by the mailet to get the alias mapping
97       */
98      protected String query = null;
99  
100     /***
101      * The JDBCUtil helper class
102      */
103     private final JDBCUtil theJDBCUtil = new JDBCUtil() {
104         protected void delegatedLog(String logString) {
105             log("JDBCVirtualUserTable: " + logString);
106         }
107     };
108 
109     /***
110      * Initialize the mailet
111      */
112     public void init() throws MessagingException {
113         if (getInitParameter("table") == null) {
114             throw new MailetException("Table location not specified for JDBCVirtualUserTable");
115         }
116 
117         String tableURL = getInitParameter("table");
118 
119         String datasourceName = tableURL.substring(5);
120         int pos = datasourceName.indexOf("/");
121         String tableName = datasourceName.substring(pos + 1);
122         datasourceName = datasourceName.substring(0, pos);
123         Connection conn = null;
124 
125         try {
126             ServiceManager componentManager = (ServiceManager)getMailetContext().getAttribute(Constants.AVALON_COMPONENT_MANAGER);
127             // Get the DataSourceSelector service
128             DataSourceSelector datasources = (DataSourceSelector)componentManager.lookup(DataSourceSelector.ROLE);
129             // Get the data-source required.
130             datasource = (DataSourceComponent)datasources.select(datasourceName);
131 
132             conn = datasource.getConnection();
133 
134             // Check if the required table exists. If not, complain.
135             DatabaseMetaData dbMetaData = conn.getMetaData();
136             // Need to ask in the case that identifiers are stored, ask the DatabaseMetaInfo.
137             // Try UPPER, lower, and MixedCase, to see if the table is there.
138             if (!(theJDBCUtil.tableExists(dbMetaData, tableName))) {
139                 StringBuffer exceptionBuffer =
140                                               new StringBuffer(128)
141                                               .append("Could not find table '")
142                                               .append(tableName)
143                                               .append("' in datasource '")
144                                               .append(datasourceName)
145                                               .append("'");
146                 throw new MailetException(exceptionBuffer.toString());
147             }
148 
149             //Build the query
150             query = getInitParameter("sqlquery","select VirtualUserTable.target_address from VirtualUserTable, VirtualUserTable as VUTDomains where (VirtualUserTable.user like ? or VirtualUserTable.user like '//%') and (VirtualUserTable.domain like ? or (VirtualUserTable.domain like '//%' and VUTDomains.domain like ?)) order by concat(VirtualUserTable.user,'@',VirtualUserTable.domain) desc limit 1");
151         } catch (MailetException me) {
152             throw me;
153         } catch (Exception e) {
154             throw new MessagingException("Error initializing JDBCVirtualUserTable", e);
155         } finally {
156             theJDBCUtil.closeJDBCConnection(conn);
157         }
158     }
159 
160     /***
161      * Map any virtual recipients to real recipients using the configured
162      * JDBC connection, table and query.
163      * 
164      * @param recipientsMap the mapping of virtual to real recipients
165      */
166     protected void mapRecipients(Map recipientsMap) throws MessagingException {
167         Connection conn = null;
168         PreparedStatement mappingStmt = null;
169 
170         Collection recipients = recipientsMap.keySet();
171 
172         try {
173             conn = datasource.getConnection();
174             mappingStmt = conn.prepareStatement(query);
175 
176             for (Iterator i = recipients.iterator(); i.hasNext(); ) {
177                 ResultSet mappingRS = null;
178                 try {
179                     MailAddress source = (MailAddress)i.next();
180                     mappingStmt.setString(1, source.getUser());
181                     mappingStmt.setString(2, source.getHost());
182                     mappingStmt.setString(3, source.getHost());
183                     mappingRS = mappingStmt.executeQuery();
184                     if (mappingRS.next()) {
185                         String targetString = mappingRS.getString(1);
186                         recipientsMap.put(source, targetString);
187                     }
188                 } finally {
189                     theJDBCUtil.closeJDBCResultSet(mappingRS);
190                 }
191             }
192         } catch (SQLException sqle) {
193             throw new MessagingException("Error accessing database", sqle);
194         } finally {
195             theJDBCUtil.closeJDBCStatement(mappingStmt);
196             theJDBCUtil.closeJDBCConnection(conn);
197         }
198     }
199 
200     public String getMailetInfo() {
201         return "JDBC Virtual User Table mailet";
202     }
203 }