Created a site identifier that reads data from a JDBC table.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@410 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/samskivert/src/java/com/samskivert/servlet/JDBCTableSiteIdentifier.java

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+//
+// $Id: JDBCTableSiteIdentifier.java,v 1.1 2001/11/01 21:34:19 mdb Exp $
+//
+// samskivert library - useful routines for java programs
+// Copyright (C) 2001 Michael Bayne
+// 
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.servlet;
+
+import java.sql.Connection;
+import java.sql.Statement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import java.util.ArrayList;
+import javax.servlet.http.HttpServletRequest;
+import com.samskivert.io.PersistenceException;
+
+import com.samskivert.jdbc.ConnectionProvider;
+import com.samskivert.jdbc.DatabaseLiaison;
+import com.samskivert.jdbc.SimpleRepository;
+import com.samskivert.jdbc.JDBCUtil;
+import com.samskivert.util.HashIntMap;
+
+/**
+ * Accomplishes the process of site identification based on a mapping from
+ * domains (e.g. samskivert.com) to site identifiers that is maintained in
+ * a database table, accessible via JDBC (hence the name).
+ *
+ * <p> There are two tables, one that maps domains to site identifiers and
+ * another that maps site identifiers to site strings. These are both
+ * loaded at construct time and refreshed periodically in the course of
+ * normal operation.
+ */
+public class JDBCTableSiteIdentifier implements SiteIdentifier
+{
+    /** The database identifier used to obtain a connection from our
+     * connection provider. The value is <code>sitedb</code> which you'll
+     * probably need to know to provide the proper configuration to your
+     * connection provider. */
+    public static final String SITE_IDENTIFIER_IDENT = "sitedb";
+
+    /**
+     * Constructs a JDBC table site identifier with the supplied
+     * connection provider from which to obtain its database connection.
+     *
+     * @see #SITE_IDENTIFIER_IDENT
+     */
+    public JDBCTableSiteIdentifier (ConnectionProvider conprov)
+        throws PersistenceException
+    {
+        _repo = new SiteIdentifierRepository(conprov);
+        // load up our site data
+        _repo.refreshSiteData();
+    }
+
+    // documentation inherited
+    public int identifySite (HttpServletRequest req)
+    {
+        String serverName = req.getServerName();
+
+        // scan for the mapping that matches the specified domain
+        int msize = _mappings.size();
+        for (int i = 0; i < msize; i++) {
+            SiteMapping mapping = (SiteMapping)_mappings.get(i);
+            if (serverName.endsWith(mapping.domain)) {
+                return mapping.siteId;
+            }
+        }
+
+        // if we matched nothing, return the default id
+        return DEFAULT_SITE_ID;
+    }
+
+    // documentation inherited
+    public String getSiteString (int siteId)
+    {
+        String stringId = (String)_sites.get(siteId);
+        return (stringId == null) ? DEFAULT_SITE_STRING : stringId;
+    }
+
+    /**
+     * Used to load information from the site database.
+     */
+    protected class SiteIdentifierRepository
+        extends SimpleRepository implements SimpleRepository.Operation
+    {
+        public SiteIdentifierRepository (ConnectionProvider conprov)
+        {
+            super(conprov, SITE_IDENTIFIER_IDENT);
+        }
+
+        public void refreshSiteData ()
+            throws PersistenceException
+        {
+            // we are the operation!
+            execute(this);
+        }
+
+        public Object invoke (Connection conn, DatabaseLiaison liaison)
+            throws PersistenceException, SQLException
+        {
+            Statement stmt = conn.createStatement();
+            try {
+                // first load up the list of sites
+                String query = "select siteId, stringId from sites";
+                ResultSet rs = stmt.executeQuery(query);
+                HashIntMap sites = new HashIntMap();
+                while (rs.next()) {
+                    sites.put(rs.getInt(1), rs.getString(2));
+                }
+                _sites = sites;
+
+                // now load up the domain mappings
+                query = "select domain, siteId from sites";
+                rs = stmt.executeQuery(query);
+                ArrayList mappings = new ArrayList();
+                while (rs.next()) {
+                    SiteMapping mapping = new SiteMapping();
+                    mapping.domain = rs.getString(1);
+                    mapping.siteId = rs.getInt(2);
+                    mappings.add(mapping);
+                }
+                _mappings = mappings;
+
+                // nothing to return
+                return null;
+
+            } finally {
+                JDBCUtil.close(stmt);
+            }
+        }
+    }
+
+    /**
+     * Used to track domain to site identifier mappings.
+     */
+    protected static class SiteMapping implements Comparable
+    {
+        /** The domain to match. */
+        public String domain;
+
+        /** The site identifier for the associated domain. */
+        public int siteId;
+
+        /**
+         * Site mappings sort from most specific (www.yahoo.com) to least
+         * specific (yahoo.com).
+         */
+        public int compareTo (Object other)
+        {
+            if (other instanceof SiteMapping) {
+                SiteMapping orec = (SiteMapping)other;
+
+                // if the domains are equal, we're equal
+                if (domain.equals(orec.domain)) {
+                    return 0;
+
+                } else if (domain.endsWith(orec.domain)) {
+                    // if our domain is a subset of their domain, they are
+                    // after us
+                    return 1;
+
+                } else {
+                    return -1;
+                }
+
+            } else {
+                // no comparablo
+                return -1;
+            }
+        }
+    }
+
+    /** The repository through which we load up site identifier
+     * information. */
+    protected SiteIdentifierRepository _repo;
+
+    /** The list of domain to site identifier mappings ordered from most
+     * specific domain to least specific. */
+    protected ArrayList _mappings = new ArrayList();
+
+    /** The mapping from integer site identifiers to string site
+     * identifiers. */
+    protected HashIntMap _sites = new HashIntMap();
+}

projects/samskivert/src/sql/create_site_tables.mysql

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+/**
+ * $Id: create_site_tables.mysql,v 1.1 2001/11/01 21:34:19 mdb Exp $
+ *
+ * Creates the necessary database tables in MySQL for the JDBC table site
+ * identifier.
+ */
+
+/**
+ * The sites table contains a row for every site, along with its human
+ * readable name identifier.
+ */
+DROP TABLE IF EXISTS sites;
+CREATE TABLE sites (
+    siteId    INTEGER(5) PRIMARY KEY NOT NULL AUTO_INCREMENT,
+    stringId  VARCHAR(24) NOT NULL
+);
+
+/**
+ * The domains table contains a row for every domain to site mapping.
+ */
+DROP TABLE IF EXISTS domains;
+CREATE TABLE domains (
+    domain  VARCHAR(128) PRIMARY KEY NOT NULL,
+    siteId  INTEGER(5) NOT NULL
+);