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25
26
29
30 package net.killingar.servlet.filter;
31
32 import javax.naming.Context  ;
33 import javax.naming.InitialContext ;
34 import javax.naming.NamingException ;
35 import javax.sql.DataSource ;
36 import java.sql.*;
37 import java.util.*;
38 import javax.servlet.*;
39 import javax.servlet.http.*;
40
41 public class RedirectFilter extends GenericFilter
42 {
43 private static final String datasource = "java:comp/env/jdbc/RedirectDS";
44 private static Context ctx;
45 private static DataSource ds;
46 private static Map map = new HashMap();
47 private static long lastUpdateTime = 0;
48
49
50
53 public static Connection getNewConnection() throws SQLException
54 {
55 try
56 {
57 if (ctx == null)
58 ctx = new InitialContext ();
59 if (ds == null)
60 ds = (DataSource ) ctx.lookup(datasource);
61 return ds.getConnection();
62 }
63 catch (NamingException e)
64 {
65 e.printStackTrace();
66 throw new SQLException(e.getMessage());
67 }
68 }
69
70
73 public static void closeAll(Connection c, Statement statement, ResultSet result)
74 {
75 try
76 {
77 if (result != null)result.close();
78 if (statement != null)statement.close();
79 if (c != null)c.close();
80 }
81 catch (SQLException e){}
82 }
83 public static void closeAll(Connection c, Statement statement) throws SQLException { closeAll(c, statement, null); }
84 public static void closeAll(Connection c) throws SQLException { closeAll(c, null, null); }
85
86 public void doFilter(final ServletRequest inRequest, final ServletResponse inResponse, FilterChain inChain) throws java.io.IOException , javax.servlet.ServletException
87 {
88 update();
89
90 HttpServletRequest request = (HttpServletRequest)inRequest;
91 HttpServletResponse response = (HttpServletResponse)inResponse;
92
93 String s = (String )map.get(request.getServerName());
94 if (s != null)
95 {
96 response.sendRedirect(s);
97 return;
98 }
99
100 inChain.doFilter(inRequest, inResponse);
101 }
102
103 private static void update()
104 {
105 if (System.currentTimeMillis()-lastUpdateTime < 1000)
106 return;
107
108 Connection c = null;
109 PreparedStatement statement = null;
110 ResultSet result = null;
111 try
112 {
113 c = getNewConnection();
114 statement = c.prepareStatement("select * from RedirectMapping where LastChanged > ?");
115 statement.setTimestamp(1, new Timestamp(lastUpdateTime));
116 lastUpdateTime = System.currentTimeMillis();
117 result = statement.executeQuery();
118
119 while (result.next())
120 {
121 map.put(result.getString("fromHost"), result.getString("toAddress"));
122 }
123 }
124 catch (SQLException e)
125 {
126 }
127 finally
128 {
129 closeAll(c, statement, result);
130 }
131 }
132
133 public static Map getMap()
134 {
135 update();
136 return Collections.unmodifiableMap(map);
137 }
138
139 public static void set(String from, String to) throws SQLException
140 {
141 Connection c = null;
142 PreparedStatement statement = null;
143 try
144 {
145 c = getNewConnection();
146 statement = c.prepareStatement("delete from RedirectMapping where fromHost = ?");
147 statement.setString(1, from);
148 statement.executeUpdate();
149 statement.close();
150
151 statement = c.prepareStatement("insert into RedirectMapping(fromHost, toAddress, lastChanged) values(?, ?, NOW())");
152 statement.setString(1, from);
153 statement.setString(2, to);
154 statement.executeUpdate();
155
156 map.put(from, to);
157 }
158 finally
159 {
160 closeAll(c, statement, null);
161 }
162 }
163 } |
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