src/org/cacert/gigi/database/DatabaseConnection.java

   1 package org.cacert.gigi.database;
   2
   3 import java.sql.Connection;
   4 import java.sql.DriverManager;
   5 import java.sql.PreparedStatement;
   6 import java.sql.ResultSet;
   7 import java.sql.SQLException;
   8 import java.util.HashMap;
   9 import java.util.Properties;
  10 import java.sql.Statement;
  11
  12 public class DatabaseConnection {
  13         public static final int CONNECTION_TIMEOUT = 24 * 60 * 60;
  14         Connection c;
  15         HashMap<String, PreparedStatement> statements = new HashMap<String, PreparedStatement>();
  16         private static Properties credentials;
  17         Statement adHoc;
  18
  19         public DatabaseConnection() {
  20                 try {
  21                         Class.forName(credentials.getProperty("sql.driver"));
  22                 } catch (ClassNotFoundException e) {
  23                         e.printStackTrace();
  24                 }
  25                 tryConnect();
  26
  27         }
  28
  29         private void tryConnect() {
  30                 try {
  31                         c = DriverManager.getConnection(credentials.getProperty("sql.url") + "?zeroDateTimeBehavior=convertToNull",
  32                                 credentials.getProperty("sql.user"), credentials.getProperty("sql.password"));
  33                         PreparedStatement ps = c.prepareStatement("SET SESSION wait_timeout=?;");
  34                         ps.setInt(1, CONNECTION_TIMEOUT);
  35                         ps.execute();
  36                         ps.close();
  37                         adHoc = c.createStatement();
  38                 } catch (SQLException e) {
  39                         e.printStackTrace();
  40                 }
  41         }
  42
  43         public PreparedStatement prepare(String query) throws SQLException {
  44                 ensureOpen();
  45                 PreparedStatement statement = statements.get(query);
  46                 if (statement == null) {
  47                         statement = c.prepareStatement(query, Statement.RETURN_GENERATED_KEYS);
  48                         statements.put(query, statement);
  49                 }
  50                 return statement;
  51         }
  52
  53         long lastAction = System.currentTimeMillis();
  54
  55         private void ensureOpen() {
  56                 if (System.currentTimeMillis() - lastAction > CONNECTION_TIMEOUT * 1000L) {
  57                         try {
  58                                 ResultSet rs = adHoc.executeQuery("SELECT 1");
  59                                 rs.close();
  60                                 lastAction = System.currentTimeMillis();
  61                                 return;
  62                         } catch (SQLException e) {
  63                         }
  64                         statements.clear();
  65                         tryConnect();
  66                 }
  67                 lastAction = System.currentTimeMillis();
  68         }
  69
  70         public static int lastInsertId(PreparedStatement query) throws SQLException {
  71                 ResultSet rs = query.getGeneratedKeys();
  72                 rs.next();
  73                 int id = rs.getInt(1);
  74                 rs.close();
  75                 return id;
  76         }
  77
  78         static ThreadLocal<DatabaseConnection> instances = new ThreadLocal<DatabaseConnection>() {
  79                 @Override
  80                 protected DatabaseConnection initialValue() {
  81                         return new DatabaseConnection();
  82                 }
  83         };
  84
  85         public static DatabaseConnection getInstance() {
  86                 return instances.get();
  87         }
  88
  89         public static boolean isInited() {
  90                 return credentials != null;
  91         }
  92
  93         public static void init(Properties conf) {
  94                 if (credentials != null) {
  95                         throw new Error("Re-initiaizing is forbidden.");
  96                 }
  97                 credentials = conf;
  98         }
  99
 100         public void beginTransaction() throws SQLException {
 101                 c.setAutoCommit(false);
 102         }
 103
 104         public void commitTransaction() throws SQLException {
 105                 c.commit();
 106                 c.setAutoCommit(true);
 107         }
 108
 109         public void quitTransaction() {
 110                 try {
 111                         if (!c.getAutoCommit()) {
 112                                 c.rollback();
 113                                 c.setAutoCommit(true);
 114                         }
 115                 } catch (SQLException e) {
 116                         e.printStackTrace();
 117                 }
 118         }
 119 }