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.sql.Statement;
   9 import java.util.HashMap;
  10 import java.util.Properties;
  11
  12 public class DatabaseConnection {
  13
  14     public static final int CONNECTION_TIMEOUT = 24 * 60 * 60;
  15
  16     private Connection c;
  17
  18     private HashMap<String, GigiPreparedStatement> statements = new HashMap<String, GigiPreparedStatement>();
  19
  20     private static Properties credentials;
  21
  22     private Statement adHoc;
  23
  24     public DatabaseConnection() {
  25         try {
  26             Class.forName(credentials.getProperty("sql.driver"));
  27         } catch (ClassNotFoundException e) {
  28             e.printStackTrace();
  29         }
  30         tryConnect();
  31
  32     }
  33
  34     private void tryConnect() {
  35         try {
  36             c = DriverManager.getConnection(credentials.getProperty("sql.url") + "?zeroDateTimeBehavior=convertToNull", credentials.getProperty("sql.user"), credentials.getProperty("sql.password"));
  37             PreparedStatement ps = c.prepareStatement("SET SESSION wait_timeout=?, time_zone='+0:00';");
  38             ps.setInt(1, CONNECTION_TIMEOUT);
  39             ps.execute();
  40             ps.close();
  41             adHoc = c.createStatement();
  42         } catch (SQLException e) {
  43             e.printStackTrace();
  44         }
  45     }
  46
  47     public GigiPreparedStatement prepare(String query) {
  48         ensureOpen();
  49         GigiPreparedStatement statement = statements.get(query);
  50         if (statement == null) {
  51             try {
  52                 statement = new GigiPreparedStatement(c.prepareStatement(query, Statement.RETURN_GENERATED_KEYS));
  53             } catch (SQLException e) {
  54                 throw new Error(e);
  55             }
  56             statements.put(query, statement);
  57         }
  58         return statement;
  59     }
  60
  61     private long lastAction = System.currentTimeMillis();
  62
  63     private void ensureOpen() {
  64         if (System.currentTimeMillis() - lastAction > CONNECTION_TIMEOUT * 1000L) {
  65             try {
  66                 ResultSet rs = adHoc.executeQuery("SELECT 1");
  67                 rs.close();
  68                 lastAction = System.currentTimeMillis();
  69                 return;
  70             } catch (SQLException e) {
  71             }
  72             statements.clear();
  73             tryConnect();
  74         }
  75         lastAction = System.currentTimeMillis();
  76     }
  77
  78     private static ThreadLocal<DatabaseConnection> instances = new ThreadLocal<DatabaseConnection>() {
  79
  80         @Override
  81         protected DatabaseConnection initialValue() {
  82             return new DatabaseConnection();
  83         }
  84     };
  85
  86     public static DatabaseConnection getInstance() {
  87         return instances.get();
  88     }
  89
  90     public static boolean isInited() {
  91         return credentials != null;
  92     }
  93
  94     public static void init(Properties conf) {
  95         if (credentials != null) {
  96             throw new Error("Re-initiaizing is forbidden.");
  97         }
  98         credentials = conf;
  99     }
 100
 101     public void beginTransaction() throws SQLException {
 102         c.setAutoCommit(false);
 103     }
 104
 105     public void commitTransaction() throws SQLException {
 106         c.commit();
 107         c.setAutoCommit(true);
 108     }
 109
 110     public void quitTransaction() {
 111         try {
 112             if ( !c.getAutoCommit()) {
 113                 c.rollback();
 114                 c.setAutoCommit(true);
 115             }
 116         } catch (SQLException e) {
 117             e.printStackTrace();
 118         }
 119     }
 120 }