Changeset 318 for trunk/org.bridgedb.rdb/src/org/bridgedb/rdb/SimpleGdb.java

Timestamp:

02/25/10 20:57:43 (2 years ago)

Author:

martijn

Message:

Made SimpleGdb? thread-safe. Instantiate with con-
nection string instead of connection object, to allow
future implementation of thread pooling

Files:

• trunk/org.bridgedb.rdb/src/org/bridgedb/rdb/SimpleGdb.java (modified) (7 diffs)

trunk/org.bridgedb.rdb/src/org/bridgedb/rdb/SimpleGdb.java

@@ -18 +18 @@
 
 import java.sql.Connection;
+import java.sql.DriverManager;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
@@ -52 +53 @@
 public abstract class SimpleGdb extends IDMapperRdb
 {
+        private final String connectionString;
         /**
          * Create IDMapper based on an existing SQL connection.
          * @param con Existing SQL Connection.
          */
-        SimpleGdb(Connection con)
-        {
-                this.con = con;
-        }
-        
-        private boolean keepConnection = true;
-
+        SimpleGdb(String dbName, String connectionString)
+        {
+                this.connectionString = connectionString;
+                this.dbName = dbName;
+        }
+
+        private boolean singleConnection = true;
+        private boolean neverCloseConnection = true;
+        
         /**
          * helper class that handles the life cycle of a connection, query and resultset.
@@ -160 +164 @@
                         inited = false;
                         if (rs != null) try { rs.close(); } catch (SQLException ignore) {}
-                        if (keepConnection) return;
+                        if (neverCloseConnection) return;
                         if (pst != null) try { pst.close(); } catch (SQLException ignore) {}
+                        pst = null;
                         if (con != null) try { con.close(); } catch (SQLException ignore) {}
-                }
-        }
-        
-        protected Connection getConnection() throws SQLException
-        {
+                        con = null;
+                }
+        }
+
+        private Connection con = null;
+        
+        synchronized public Connection getConnection() throws SQLException
+        {
+                // if singleConnection is true, each call to getConnection() will return the same object.
+                // if singleConnection is false, each call to getConneciton() will lead to a new connection object being created.
+                if (!singleConnection || con == null)
+                {
+                        con = DriverManager.getConnection(connectionString); 
+                        con.setReadOnly(true);
+                }
                 return con;
         }
@@ -174 +189 @@
          * The {@link Connection} to the Gene Database.
          */
-        protected Connection con = null;
+        
+        //private Connection con = null;
 
         /** {@inheritDoc} */
-        final public boolean isConnected() { return con != null; }
-
-        protected String dbName;
+        final public boolean isConnected() { 
+                //return con != null; 
+                return true;
+        }
+
+        protected final String dbName;
         
         /** {@inheritDoc} */
@@ -187 +206 @@
         final public void close() throws IDMapperException 
         {
-                if (con == null) throw new IDMapperException("Database connection already closed");
-                try
-                {
-                        con.close();
-                }
-                catch (SQLException ex)
-                {
-                        throw new IDMapperException (ex);
-                }
-                con = null;
+//              try
+//              {
+//                      con.close();
+//              }
+//              catch (SQLException ex)
+//              {
+//                      throw new IDMapperException (ex);
+//              }
+//              con = null;
         }
         
@@ -212 +230 @@
                 try
                 {
-                        ResultSet r = con.createStatement().executeQuery("SELECT COUNT(*) FROM " + "datanode");
+                        ResultSet r = getConnection().createStatement().executeQuery("SELECT COUNT(*) FROM " + "datanode");
                         r.next();
                         result = r.getInt (1);
@@ -234 +252 @@
                 try
                 {
-                        ResultSet r = con.createStatement().executeQuery(
+                        ResultSet r = getConnection().createStatement().executeQuery(
                                         "SELECT COUNT(*) FROM datanode WHERE code = '" + ds.getSystemCode() + "'");
                         r.next();