lazyj
Class DBFunctions.DBConnection

java.lang.Object
  lazyj.DBFunctions.DBConnection

Enclosing class:

DBFunctions

public static final class DBFunctions.DBConnection
extends java.lang.Object

Wrapper around a raw database connection. You cannot create this object directly and you must free the connections properly otherwise you will run in big trouble.

Here is a sample code:

 // set the connection parameters 

 ExtProperties dbProp = new ExtProperties(); 
 dbProp.set("driver", "org.postgresql.Driver"); // mandatory
 dbProp.set("database", "somedb");                              // mandatory
 dbProp.set("host", "127.0.0.1");                                       // defaults to 127.0.0.1 if missing
 dbProp.set("port", "5432");                                            // DB-dependend default if missing
 dbProp.set("user", "username");                                        // recommended
 dbProp.set("password", "*****");                               // recommended
 // you can also set here various other configuration options that the JDBC driver will look at
 
 DBFunctions db = new DBFunctions(dbProp);
 
 DBFunctions.DBConnection conn = db.getConnection();
 
 if (conn==null) return;
 
 Statement stat = null;
 ResultSet rs = null;
 
 try{
      stat = conn.getConnection().createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
      stat.execute(someQuery, Statement.NO_GENERATED_KEYS);
      
      rs = stat.getResultSet();
      
      // ..................
      
      rs.close();
      rs = null;
      
      stat.close();
      stat = null;
 }
 catch (Exception e){ ... }
 finally{
                if (rs!=null){
                        // close
                        try{
                                rs.close();
                        }
                        catch (Exception e){
                        }
                }
                
                if (stat!=null){
                        try{
                                stat.close();
                        }
                        catch (Exception e){
                        }
                }
                
                conn.free();
 }
 

Since:

Jan 17, 2009

Author:

costing

See Also:

DBFunctions.DBFunctions(ExtProperties)

Method Summary

boolean	canUse() Find out if this connection is free to use
void	close() Really close a connection to the database
protected void	finalize() On object deallocation make sure that the connection is properly closed.
boolean	free() Mark a previously used connection as free to be used by somebody else
java.sql.Connection	getConnection() Get the established JDBC connection for direct access to the database.
java.lang.String	getDescription() Get the current description
void	setDescription(java.lang.String description) Set the description to an arbitrary string to be used when debugging a problem.
boolean	use() Use this connection, by marking it as busy and setting the last access time to the current time.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getConnection

public final java.sql.Connection getConnection()

Get the established JDBC connection for direct access to the database.

Returns:

the JDBC connection

canUse

public final boolean canUse()

Find out if this connection is free to use

Returns:

true if free, false if busy or other error

use

public final boolean use()

Use this connection, by marking it as busy and setting the last access time to the current time.

Returns:

true if the connection was free and could be used, false if it was not available

free

public final boolean free()

Mark a previously used connection as free to be used by somebody else

Returns:

true if the connection was in use and was freed, false if the connection was in other state

close

public final void close()

Really close a connection to the database

finalize

protected final void finalize()

On object deallocation make sure that the connection is properly closed.

Overrides:

finalize in class java.lang.Object

setDescription

public void setDescription(java.lang.String description)

Set the description to an arbitrary string to be used when debugging a problem.

Parameters:

description - the description to set

getDescription

public java.lang.String getDescription()

Get the current description

Returns:

the description