File	Doc	Category	Size	Date	Package
MsqlConnection.java	API Doc	Example	10297	Tue Jan 01 00:00:00 GMT 1980	COM.imaginary.sql.msql

MsqlConnection

• java.lang.Object

Fields Summary
private String	catalog
private boolean	connecting
private Socket	connection
private Statement	current
private MsqlInputStream	input
private int	isolation
private MsqlOutputStream	output
private String	user
private int	version
private SQLWarning	warnings

Constructors Summary
MsqlConnection(String host, int port, String db, Properties p) // Since this should only be instantiated by MsqlDriver, this is // package visibility super(); user = (String)p.get("user"); if( user == null || user.equals("") ) { user = "nobody"; } connect(host, port, user); selectDatabase(db); synchronized( this ) { connecting = false; notify(); }

Methods Summary
private void	awaitConnection() synchronized( this ) { while( connecting ) { try { wait(); } catch( InterruptedException e ) { if( connecting ) { throw new MsqlException(e); } } } }
private void	cleanConnection() synchronized( this ) { if( current != null ) { try { current.close(); } catch( SQLException e ) { e.printStackTrace(); } current = null; } connecting = false; connection = null; } input = null; output = null; user = null;
public synchronized void	clearWarnings() Sets the SQLWarning chain to null. exception java.sql.SQLException never thrown warnings = null;
public synchronized void	close() Closes this database connection. It will also close any associated Statement instance. exception java.sql.SQLException thrown if problems occur Exception except = null; awaitConnection(); if( isClosed() ) { throw new SQLException("This Connection is already closed."); } // Any current statement has ownership of the streams // We therefore have to close *before* sending data if( current != null ) { current.close(); current = null; } // Let mSQL know we are closing down and close the output stream try { output.writeAsciiString("1"); output.flush(); output.close(); output = null; } catch( IOException e ) { output = null; except = e; } // close the input stream try { input.close(); input = null; } catch( IOException e ) { input = null; except = e; } // close the connection try { connection.close(); } catch( IOException e ) { connection = null; throw new MsqlException(e); } if( except != null ) { throw new MsqlException(except); }
public void	commit() This is a NO-OP for mSQL. All statements are always auto-committed. exception java.sql.SQLException never thrown
private void	connect(java.lang.String host, int port, java.lang.String user) try { String tmp; connection = new Socket(host, port); input = new MsqlInputStream(connection.getInputStream()); output = new MsqlOutputStream(connection.getOutputStream()); tmp = input.readAsciiString(); // Check for mSQL version if( tmp.startsWith("0:22:") ) { version = 2; // version 2.0 } else if( tmp.startsWith("0:6:") ) { version = 1; // version 1.0.x } else { throw new SQLException("Unsupported mSQL version."); } // Check if user was validated output.writeAsciiString(user); tmp = input.readAsciiString(); if( !tmp.startsWith("-100:") ) { throw new SQLException("Access to server denied."); } } catch( IOException e ) { cleanConnection(); throw new SQLException("Connection failed."); }
public java.sql.Statement	createStatement() This JDBC method creates an instance of MsqlStatement and returns it. If there are currently any open MsqlStatement's, it will close them. Not that mSQL does not provide a way to interrupt executing statements, so it has to wait for any pending statements to finish before closing them. return a new MsqlStatement instance exception java.sql.SQLException an error occurred in creating the Statement instance, likely raised by the constructor awaitConnection(); synchronized( this ) { if( current != null ) { try { current.close(); } catch( SQLException e ) { e.printStackTrace(); } } current = new MsqlStatement(this, input, output); return current; }
public boolean	getAutoCommit() This method always returns true since mSQL is always in auto-commit mode. return true--always exception java.sql.SQLException never thrown return true;
public synchronized java.lang.String	getCatalog() Provides the catalog name. mSQL does not support catalogs, however. exception java.sql.SQLException never thrown return catalog;
public java.sql.DatabaseMetaData	getMetaData() This method is not yet implemented. return null;
public synchronized int	getTransactionIsolation() return the transaction isolation, not supported by mSQL exception java.sql.SQLException never thrown return isolation;
public java.lang.String	getUser() return the user name used for this Connection exception java.sql.SQLException thrown if the connection is never made awaitConnection(); return user;
public synchronized java.sql.SQLWarning	getWarnings() return the SQLWarning chain for this Connection exception java.sql.SQLException never thrown return warnings;
public synchronized boolean	isClosed() return true if this Connection has been closed exception java.sql.SQLException never thrown awaitConnection(); return (connection == null);
public boolean	isReadOnly() return false--always return false;
public java.lang.String	nativeSQL(java.lang.String sql) This gives the driver an opportunity to turn JDBC compliant SQL into mSQL specific SQL. My feeling is why bother. exception java.sql.SQLException never thrown return sql;
public java.sql.CallableStatement	prepareCall(java.lang.String sql) Callable statements are not supported by mSQL. This will therefore always throw an exception. throw new SQLException("mSQL does not support stored procedures.");
public java.sql.PreparedStatement	prepareStatement(java.lang.String sql) Prepared statements are not supported by mSQL. This will therefore always throw an exception. throw new SQLException("mSQL does not support prepared statements.");
public void	rollback() This method always errors since you cannot rollback an mSQL transaction. throw new SQLException("mSQL exception: mSQL does not support " + "rollbacks.");
private void	selectDatabase(java.lang.String database) String tmp; try { output.writeAsciiString("2 " + database); tmp = input.readAsciiString(); if( tmp.startsWith("-1:") ) { throw new MsqlException(tmp); } } catch( IOException e ) { cleanConnection(); throw new MsqlException(e); }
public void	setAutoCommit(boolean b) This method will thrown an exception if you try to turn auto-commit off since JDBC does not support transactional logic. param b should always be true exception java.sql.SQLException thrown if the param is false if( b ) { return; } throw new SQLException("mSQL must always be auto-commit = true.");
public synchronized void	setCatalog(java.lang.String str) Sets the catalog name for this connection. mSQL does not support catalogs, so this method is a NO-OP. exception java.sql.SQLException never thrown catalog = str;
public void	setReadOnly(boolean b) mSQL does not support read-only mode. exception java.sql.SQLException alway thrown throw new SQLException("mSQL does not support read-only mode.");
public synchronized void	setTransactionIsolation(int x) This is not supported by mSQL, thus this is a NO-OP. exception java.sql.SQLException never thrown isolation = x;