1
0
mirror of https://github.com/postgres/postgres.git synced 2025-07-02 09:02:37 +03:00

This patch merges the identical methods from the JDBC1 and JDBC2

connection implementations (org.postgresql.jdbc[1|2].Connection) into
their superclass (org.postgresql.Connection).

It also changes the close() methods of Connection and PG_Stream, so that
PG_Stream no longer is responsible for sending the termination packet 'X'
to the backend. I figured that protocol-level stuff like that belonged in
Connection more than in PG_Stream.

Anders Bengtsson
This commit is contained in:
Bruce Momjian
2001-07-30 14:51:19 +00:00
parent 462b7d46d1
commit 509f5d241a
4 changed files with 239 additions and 476 deletions

View File

@ -17,7 +17,7 @@ import org.postgresql.largeobject.*;
import org.postgresql.util.*;
/**
* $Id: Connection.java,v 1.6 2001/07/21 18:56:17 momjian Exp $
* $Id: Connection.java,v 1.7 2001/07/30 14:51:19 momjian Exp $
*
* A Connection represents a session with a specific database. Within the
* context of a Connection, SQL statements are executed and results are
@ -100,123 +100,6 @@ public class Connection extends org.postgresql.Connection implements java.sql.Co
// return new CallableStatement(this, sql);
}
/**
* A driver may convert the JDBC sql grammar into its system's
* native SQL grammar prior to sending it; nativeSQL returns the
* native form of the statement that the driver would have sent.
*
* @param sql a SQL statement that may contain one or more '?'
* parameter placeholders
* @return the native form of this statement
* @exception SQLException if a database access error occurs
*/
public String nativeSQL(String sql) throws SQLException
{
return sql;
}
/**
* If a connection is in auto-commit mode, than all its SQL
* statements will be executed and committed as individual
* transactions. Otherwise, its SQL statements are grouped
* into transactions that are terminated by either commit()
* or rollback(). By default, new connections are in auto-
* commit mode. The commit occurs when the statement completes
* or the next execute occurs, whichever comes first. In the
* case of statements returning a ResultSet, the statement
* completes when the last row of the ResultSet has been retrieved
* or the ResultSet has been closed. In advanced cases, a single
* statement may return multiple results as well as output parameter
* values. Here the commit occurs when all results and output param
* values have been retrieved.
*
* @param autoCommit - true enables auto-commit; false disables it
* @exception SQLException if a database access error occurs
*/
public void setAutoCommit(boolean autoCommit) throws SQLException
{
if (this.autoCommit == autoCommit)
return;
if (autoCommit)
ExecSQL("end");
else
ExecSQL("begin");
this.autoCommit = autoCommit;
}
/**
* gets the current auto-commit state
*
* @return Current state of the auto-commit mode
* @exception SQLException (why?)
* @see setAutoCommit
*/
public boolean getAutoCommit() throws SQLException
{
return this.autoCommit;
}
/**
* The method commit() makes all changes made since the previous
* commit/rollback permanent and releases any database locks currently
* held by the Connection. This method should only be used when
* auto-commit has been disabled. (If autoCommit == true, then we
* just return anyhow)
*
* @exception SQLException if a database access error occurs
* @see setAutoCommit
*/
public void commit() throws SQLException
{
if (autoCommit)
return;
ExecSQL("commit");
autoCommit = true;
ExecSQL("begin");
autoCommit = false;
}
/**
* The method rollback() drops all changes made since the previous
* commit/rollback and releases any database locks currently held by
* the Connection.
*
* @exception SQLException if a database access error occurs
* @see commit
*/
public void rollback() throws SQLException
{
if (autoCommit)
return;
ExecSQL("rollback");
autoCommit = true;
ExecSQL("begin");
autoCommit = false;
}
/**
* In some cases, it is desirable to immediately release a Connection's
* database and JDBC resources instead of waiting for them to be
* automatically released (cant think why off the top of my head)
*
* <B>Note:</B> A Connection is automatically closed when it is
* garbage collected. Certain fatal errors also result in a closed
* connection.
*
* @exception SQLException if a database access error occurs
*/
public void close() throws SQLException
{
if (pg_stream != null)
{
try
{
pg_stream.close();
} catch (IOException e) {}
pg_stream = null;
}
}
/**
* Tests to see if a Connection is closed
*
@ -244,112 +127,6 @@ public class Connection extends org.postgresql.Connection implements java.sql.Co
return metadata;
}
/**
* You can put a connection in read-only mode as a hunt to enable
* database optimizations
*
* <B>Note:</B> setReadOnly cannot be called while in the middle
* of a transaction
*
* @param readOnly - true enables read-only mode; false disables it
* @exception SQLException if a database access error occurs
*/
public void setReadOnly (boolean readOnly) throws SQLException
{
this.readOnly = readOnly;
}
/**
* Tests to see if the connection is in Read Only Mode. Note that
* we cannot really put the database in read only mode, but we pretend
* we can by returning the value of the readOnly flag
*
* @return true if the connection is read only
* @exception SQLException if a database access error occurs
*/
public boolean isReadOnly() throws SQLException
{
return readOnly;
}
/**
* You can call this method to try to change the transaction
* isolation level using one of the TRANSACTION_* values.
*
* <B>Note:</B> setTransactionIsolation cannot be called while
* in the middle of a transaction
*
* @param level one of the TRANSACTION_* isolation values with
* the exception of TRANSACTION_NONE; some databases may
* not support other values
* @exception SQLException if a database access error occurs
* @see java.sql.DatabaseMetaData#supportsTransactionIsolationLevel
*/
public void setTransactionIsolation(int level) throws SQLException
{
String q = "SET TRANSACTION ISOLATION LEVEL";
switch(level) {
case java.sql.Connection.TRANSACTION_READ_COMMITTED:
ExecSQL(q + " READ COMMITTED");
return;
case java.sql.Connection.TRANSACTION_SERIALIZABLE:
ExecSQL(q + " SERIALIZABLE");
return;
default:
throw new PSQLException("postgresql.con.isolevel",new Integer(level));
}
}
/**
* Get this Connection's current transaction isolation mode.
*
* @return the current TRANSACTION_* mode value
* @exception SQLException if a database access error occurs
*/
public int getTransactionIsolation() throws SQLException
{
ExecSQL("show xactisolevel");
SQLWarning w = getWarnings();
if (w != null) {
if (w.getMessage().indexOf("READ COMMITTED") != -1) return java.sql.Connection.TRANSACTION_READ_COMMITTED; else
if (w.getMessage().indexOf("READ UNCOMMITTED") != -1) return java.sql.Connection.TRANSACTION_READ_UNCOMMITTED; else
if (w.getMessage().indexOf("REPEATABLE READ") != -1) return java.sql.Connection.TRANSACTION_REPEATABLE_READ; else
if (w.getMessage().indexOf("SERIALIZABLE") != -1) return java.sql.Connection.TRANSACTION_SERIALIZABLE;
}
return java.sql.Connection.TRANSACTION_READ_COMMITTED;
}
/**
* The first warning reported by calls on this Connection is
* returned.
*
* <B>Note:</B> Sebsequent warnings will be changed to this
* SQLWarning
*
* @return the first SQLWarning or null
* @exception SQLException if a database access error occurs
*/
public SQLWarning getWarnings() throws SQLException
{
return firstWarning;
}
/**
* After this call, getWarnings returns null until a new warning
* is reported for this connection.
*
* @exception SQLException if a database access error occurs
*/
public void clearWarnings() throws SQLException
{
firstWarning = null;
}
/**
* This overides the method in org.postgresql.Connection and returns a
* ResultSet.