org.jivesoftware.database
Class DbConnectionManager

java.lang.Object
  org.jivesoftware.database.DbConnectionManager

public class DbConnectionManager
extends Object

Central manager of database connections. All methods are static so that they can be easily accessed throughout the classes in the database package.

This class also provides a set of utility methods that abstract out operations that may not work on all databases such as setting the max number or rows that a query should return.

Author:

Jive Software

See Also:

ConnectionProvider

Nested Class Summary

static class

DbConnectionManager.DatabaseType A class that identifies the type of the database that Jive is connected to.

Method Summary

static void	closeConnection(Connection con) Closes a database connection (returning the connection to the connection pool).
static void	closeConnection(ResultSet rs, Statement stmt, Connection con) Closes a result set, statement and database connection (returning the connection to the connection pool).
static void	closeConnection(Statement stmt, Connection con) Closes a statement and database connection (returning the connection to the connection pool).
static void	closeResultSet(ResultSet rs) Closes a result set.
static void	closeStatement(Statement stmt) Closes a statement.
static void	closeTransactionConnection(Connection con, boolean abortTransaction) Closes a Connection.
static void	closeTransactionConnection(PreparedStatement pstmt, Connection con, boolean abortTransaction) Closes a PreparedStatement and Connection.
static PreparedStatement	createScrollablePreparedStatement(Connection con, String sql) Creates a scroll insensitive PreparedStatement if the JDBC driver supports it, or a normal PreparedStatement otherwise.
static Statement	createScrollableStatement(Connection con) Creates a scroll insensitive Statement if the JDBC driver supports it, or a normal Statement otherwise.
static void	destroyConnectionProvider() Destroys the currennt connection provider.
static Connection	getConnection() Returns a database connection from the currently active connection provider.
static ConnectionProvider	getConnectionProvider() Returns the current connection provider.
static DbConnectionManager.DatabaseType	getDatabaseType() Returns the database type.
static String	getLargeTextField(ResultSet rs, int columnIndex) Retrives a large text column from a result set, automatically performing streaming if the JDBC driver requires it.
static SchemaManager	getSchemaManager() Returns a SchemaManager instance, which can be used to manage the database schema information for Wildfire and plugins.
static Connection	getTransactionConnection() Returns a Connection from the currently active connection provider that is ready to participate in transactions (auto commit is set to false).
static boolean	isBatchUpdatesSupported()
static boolean	isFetchSizeSupported()
static boolean	isMaxRowsSupported()
static boolean	isProfilingEnabled() Returns true if connection profiling is turned on.
static boolean	isScrollResultsSupported()
static boolean	isStreamTextRequired()
static boolean	isSubqueriesSupported()
static boolean	isTransactionsSupported()
static void	scrollResultSet(ResultSet rs, int rowNumber) Scrolls forward in a result set the specified number of rows.
static void	setConnectionProvider(ConnectionProvider provider) Sets the connection provider.
static void	setFetchSize(ResultSet rs, int fetchSize) Sets the number of rows that the JDBC driver should buffer at a time.
static void	setLargeTextField(PreparedStatement pstmt, int parameterIndex, String value) Sets a large text column in a result set, automatically performing streaming if the JDBC driver requires it.
static void	setMaxRows(Statement stmt, int maxRows) Sets the max number of rows that should be returned from executing a statement.
static void	setProfilingEnabled(boolean enable) Turns connection profiling on or off.

Methods inherited from class java.lang.Object

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

Method Detail

getConnection

public static Connection getConnection()
                                throws SQLException

Returns a database connection from the currently active connection provider. (auto commit is set to true).

Returns:

a connection.

Throws:

SQLException - if a SQL exception occurs.

getTransactionConnection

public static Connection getTransactionConnection()
                                           throws SQLException

Returns a Connection from the currently active connection provider that is ready to participate in transactions (auto commit is set to false).

Returns:

a connection with transactions enabled.

Throws:

SQLException - if a SQL exception occurs.

closeTransactionConnection

public static void closeTransactionConnection(PreparedStatement pstmt,
                                              Connection con,
                                              boolean abortTransaction)

Closes a PreparedStatement and Connection. However, it first rolls back the transaction or commits it depending on the value of abortTransaction.

Parameters:

pstmt - the prepared statement to close.

con - the connection to close.

abortTransaction - true if the transaction should be rolled back.

closeTransactionConnection

public static void closeTransactionConnection(Connection con,
                                              boolean abortTransaction)

Closes a Connection. However, it first rolls back the transaction or commits it depending on the value of abortTransaction.

Parameters:

con - the connection to close.

abortTransaction - true if the transaction should be rolled back.

closeResultSet

public static void closeResultSet(ResultSet rs)

Closes a result set. This method should be called within the finally section of your database logic, as in the following example:

  public void doSomething(Connection con) {
      ResultSet rs = null;
      PreparedStatement pstmt = null;
      try {
          pstmt = con.prepareStatement("select * from blah");
          rs = pstmt.executeQuery();
          ....
      }
      catch (SQLException sqle) {
          Log.error(sqle);
      }
      finally {
          ConnectionManager.closeResultSet(rs);
          ConnectionManager.closePreparedStatement(pstmt);
      }
 } 

Parameters:

rs - the result set to close.

closeStatement

public static void closeStatement(Statement stmt)

Closes a statement. This method should be called within the finally section of your database logic, as in the following example:

  public void doSomething(Connection con) {
      PreparedStatement pstmt = null;
      try {
          pstmt = con.prepareStatement("select * from blah");
          ....
      }
      catch (SQLException sqle) {
          Log.error(sqle);
      }
      finally {
          ConnectionManager.closePreparedStatement(pstmt);
      }
 } 

Parameters:

stmt - the statement.

closeConnection

public static void closeConnection(ResultSet rs,
                                   Statement stmt,
                                   Connection con)

Closes a result set, statement and database connection (returning the connection to the connection pool). This method should be called within the finally section of your database logic, as in the following example:

 Connection con = null;
 PrepatedStatment pstmt = null;
 ResultSet rs = null;
 try {
     con = ConnectionManager.getConnection();
     pstmt = con.prepareStatement("select * from blah");
     rs = psmt.executeQuery();
     ....
 }
 catch (SQLException sqle) {
     Log.error(sqle);
 }
 finally {
     ConnectionManager.closeConnection(rs, pstmt, con);
 }

Parameters:

rs - the result set.

stmt - the statement.

con - the connection.

closeConnection

public static void closeConnection(Statement stmt,
                                   Connection con)

Closes a statement and database connection (returning the connection to the connection pool). This method should be called within the finally section of your database logic, as in the following example:

 Connection con = null;
 PrepatedStatment pstmt = null;
 try {
     con = ConnectionManager.getConnection();
     pstmt = con.prepareStatement("select * from blah");
     ....
 }
 catch (SQLException sqle) {
     Log.error(sqle);
 }
 finally {
     DbConnectionManager.closeConnection(pstmt, con);
 }

Parameters:

stmt - the statement.

con - the connection.

closeConnection

public static void closeConnection(Connection con)

Closes a database connection (returning the connection to the connection pool). Any statements associated with the connection should be closed before calling this method. This method should be called within the finally section of your database logic, as in the following example:

 Connection con = null;
 try {
     con = ConnectionManager.getConnection();
     ....
 }
 catch (SQLException sqle) {
     Log.error(sqle);
 }
 finally {
     DbConnectionManager.closeConnection(con);
 }

Parameters:

con - the connection.

createScrollableStatement

public static Statement createScrollableStatement(Connection con)
                                           throws SQLException

Creates a scroll insensitive Statement if the JDBC driver supports it, or a normal Statement otherwise.

Parameters:

con - the database connection.

Returns:

a Statement

Throws:

SQLException - if an error occurs.

createScrollablePreparedStatement

public static PreparedStatement createScrollablePreparedStatement(Connection con,
                                                                  String sql)
                                                           throws SQLException

Creates a scroll insensitive PreparedStatement if the JDBC driver supports it, or a normal PreparedStatement otherwise.

Parameters:

con - the database connection.

sql - the SQL to create the PreparedStatement with.

Returns:

a PreparedStatement

Throws:

SQLException - if an error occurs.

scrollResultSet

public static void scrollResultSet(ResultSet rs,
                                   int rowNumber)
                            throws SQLException

Scrolls forward in a result set the specified number of rows. If the JDBC driver supports the feature, the cursor will be moved directly. Otherwise, we scroll through results one by one manually by calling rs.next().

Parameters:

rs - the ResultSet object to scroll.

rowNumber - the row number to scroll forward to.

Throws:

SQLException - if an error occurs.

getConnectionProvider

public static ConnectionProvider getConnectionProvider()

Returns the current connection provider. The only case in which this method should be called is if more information about the current connection provider is needed. Database connections should always be obtained by calling the getConnection method of this class.

Returns:

the connection provider.

setConnectionProvider

public static void setConnectionProvider(ConnectionProvider provider)

Sets the connection provider. The old provider (if it exists) is shut down before the new one is started. A connection provider should not be started before being passed to the connection manager because the manager will call the start() method automatically.

Parameters:

provider - the ConnectionProvider that the manager should obtain connections from.

destroyConnectionProvider

public static void destroyConnectionProvider()

Destroys the currennt connection provider. Future calls to getConnectionProvider() will return null until a new ConnectionProvider is set, or one is automatically loaded by a call to getConnection().

getLargeTextField

public static String getLargeTextField(ResultSet rs,
                                       int columnIndex)
                                throws SQLException

Retrives a large text column from a result set, automatically performing streaming if the JDBC driver requires it. This is necessary because different JDBC drivers have different capabilities and methods for retrieving large text values.

Parameters:

rs - the ResultSet to retrieve the text field from.

columnIndex - the column in the ResultSet of the text field.

Returns:

the String value of the text field.

Throws:

SQLException - if an SQL exception occurs.

setLargeTextField

public static void setLargeTextField(PreparedStatement pstmt,
                                     int parameterIndex,
                                     String value)
                              throws SQLException

Sets a large text column in a result set, automatically performing streaming if the JDBC driver requires it. This is necessary because different JDBC drivers have different capabilities and methods for setting large text values.

Parameters:

pstmt - the PreparedStatement to set the text field in.

parameterIndex - the index corresponding to the text field.

value - the String to set.

Throws:

SQLException - if an SQL exception occurs.

setMaxRows

public static void setMaxRows(Statement stmt,
                              int maxRows)

Sets the max number of rows that should be returned from executing a statement. The operation is automatically bypassed if Jive knows that the the JDBC driver or database doesn't support it.

Parameters:

stmt - the Statement to set the max number of rows for.

maxRows - the max number of rows to return.

setFetchSize

public static void setFetchSize(ResultSet rs,
                                int fetchSize)

Sets the number of rows that the JDBC driver should buffer at a time. The operation is automatically bypassed if Jive knows that the the JDBC driver or database doesn't support it.

Parameters:

rs - the ResultSet to set the fetch size for.

fetchSize - the fetchSize.

getSchemaManager

public static SchemaManager getSchemaManager()

Returns a SchemaManager instance, which can be used to manage the database schema information for Wildfire and plugins.

Returns:

a SchemaManager instance.

getDatabaseType

public static DbConnectionManager.DatabaseType getDatabaseType()

Returns the database type. The possible types are constants of the DatabaseType class. Any database that doesn't have its own constant falls into the "Other" category.

Returns:

the database type.

isProfilingEnabled

public static boolean isProfilingEnabled()

Returns true if connection profiling is turned on. You can collect profiling statistics by using the static methods of the ProfiledConnection class.

Returns:

true if connection profiling is enabled.

setProfilingEnabled

public static void setProfilingEnabled(boolean enable)

Turns connection profiling on or off. You can collect profiling statistics by using the static methods of the ProfiledConnection class.

Parameters:

enable - true to enable profiling; false to disable.

isTransactionsSupported

public static boolean isTransactionsSupported()

isStreamTextRequired

public static boolean isStreamTextRequired()

isMaxRowsSupported

public static boolean isMaxRowsSupported()

isFetchSizeSupported

public static boolean isFetchSizeSupported()

isSubqueriesSupported

public static boolean isSubqueriesSupported()

isScrollResultsSupported

public static boolean isScrollResultsSupported()

isBatchUpdatesSupported

public static boolean isBatchUpdatesSupported()