org.axonframework.common.jdbc

Class JdbcUtils

java.lang.Object

org.axonframework.common.jdbc.JdbcUtils

public class JdbcUtils
extends Object

Utility class for safely executing Jdbc queries.

Since:

2.2

Author:

Kristian Rosenvold, Allard Buijze, Rene de Waele

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	JdbcUtils.SqlFunction Describes a function that creates a new PreparedStatement ready to be executed.
static interface	JdbcUtils.SqlResultConverter<R> Describes a function that converts a ResultSet into a result of type R.

Method Summary

Modifier and Type	Method and Description
static void	closeQuietly(Connection connection) Close the given connection, if possible.
static void	closeQuietly(ResultSet resultSet) Close the given resultSet, if possible.
static void	closeQuietly(Statement statement) Close the given statement, if possible.
static int[]	executeBatch(Connection connection, JdbcUtils.SqlFunction sqlFunction, Consumer<SQLException> errorHandler) Execute the a batch update or insert statement produced by the given sqlFunction.
static <R> R	executeQuery(Connection connection, JdbcUtils.SqlFunction sqlFunction, JdbcUtils.SqlResultConverter<R> sqlResultConverter, Function<SQLException,RuntimeException> errorHandler) Execute the query given by the sqlFunction.
static int[]	executeUpdates(Connection connection, Consumer<SQLException> errorHandler, JdbcUtils.SqlFunction... sqlFunctions) Execute the update statements produced by the given sqlFunctions.
static <T> T	extract(ResultSet resultSet, int column, Class<T> columnType) Returns the object read from the resultSet, which object can be null, at the given column (base 1).
static <R> JdbcUtils.SqlResultConverter<List<R>>	listResults(JdbcUtils.SqlResultConverter<R> singleResultConverter) Create a converter that produces a List of results of type R from a converter that produces a single result.
static <T> T	nextAndExtract(ResultSet resultSet, int column, Class<T> columnType) Moves the resultSet courser forward and then read the object at the given column (base 1).

Methods inherited from class java.lang.Object

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

Method Detail

executeQuery

public static <R> R executeQuery(Connection connection,
                                 JdbcUtils.SqlFunction sqlFunction,
                                 JdbcUtils.SqlResultConverter<R> sqlResultConverter,
                                 Function<SQLException,RuntimeException> errorHandler)

Execute the query given by the sqlFunction. The ResultSet returned when the query is executed will be converted using the given sqlResultConverter. Any errors will be handled by the given errorHandler.

Type Parameters:

R - the result of the query after conversion

Parameters:

connection - connection to the underlying database that should be used for the query

sqlFunction - the function that returns a PreparedStatement to execute the query against

sqlResultConverter - converts the result set to a value of type R

errorHandler - handles errors as result of executing the query or converting the result set

Returns:

the query result

executeUpdates

public static int[] executeUpdates(Connection connection,
                                   Consumer<SQLException> errorHandler,
                                   JdbcUtils.SqlFunction... sqlFunctions)

Execute the update statements produced by the given sqlFunctions. Any errors will be handled by the given errorHandler.

Parameters:

connection - connection to the underlying database that should be used for the update

errorHandler - handles errors as result of executing the update

sqlFunctions - the functions that produce the update statements

Returns:

an array of update counts containing one element for each sql function

executeBatch

public static int[] executeBatch(Connection connection,
                                 JdbcUtils.SqlFunction sqlFunction,
                                 Consumer<SQLException> errorHandler)

Execute the a batch update or insert statement produced by the given sqlFunction. Any errors will be handled by the given errorHandler.

Parameters:

connection - connection to the underlying database that should be used for the update

sqlFunction - the function that produces the batch update statement

errorHandler - handles errors as result of executing the update

Returns:

an array of update counts containing one element for each sql function

listResults

public static <R> JdbcUtils.SqlResultConverter<List<R>> listResults(JdbcUtils.SqlResultConverter<R> singleResultConverter)

Create a converter that produces a List of results of type R from a converter that produces a single result. The returned converter iterates over the resultSet until all results have been converted and added to the list.

Type Parameters:

R - the type of result produced by the singleResultConverter

Parameters:

singleResultConverter - the converter that can convert a single result from the current position of the resultSet

Returns:

converter that produces a list of results

closeQuietly

public static void closeQuietly(ResultSet resultSet)

Close the given resultSet, if possible. All exceptions are discarded.

Parameters:

resultSet - The resource to close. May be null.

closeQuietly

public static void closeQuietly(Statement statement)

Close the given statement, if possible. All exceptions are discarded.

Parameters:

statement - The resource to close. May be null.

closeQuietly

public static void closeQuietly(Connection connection)

Close the given connection, if possible. All exceptions are discarded.

Parameters:

connection - The resource to close. May be null.

nextAndExtract

public static <T> T nextAndExtract(ResultSet resultSet,
                                   int column,
                                   Class<T> columnType)
                            throws SQLException,
                                   NullPointerException

Moves the resultSet courser forward and then read the object at the given column (base 1). Please note that this method changes the resultSet cursor position. If the resultSet reaches the end, this method returns null. This method reads the object at the given column (base 1), which object can be null as well.

Please use the method extract(ResultSet, int, Class) if you do not need to move the resultSet cursor.

This method makes use of the ResultSet.wasNull() method to verify whether the object that was read was null or not. There are cases where the database driver (such as MySQL) returns the default primitive value instead of null. This method avoids this problem.

Parameters:

resultSet - The ResultSet to extract data from

column - The index of the column containing to read

columnType - The expected type of data in the column

Returns:

The next value in the specified column or null if no data was present

Throws:

SQLException - if an error occurs while reading the object

NullPointerException - if the resultSet or columnType are null

See Also:

extract(ResultSet, int, Class)

extract

public static <T> T extract(ResultSet resultSet,
                            int column,
                            Class<T> columnType)
                     throws SQLException,
                            NullPointerException

Returns the object read from the resultSet, which object can be null, at the given column (base 1).

This method makes use of the ResultSet.wasNull() method to verify whether the object that was read was null or not. There are cases where the database driver (such as MySQL) returns the default primitive value instead of null. This method avoids this problem.

Parameters:

resultSet - the result set from where the object is read (which cannot be null)

column - the column index (which starts from 1)

columnType - the object type (which cannot be null)

Returns:

the object read from the resultSet, which object can be null, at the given column (base 1).

Throws:

SQLException - if an error occurs while reading the object

NullPointerException - if the resultSet or columnType are null