org.josef.jdbc

Class JdbcUtil

java.lang.Object

org.josef.jdbc.JdbcUtil

@Status(stage=PRODUCTION,
        unitTests=COMPLETE)
 @Reviews(value=@Review(by="Kees Schotanus",at="2009-04-11"))
public final class JdbcUtil
extends Object

JDBC Utility class.

Version:

1.1 $Revision: 6483 $

Author:

Kees Schotanus

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_LITERALS_IN_IN_CLAUSE The maximum number of literals that may appear in an in clause.

Method Summary

Modifier and Type	Method and Description
static void	close(ResultSet resultSet, Statement statement, Connection connection) Closes the supplied resultSet, statement and connection.
static String	encode(String parameter) Simple encode method that encodes a SQL parameter to prevent SQL injection.
static Connection	getConnection() Gets a database connection from the database that is configured in GlobalSettings.
static <T> List<T>	getEntitiesByColumnCriteria(DataSource dataSource, String tableNames, String matchingColumnName, String columnNames, String orderByColumnNames, Boolean descending, ResultSetRowCallBackInterface<T> callBackInterface, Integer maxEntities, List<?> criteria) Retrieves entities from a database table with the supplied name, based on a supplied collection of criteria that are to match a supplied column of the table using an SQL in clause. In short this method allows you to execute statements like: SELECT COL1,COL2,COL3 FROM TABLE1,TABLE2 WHERE COL4 IN (1,2,3); Normally you only want to use this method when the number of criteria (the 1,2,3 in the example above) is very large and can't be selected with an IN (SELECT ...).

Methods inherited from class java.lang.Object

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

Field Detail

MAX_LITERALS_IN_IN_CLAUSE

public static final int MAX_LITERALS_IN_IN_CLAUSE

The maximum number of literals that may appear in an in clause. The problem with this constant is that different database servers may support a different number of literals!

See Also:

Constant Field Values

Method Detail

getConnection

public static Connection getConnection()
                                throws SQLException

Gets a database connection from the database that is configured in GlobalSettings.

Returns:

A database connection from the database that is configured in GlobalSettings.

Throws:

SQLException - When no connection could be obtained.

close

public static void close(ResultSet resultSet,
                         Statement statement,
                         Connection connection)

Closes the supplied resultSet, statement and connection.
A resource that could not be closed is logged as a warning.

Parameters:

resultSet - The resultSet to close or null.

statement - The statement to close or null.

connection - The connection to close or null.

encode

public static String encode(String parameter)

Simple encode method that encodes a SQL parameter to prevent SQL injection.

Parameters:

parameter - The parameter to encode.

Returns:

The encoded parameter value.
When the supplied parameter is null or empty, it will be returned as-is.

getEntitiesByColumnCriteria

public static <T> List<T> getEntitiesByColumnCriteria(DataSource dataSource,
                                                      String tableNames,
                                                      String matchingColumnName,
                                                      String columnNames,
                                                      String orderByColumnNames,
                                                      Boolean descending,
                                                      ResultSetRowCallBackInterface<T> callBackInterface,
                                                      Integer maxEntities,
                                                      List<?> criteria)
                                               throws SQLException

Retrieves entities from a database table with the supplied name, based on a supplied collection of criteria that are to match a supplied column of the table using an SQL in clause.
In short this method allows you to execute statements like:
SELECT COL1,COL2,COL3 FROM TABLE1,TABLE2 WHERE COL4 IN (1,2,3);
Normally you only want to use this method when the number of criteria (the 1,2,3 in the example above) is very large and can't be selected with an IN (SELECT ...). Oracle for example can handle about a 1000 literals in the in clause but this method can handle many more since it breaks up the criteria and executes a SQL statement for every sublist of criteria.

Type Parameters:

T - Type of the elements in the ResultSetRowCallBackInterface.

Parameters:

dataSource - The datasource to execute the query.

tableNames - The names of the tables separated with a comma or a single table name.
Table names may include a schema name.

matchingColumnName - The name of the column to match the criteria against.

columnNames - Comma separated list of column names to retrieve.

orderByColumnNames - The names of the order by columns separated with a comma or a single column name.
Column names may be qualified with a table name.

descending - True for descending, false or null for ascending.

callBackInterface - the ResultSetRowCallBackInterface to run to actually get the entities.

maxEntities - the maximum number of entities to return, or null for an unlimited number of entities.

criteria - List of criteria to match against the supplied matchingColumnNames of the entities to retrieve.
None of the criteria can be null (but this is not checked here).

Returns:

A List of objects as constructed by the supplied callBackInterface.

Throws:

IllegalArgumentException - When either the supplied tableNames, matchingColumnName, columnNames or criteria is empty.

NullPointerException - When either the supplied dataSource, tableNames, matchingColumnName, columnNames, callBackInterface or criteria is null.

SQLException - When the statement could not be executed.