org.rhq.plugins.database

Class DatabasePluginUtil

java.lang.Object

org.rhq.plugins.database.DatabasePluginUtil

public class DatabasePluginUtil
extends Object

Author:

Thomas Segismont

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DatabasePluginUtil.ComponentCannotProvideConnectionException

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	canProvideConnection(ResourceComponent component)
static Connection	getConnectionFromComponent(ResourceComponent component) Gets a Connection from the component.
static List<Map<String,Object>>	getGridValues(ResourceComponent component, String query, Object... parameters) Returns a list of values, one per row, containing a map of column names to values of that row.
static Map<String,Double>	getNumericQueryValueMap(ResourceComponent component, String query, Object... parameters) Returns a mapping of rows as key-value pairs where the key is the first column (a string) and the second column is a value numeric.
static Map<String,Double>	getNumericQueryValues(ResourceComponent component, String query, Object... parameters) Executes a query, returning the results as a map where the keys are the column names and values are the value of that column.
static Double	getSingleNumericQueryValue(ResourceComponent component, String query, Object... parameters) Returns the result of a query as a single Double value.
static boolean	hasConnectionPoolingSupport(ResourceComponent component) Determines if a resource component supports connection pooling.
static void	safeClose(Connection connection)
static void	safeClose(Connection connection, Statement statement)
static void	safeClose(Connection connection, Statement statement, ResultSet resultSet)
static void	safeClose(ResultSet resultSet)
static void	safeClose(Statement statement)

Methods inherited from class java.lang.Object

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

Method Detail

canProvideConnection

public static boolean canProvideConnection(ResourceComponent component)

Returns:

false unless component is not null and supports connection pooling or is an instance of DatabaseComponent.

hasConnectionPoolingSupport

public static boolean hasConnectionPoolingSupport(ResourceComponent component)

Determines if a resource component supports connection pooling.

Parameters:

component - the resource component

Returns:

false unless component is not null, implements ConnectionPoolingSupport and a call to ConnectionPoolingSupport.supportsConnectionPooling() returns true.

getConnectionFromComponent

public static Connection getConnectionFromComponent(ResourceComponent component)
                                             throws SQLException

Gets a Connection from the component.

Parameters:

component - a resource component that must be able to provide a Connection.

Throws:

SQLException - if component supports connection pooling and a pooled connection could not be retrieved.

IllegalArgumentException - if resource component is null or cannot provide a Connection (does not support connection pooling and does not implement DatabaseComponent).

getNumericQueryValues

public static Map<String,Double> getNumericQueryValues(ResourceComponent component,
                                       String query,
                                       Object... parameters)

Executes a query, returning the results as a map where the keys are the column names and values are the value of that column. Note that depending on the database, the column names may be uppercase (Oracle) or lowercase.

Parameters:

component -

query - SQL query string

parameters - optional bind parameters

Returns:

a map of query results

getNumericQueryValueMap

public static Map<String,Double> getNumericQueryValueMap(ResourceComponent component,
                                         String query,
                                         Object... parameters)

Returns a mapping of rows as key-value pairs where the key is the first column (a string) and the second column is a value numeric.

Parameters:

component - the component to execute on

query - the sql query to run

parameters - any parameters to bind first

Returns:

a Map of the keys against the value

getSingleNumericQueryValue

public static Double getSingleNumericQueryValue(ResourceComponent component,
                                String query,
                                Object... parameters)

Returns the result of a query as a single Double value. Returns Double.NaN if the query fails.

getGridValues

public static List<Map<String,Object>> getGridValues(ResourceComponent component,
                                     String query,
                                     Object... parameters)
                                              throws SQLException

Returns a list of values, one per row, containing a map of column names to values of that row. Note depending on the database, the column names may be uppercase (Oracle) or lowercase.

Parameters:

component - database to query

query - SQL query

parameters - parameters to bind to the query

Throws:

SQLException - if query fails

safeClose

public static void safeClose(Connection connection)

safeClose

public static void safeClose(Connection connection,
             Statement statement)

safeClose

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

safeClose

public static void safeClose(Statement statement)

safeClose

public static void safeClose(ResultSet resultSet)