sirius.db.jdbc

Class Databases

java.lang.Object

sirius.db.jdbc.Databases

All Implemented Interfaces:

sirius.kernel.di.Initializable

public class Databases
extends Object
implements sirius.kernel.di.Initializable

Provides a DataSource which can be configured via the system configuration.

Use get(String) to obtain a managed connection to the given database.

Configuration is done via the system configuration. To declare a database provide an extension in jdbc.database. For examples see "component-db.conf".

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Databases.DatabaseMetricProvider Provides some metrics across all managed data sources.

Field Summary

Fields

Modifier and Type	Field and Description
protected static sirius.kernel.health.Log	LOG
protected static sirius.kernel.health.Counter	numConnects
protected static sirius.kernel.health.Counter	numQueries
protected static sirius.kernel.health.Counter	numSlowQueries
protected static sirius.kernel.health.Counter	numUses
protected static sirius.kernel.health.Average	queryDuration
protected static sirius.kernel.health.Log	SLOW_DB_LOG

Constructor Summary

Constructors

Constructor and Description
Databases()

Method Summary

Modifier and Type	Method and Description
static Object	convertValue(Object value) Transforms the given value into its database representation.
static LocalDateTime	decodeLocalDateTime(long timestamp) Decodes a long back into a LocalDateTime.
static long	encodeLocalDateTime(LocalDateTime date) Encodes a LocalDateTime as a long.
Row	fetchGeneratedKeys(PreparedStatement stmt) Returns all generated keys wrapped as row
Database	get(String name) Provides access to the selected database.
List<String>	getDatabases() Returns a list of all known (configured) databases from the system config.
protected static long	getLongConnectionThresholdMillis() Converts the threshold for "long connections" into a long containing milliseconds for performance reasons.
protected static long	getLongQueryThresholdMillis() Converts the threshold for "slow queries" into a long containing milliseconds for performance reasons.
boolean	hasDatabase(String name) Determines if a databse with the given name is present in the configuration.
void	initialize()
Set<String>	readColumns(ResultSet rs) Reads and returns all available columns of the given result set as upper case.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

protected static final sirius.kernel.health.Log LOG

SLOW_DB_LOG

protected static final sirius.kernel.health.Log SLOW_DB_LOG

numUses

protected static sirius.kernel.health.Counter numUses

numConnects

protected static sirius.kernel.health.Counter numConnects

numQueries

protected static sirius.kernel.health.Counter numQueries

numSlowQueries

protected static sirius.kernel.health.Counter numSlowQueries

queryDuration

protected static sirius.kernel.health.Average queryDuration

Constructor Detail

Databases

public Databases()

Method Detail

initialize

public void initialize()
                throws Exception

Specified by:

initialize in interface sirius.kernel.di.Initializable

Throws:

Exception

get

public Database get(String name)

Provides access to the selected database.

The configuration of the connection pool will be loaded from jdbc.database.[name]

Parameters:

name - name of the database to access

Returns:

a wrapper providing access to the given database

getDatabases

public List<String> getDatabases()

Returns a list of all known (configured) databases from the system config.

Returns:

a list of all known databases

hasDatabase

public boolean hasDatabase(String name)

Determines if a databse with the given name is present in the configuration.

Parameters:

name - the name of the database

Returns:

true if a configuration jdbc.database.[name] does exist, false otherwise

getLongQueryThresholdMillis

protected static long getLongQueryThresholdMillis()

Converts the threshold for "slow queries" into a long containing milliseconds for performance reasons.

Returns:

the threshold for long queries in milliseconds

getLongConnectionThresholdMillis

protected static long getLongConnectionThresholdMillis()

Converts the threshold for "long connections" into a long containing milliseconds for performance reasons.

Returns:

the threshold for long queries in milliseconds

encodeLocalDateTime

public static long encodeLocalDateTime(@Nullable
                                       LocalDateTime date)

Encodes a LocalDateTime as a long.

Basically the generated long consists of year_month_day_hour_minute_second to support sorting and ordering. Also we do not use timestamps as MySQL does autoupdate these unexpectedly and also because we do not need the millisecond resolution (it can even lead to errors).

Parameters:

date - the date to encode

Returns:

the date encoded as a sortable long or -1 if the given value was null

decodeLocalDateTime

@Nullable
public static LocalDateTime decodeLocalDateTime(long timestamp)

Decodes a long back into a LocalDateTime.

This is the inverse of encodeLocalDateTime(LocalDateTime).

Parameters:

timestamp - the number to decode

Returns:

the decoded date and time or null if the given number was negative

convertValue

public static Object convertValue(Object value)

Transforms the given value into its database representation.

Parameters:

value - the value to transform

Returns:

the database level representation of the given value

readColumns

public Set<String> readColumns(ResultSet rs)
                        throws SQLException

Reads and returns all available columns of the given result set as upper case.

Parameters:

rs - the result set to parse

Returns:

a set of columns within the given result set

Throws:

SQLException - in case of a database error

fetchGeneratedKeys

public Row fetchGeneratedKeys(PreparedStatement stmt)
                       throws SQLException

Returns all generated keys wrapped as row

Parameters:

stmt - the statement which was used to perform an update or insert

Returns:

a row containing all generated keys

Throws:

SQLException - in case of an error thrown by the database or driver