```
@Target(TYPE)
@Retention(RUNTIME)
@Repeatable(DataSourceDefinitions.class)
public @interface DataSourceDefinition
```
Annotation used to define a container DataSource to be registered with JNDI. The DataSource may be configured by setting the annotation elements for commonly used DataSource properties. Additional standard and vendor-specific properties may be specified using the properties element.
The data source will be registered under the name specified in the name element. It may be defined to be in any valid Jakarta EE namespace, which will determine the accessibility of the data source from other components.
A JDBC driver implementation class of the appropriate type, either DataSource, ConnectionPoolDataSource, or XADataSource, must be indicated by the className element. The availability of the driver class will be assumed at runtime.
DataSource properties should not be specified more than once. If the url annotation element contains a DataSource property that was also specified using the corresponding annotation element or was specified in the properties annotation element, the precedence order is undefined and implementation specific:
```
   @DataSourceDefinition(name="java:global/MyApp/MyDataSource",
      className="org.apache.derby.jdbc.ClientDataSource",
      url="jdbc:derby://localhost:1527/myDB;user=bill",
      user="lance",
      password="secret",
      databaseName="testDB",
      serverName="luckydog"
   )// DO NOT DO THIS!!!
 
```
In the above example, the databaseName, user and serverName properties were specified as part of the url property and using the corresponding annotation elements. This should be avoided.
If the properties annotation element is used and contains a DataSource property that was also specified using the corresponding annotation element, the annotation element value takes precedence. For example:
```
   @DataSourceDefinition(name="java:global/MyApp/MyDataSource",
      className="org.apache.derby.jdbc.ClientDataSource",
      user="lance",
      password="secret",
      databaseName="testDB",
      serverName="luckydog",
       properties= {"databaseName=myDB", "databaseProp=doThis"}
   )// DO NOT DO THIS!!!
 
```
This would result in the following values being used when configuring the DataSource:
- serverName=luckydog
- portNumber=1527
- databaseName=testDB
- user=lance
- password=secret
- databaseProp=doThis
Vendors are not required to support properties that do not normally apply to a specific data source type. For example, specifying the transactional property to be true but supplying a value for className that implements a data source class other than XADataSource may not be supported.
Vendor-specific properties may be combined with or used to override standard data source properties defined using this annotation.
DataSource properties that are specified and are not supported in a given configuration or cannot be mapped to a vendor specific configuration property may be ignored.
Examples:
```
   @DataSourceDefinition(name="java:global/MyApp/MyDataSource",
      className="com.foobar.MyDataSource",
      portNumber=6689,
      serverName="myserver.com",
      user="lance",
      password="secret"
   )

 
```
Using a URL:
```
  @DataSourceDefinition(name="java:global/MyApp/MyDataSource",
    className="org.apache.derby.jdbc.ClientDataSource",
    url="jdbc:derby://localhost:1527/myDB",
    user="lance",
    password="secret"
 )
 
```
An example lookup of the DataSource from an Jakarta Enterprise Beans:
```
 @Stateless
 public class MyStatelessEJB {
   @Resource(lookup="java:global/MyApp/myDataSource")
    DataSource myDB;
      ...
 }
 
```
See Also:

DataSource, XADataSource, ConnectionPoolDataSource

Required Element Summary

Required Elements
Modifier and Type	Required Element	Description
`String`	`className`	Name of a DataSource class that implements `javax.sql.DataSource` or `javax.sql.XADataSource` or `javax.sql.ConnectionPoolDataSource`.
`String`	`name`	JNDI name by which the data source will be registered.

Optional Element Summary

Optional Elements
Modifier and Type	Optional Element	Description
`String`	`databaseName`	Name of a database on a server.
`String`	`description`	Description of this data source
`int`	`initialPoolSize`	Number of connections that should be created when a connection pool is initialized.
`int`	`isolationLevel`	Isolation level for connections.
`int`	`loginTimeout`	Sets the maximum time in seconds that this data source will wait while attempting to connect to a database.
`int`	`maxIdleTime`	The number of seconds that a physical connection should remain unused in the pool before the connection is closed for a connection pool.
`int`	`maxPoolSize`	Maximum number of connections that should be concurrently allocated for a connection pool.
`int`	`maxStatements`	The total number of statements that a connection pool should keep open.
`int`	`minPoolSize`	Minimum number of connections that should be allocated for a connection pool.
`String`	`password`	Password to use for connection authentication.
`int`	`portNumber`	Port number where a server is listening for requests.
`String[]`	`properties`	Used to specify vendor-specific properties and less commonly used `DataSource` properties such as:
`String`	`serverName`	Database server name.
`boolean`	`transactional`	Set to `false` if connections should not participate in transactions.
`String`	`url`	A JDBC URL.
`String`	`user`	User name to use for connection authentication.

- Element Detail
  - name
```
String name
```
    JNDI name by which the data source will be registered.
- - className
```
String className
```
    Name of a DataSource class that implements javax.sql.DataSource or javax.sql.XADataSource or javax.sql.ConnectionPoolDataSource.
- - description
```
String description
```
    Description of this data source
    
    Default:
    
    ""
- - url
```
String url
```
    A JDBC URL. If the url annotation element contains a DataSource property that was also specified using the corresponding annotation element, the precedence order is undefined and implementation specific.
    
    Default:
    
    ""
- - user
```
String user
```
    User name to use for connection authentication.
    
    Default:
    
    ""
- - password
```
String password
```
    Password to use for connection authentication.
    
    Default:
    
    ""
- - databaseName
```
String databaseName
```
    Name of a database on a server.
    
    Default:
    
    ""
- - portNumber
```
int portNumber
```
    Port number where a server is listening for requests.
    
    Default:
    
    -1
- - serverName
```
String serverName
```
    Database server name.
    
    Default:
    
    "localhost"
- - isolationLevel
```
int isolationLevel
```
    Isolation level for connections. The Isolation level must be one of the following:
    
    Connection.TRANSACTION_NONE,
    Connection.TRANSACTION_READ_ UNCOMMITTED,
    Connection.TRANSACTION_READ_COMMITTED,
    Connection.TRANSACTION_REPEATABLE_READ,
    Connection.TRANSACTION_SERIALIZABLE
    
    Default is vendor-specific.
    Default:
    
    -1
- - transactional
```
boolean transactional
```
    Set to false if connections should not participate in transactions.
    Default is to enlist in a transaction when one is active or becomes active.
    
    Default:
    
    true
- - initialPoolSize
```
int initialPoolSize
```
    Number of connections that should be created when a connection pool is initialized.
    Default is vendor-specific
    
    Default:
    
    -1
- - maxPoolSize
```
int maxPoolSize
```
    Maximum number of connections that should be concurrently allocated for a connection pool.
    Default is vendor-specific.
    
    Default:
    
    -1
- - minPoolSize
```
int minPoolSize
```
    Minimum number of connections that should be allocated for a connection pool.
    Default is vendor-specific.
    
    Default:
    
    -1
- - maxIdleTime
```
int maxIdleTime
```
    The number of seconds that a physical connection should remain unused in the pool before the connection is closed for a connection pool.
    Default is vendor-specific
    
    Default:
    
    -1
- - maxStatements
```
int maxStatements
```
    The total number of statements that a connection pool should keep open. A value of 0 indicates that the caching of statements is disabled for a connection pool.
    Default is vendor-specific
    
    Default:
    
    -1
- - properties
```
String[] properties
```
    Used to specify vendor-specific properties and less commonly used DataSource properties such as:
    
    dataSourceName
    networkProtocol
    propertyCycle
    roleName
    
    Properties are specified using the format: propertyName=propertyValue with one property per array element.
    If a DataSource property is specified in the properties element and the annotation element for the property is also specified, the annotation element value takes precedence.
    Default:
    
    {}
- - loginTimeout
```
int loginTimeout
```
    Sets the maximum time in seconds that this data source will wait while attempting to connect to a database. A value of zero specifies that the timeout is the default system timeout if there is one; otherwise, it specifies that there is no timeout.
    Default is vendor-specific.
    
    Default:
    
    0

Annotation Type DataSourceDefinition

Required Element Summary

Optional Element Summary

Element Detail

name

className

description

url

user

password

databaseName

portNumber

serverName

isolationLevel

transactional

initialPoolSize

maxPoolSize

minPoolSize

maxIdleTime

maxStatements

properties

loginTimeout