4.1.1 Properties

A DataSource object has a set of properties that identify and describe the real world data source that it represents. These properties include information like the location of the database server, the name of the database, the network protocol to use to communicate with the server, and so on. DataSource properties follow the JavaBeans design pattern and are usually set when a DataSource object is deployed.
To encourage uniformity among DataSource implementations from different vendors, the JDBC 2.0 API specifies a standard set of properties and a standard name for each property. The following table gives the standard name, the data type, and a description for each of the standard properties. Note that a DataSource implementation does not have to support all of these properties; the table just shows the standard name that an implementation should use when it supports a property.
Table 4.1 Standard Data Source Properties

Property Name Type Description
DatabaseName String the name of a particular database on a server
DataSourceName String the logical name for the underlying XADataSource or ConnectionPoolDataSource object; used only when pooling of connections or distributed transactions are implemented
Description String a description of this data source
NetworkProtocol String the network protocol used to communicate with the server
Password String the user's database password
PortNumber int the port number where a server is listening for requests
RoleName String the initial SQL rolename
ServerName String the database server name
user String the user's account name
A DataSource object will, of course, have to support all of the properties that the data source it represents needs for making a connection, but the only property that all DataSource implementations are required to support is the description property. This standardizing of properties makes it possible, for instance, for a utility to be written that lists available data sources, giving a description of each along with the other property information that is available.
A DataSource object is not restricted to using only those properties specified in Table 4.1. A vendor may add its own properties, in which case it should give each new property a vendor-specific name.
If a DataSource object supports a property, it must supply getter and setter methods for it. The following code fragment illustrates the methods that a DataSource object ds would need to include if it supports, for example, the property serverName.

ds.setServerName("my_database_server");
String serverName = ds.getServerName();

Properties will most likely be set by a developer or system administrator using a GUI tool as part of the installation of the data source. Users connecting to the data source do not get or set properties. This is enforced by the fact that the DataSource interface does not include the getter and setter methods for properties; they are supplied only in a particular implementation. The effect of including getter and setter methods in the implementation but not the public interface creates some separation between the management API for DataSource objects and the API used by applications. Management tools can get at properties by using introspection.