Register the JDBC drivers
To access a database from a Java application, you must first provide the code to register your installed driver with your program. You do this with the static registerDriver() method of the java.sql.DriverManager class. This class provides a basic service for managing a set of JDBC drivers. The registerDriver() method takes as input a «driver» class, that is, a class that implements the java.sql.Driver interface, as is the case with OracleDriver . Note: Alternatively, you can use the forName() method of the java.lang.Class class to load the JDBC drivers directly. For example: Class.forName («oracle.jdbc.OracleDriver»); . However, this method is valid only for JDK-compliant Java virtual machines. It is not valid for Microsoft Java virtual machines. You register the driver only once in your Java application.
DriverManager.registerDriver (new oracle.jdbc.OracleDriver()); Open a Connection to a database
Once you have registered the driver, you can open a connection to the database with the static getConnection() method of the java.sql.DriverManager class. The type of the object returned is java.sql.Connection .
Understanding the Forms of getConnection()
Specifying a Databse URL, User Name, and Password
The following signature takes the URL, user name, and password as separate parameters: getConnection(String URL, String user, String password); Where the URL is of the form:
jdbc:oracle::@ The following example connects user scott with password tiger to a database with SID orcl through port 1521 of host myhost , using the Thin driver. Connection conn = DriverManager.getConnection
(«jdbc:oracle:thin:@myhost:1521:orcl», «scott», «tiger»);
Specifying a Databse URL That Includes User Name and Password
The following signature takes the URL, user name, and password all as part of a URL parameter: getConnection(String URL); Where the URL is of the form:
jdbc:oracle::/@ The following example connects user scott with password tiger to a database on host myhost using the OCI driver. In this case, however, the URL includes the userid and password, and is the only input parameter. Connection conn = DriverManager.getConnection
(«jdbc:oracle:oci8:scott/tiger@myhost); If you want to connect with the Thin driver, you must specify the port number and SID. For example, if you want to connect to the database on host myhost that has a TCP/IP listener up on port 1521, and the SID (system identifier) is orcl : Connection conn = DriverManager.getConnection
(«jdbc:oracle:thin:scott/tiger@myhost:1521:orcl);
Specifying a Database URL and Properties Object
The following signature takes a URL, together with a properties object that specifies user name and password (perhaps among other things): getConnection(String URL, Properties info); Where the URL is of the form:
jdbc:oracle::@ In addition to the URL, use an object of the standard Java Properties class as input. For example: java.util.Properties info = new java.util.Properties();
info.put («user», «scott»);
info.put ( «password», «tiger» );
info.put («defaultRowPrefetch»,»15″);
getConnection («jdbc:oracle:oci8:@»,info); The table below lists the connection properties that Oracle JDBC drivers support. Connection Properties Recognized by Oracle JDBC Drivers
| Name | Short Name | Type | Description |
|---|---|---|---|
| user | n/a | String | the user name for logging into the database |
| password | n/a | String | the password for logging into the database |
| database | server | String | the connect string for the database |
| internal_logon | n/a | String | a role, such as sysdba or sysoper , that allows you to log on as sys |
| defaultRowPrefetch | prefetch | String (containing integer value) | the default number of rows to prefetch from the server (default value is «10») |
| remarksReporting | remarks | String (containing boolean value) | «true» if getTables() and getColumns() should report TABLE_REMARKS; equivalent to using setRemarksReporting() (default value is «false») |
| defaultBatchValue | batchvalue | String (containing integer value) | the default batch value that triggers an execution request (default value is «10») |
| includeSynonyms | synonyms | String (containing boolean value) | «true» to include column information from predefined «synonym» SQL entities when you execute a DataBaseMetaData getColumns() call; equivalent to connection setIncludeSynonyms() call (default value is «false») |
| processEscapes | n/a | String (containing boolean value) | «false» to disable escape processing for statements (Statement or PreparedStatement) created from this connection. Set this to «false» if you want to avoid many calls to Statement.setEscapeProcessing(false); . This is espcially usefull for PreparedStatement where a call to setEscapeProcessing(false) would have no effect. The default is «true». |
| defaultNChar | n/a | String (containing boolean value) | «false» is the default. If set to «true», the default behavior for handling character datatypes is changed so that NCHAR/NVARCHAR2 become the default. This means that setFormOfUse() won’t be needed anymore when using NCHAR/NVARCHAR2. This can also be set as a java property : java -Doracle.jdbc.defaultNChar=true myApplication |
| useFetchSizeWithLongColumn | n/a | String (containing boolean value) | «false» is the default. THIS IS A THIN ONLY PROPERTY. IT SHOULD NOT BE USED WITH ANY OTHER DRIVERS. If set to «true», the performance when retrieving data in a ‘SELECT’ will be improved but the default behavior for handling LONG columns will be changed to fetch multiple rows (prefetch size). It means that enough memory will be allocated to read this data. So if you want to use this property, make sure that the LONG columns you are retrieving are not too big or you may run out of memory. This property can also be set as a java property : java -Doracle.jdbc.useFetchSizeWithLongColumn=true myApplication |
| SetFloatAndDoubleUseBinary | n/a | String (containing boolean value) | «false» is the default. If set to «true», causes the java.sql.PreparedStatment setFloat and setDouble API’s to use internal binary format as for BINARY_FLOAT and BINARY_DOUBLE parameters. See oracle.jdbc.OraclePreparedStatement setBinaryFloat and setBinaryDouble |
Select your driver type : thin, oci, kprb.
- Thin Driver, a 100% Java driver for client-side use without an Oracle installation, particularly with applets. The Thin driver type is thin . To connect user scott with password tiger to a database with SID (system identifier) orcl through port 1521 of host myhost , using the Thin driver, you would write :
Connection conn = DriverManager.getConnection ("jdbc:oracle:thin:@myhost:1521:orcl", "scott", "tiger"); Connection conn = DriverManager.getConnection ("jdbc:oracle:oci:@myhost:1521:orcl", "scott", "tiger"); Note that you can also specify the database by a TNSNAMES entry. You can find the available TNSNAMES entries listed in the file tnsnames.ora on the client computer from which you are connecting. For example, if you want to connect to the database on host myhost as user scott with password tiger that has a TNSNAMES entry of MyHostString , enter:
Connection conn = DriverManager.getConnection ("jdbc:oracle:oci8:@MyHostString","scott","tiger"); If your JDBC client and Oracle server are running on the same machine, the OCI driver can use IPC (InterProcess Communication) to connect to the database instead of a network connection. An IPC connection is much faster than a network connection.
Connection conn = DriverManager.getConnection ("jdbc:oracle:oci8:@","scott","tiger"); DriverManager.getConnection("jdbc:oracle:kprb:");or:DriverManager.getConnection("jdbc:default:connection:");
You can also use the Oracle-specific defaultConnection() method of the OracleDriver class which is generally recommended:
OracleDriver ora = new OracleDriver(); Connection conn = ora.defaultConnection();