JDBC Package, Driver Class, and Environment Class

JDBC Package

Obtain the driver package named GaussDB-Kernel-VxxxRxxxCxx-OS version number-64bit-Jdbc.tar.gz.

After the decompression, you will obtain the following JDBC packages in .jar format:

• gsjdbc4.jar: The driver class name and loading path are the same as those of PostgreSQL driver, which facilitates the migration of services running on PostgreSQL. However, some interfaces supported by gsjdbc4.jar are different from those supported by PostgreSQL and need to be adjusted on the service side.
• gsjdbc200.jar: The driver class name and loading path are the same as those of GaussDB 200, which facilitates the migration of services running on GaussDB 200. However, some interfaces supported by gsjdbc200.jar are different from those supported by GaussDB 200 and need to be adjusted on the service side.
• opengaussjdbc.jar: The main class name is com.huawei.opengauss.jdbc.Driver. The URL prefix of the database connection is jdbc:opengauss. This driver package is recommended. This driver package is used when both PostgreSQL and GaussDB are accessed in a JVM process.
  

  • The loading paths of driver classes in different driver packages are different, but the interface functions are the same.
  • The gsjdbc4 driver package cannot be used to operate the PostgreSQL database. Although the connection can be successfully established in some versions, some interface behaviors are different from those of PostgreSQL JDBC, which may cause unknown errors.
  • The PostgreSQL driver package cannot be used to operate the GaussDB database. Although the connection can be successfully established in some versions, some interface behaviors are different from those of GaussDB JDBC, which may cause unknown errors.

Driver Class

Before creating a database connection, load the database driver class org.postgresql.Driver (decompressed from gsjdbc4.jar).

1. GaussDB is compatible with PostgreSQL in the use of JDBC. Therefore, when two JDBC drivers are used in the same process, class names may conflict.
2. JDBC of this version does not support identity & access management suite (IAM) for authentication.
3. Compared with the PostgreSQL driver, the GaussDB JDBC driver has the following enhanced features:
   1. The SHA256 encryption mode is supported for login.
   2. The third-party log framework that implements the sf4j API can be connected.
   3. Distributed load balancing at the connection level is supported.
   4. DR failover is supported.

Environment Class

JDK 1.8 must be configured on the client. JDK supports multiple platforms such as Windows and Linux. The following uses Windows as an example to describe how to configure JDK.

1. Open the command prompt in Windows, and run java -version to check the JDK version. Ensure that the JDK version is 1.8. If the JDK is not installed, download the installation package and install it.
2. On the Windows desktop, right-click This PC and choose Properties from the shortcut menu.
3. In the displayed System window, click Advanced system settings in the navigation tree on the left.
4. In the System Properties dialog box, click Environment Variables in the lower right corner.
5. In the System variables area of the Environment Variables dialog box that is displayed, set the following variables.

   Variable	Operation	Variable Value
   JAVA_HOME	If the variable exists, click Edit. If the variable does not exist, click New.	Specifies the Java installation directory. Example: C:\Program Files\Java\jdk1.8.0_131
   Path	Edit	If JAVA_HOME is configured, add %JAVA_HOME%\bin before the variable value. If JAVA_HOME is not configured, add the full Java installation path before the variable value: C:\Program Files\Java\jdk1.8.0_131\bin;
   CLASSPATH	New	.;%JAVA_HOME%\lib;%JAVA_HOME%\lib\tools.jar;

6. Click OK and close the windows one by one.