VoltDB client applications written in Java compile and run like other Java applications. (See Chapter 8, Using VoltDB with Other Programming Languages for more on writing client applications using other languages.) To compile, you must include the VoltDB libraries in the classpath so Java can resolve references to the VoltDB classes and methods. It is possible to do this manually by defining the environment variable CLASSPATH or by using the -classpath argument on the command line. If your client application depends on other libraries, they need to be included in the classpath as well. You can also specify where to create the resulting class files using the -d flag to specify an output directory, as in the following example:

$ javac -classpath "./:/opt/voltdb/voltdb/*" \
        -d ./obj  \
         *.java

The preceding example assumes that the VoltDB software has been installed in the folder /opt/voltdb. If you installed VoltDB in a different directory, you need to include your installation path in the -classpath argument.

If you are using Apache Maven to manage your application development, the VoltDB Java client library is available from the central Maven repository. So rather than installing VoltDB locally, you can simply include it as a dependency in your Maven project object model, or pom.xml, like so:

<dependency>
    <groupId>org.voltdb</groupId>
    <artifactId>voltdbclient</artifactId>
    <version>5.1</version>
</dependency>

$ java -classpath "./:/opt/voltdb/voltdb/*"  MyClientApp