Java Persistent Objects

SchemaTool

The meta-data files that accompany persistable classes define how a class maps across to a persistent store (e.g database). Database tables can be created by JPOX automatically by using the org.jpox.autoCreateSchema property. They can also be created manually by the user. In addition, JPOX provides a tool for creation/deletion/validation of these tables up front of actually running your JPOX enabled application -- called SchemaTool.

SchemaTool has 3 modes of operation.

create - all database tables required for a set of JDO MetaData files (and classes) will be created in the database schema.
delete - all database tables required for a set of JDO MetaData files (and classes) will be deleted from the database schema.
validate - all database tables required for a set of JDO MetaData files (and classes) will be validated for correct structure (just in case you have changed any of your class definitions, or MetaData files since last running JPOX).

Manual Usage

If you wish to call SchemaTool manually, it can be called as follows

java [-cp classpath] [system_props] org.jpox.SchemaTool [options] [jdo-files]
    where options can be
        -create : Create the tables specified by the jdo-files
        -delete : Delete the tables specified by the jdo-files
        -validate : Validate the tables specified by the jdo-files
    where system_props should include
        -Djavax.jdo.option.ConnectionDriverName=db_driver_name
        -Djavax.jdo.option.ConnectionURL=db_url
        -Djavax.jdo.option.ConnectionUserName=db_username
        -Djavax.jdo.option.ConnectionPassword=db_password
    and system_props could optionally include
        -Dlog4j.configuration=file:log4j_configuration_file.lcf

The classes and JDO MetaData files must be present in the CLASSPATH, and you should set the system properties above with your own values. You should only specify one of the [options] above.

Maven

If you are using Maven to build your system, you will need the JPOX Maven plugin. This provides 3 goals representing the different modes of SchemaTool. You can use the goals jpox:schema-create, jpox:schema-delete, jpox:schema-validate depending on whether you want to create, delete or validate the database tables. To use the JPOX Maven plugin you will need to set properties for the plugin (in your project.properties). For example

maven.jpox.database.driver=com.mysql.jdbc.Driver
maven.jpox.database.url=jdbc:mysql://localhost/jpox
maven.jpox.database.user=mysql
maven.jpox.database.password=
maven.jpox.log4j.configuration=file:log4j.lcf

So with these example properties I am setting the Maven plugin to use a MySQL database called "jpox", using a login of "mysql", etc. I am also specifying a log4j configuration file defining the logging for the SchemaTool process.

Ant

An Ant task is provided for using SchemaTool. It has classname org.jpox.SchemaToolTask, and accepts the following parameters

Parameter	Description	values
mode	Mode of operation.	create, delete, validate
verbose	Whether to give verbose output.	true, false

In addition to the parameters that the Ant task accepts, you will need to set up your CLASSPATH to include the classes and JDO MetaData files, and to define the following system properties via the sysproperty parameter

Parameter	Description	Optional
javax.jdo.option.ConnectionDriverName	Name of JDBC driver class	Mandatory
javax.jdo.option.ConnectionURL	URL for the database	Mandatory
javax.jdo.option.ConnectionUserName	User name for the database	Mandatory
javax.jdo.option.ConnectionPassword	Password for the database	Mandatory
log4j.configuration	Log4J configuration file, for SchemaTool's Log	Optional

So you could define something like the following, setting up the parameters schematool.classpath, javax.jdo.option.ConnectionDriverName, javax.jdo.option.ConnectionURL, javax.jdo.option.ConnectionUserName, and javax.jdo.option.ConnectionPassword to suit your situation.

You define the jdo files to create the tables using fileset.

<taskdef name="schematool" classname="org.jpox.SchemaToolTask" />

<schematool 
    failonerror="true"
    fork="true"
    verbose="true"
    mode="create">
    <classpath>
        <path refid="schematool.classpath"/>
    </classpath>
    <fileset dir="${classes.dir}">
        <include name="**/*.jdo"/>
    </fileset>            
    <sysproperty key="javax.jdo.option.ConnectionDriverName" value="${javax.jdo.option.ConnectionDriverName}"/>
    <sysproperty key="javax.jdo.option.ConnectionURL" value="${javax.jdo.option.ConnectionURL}"/>
    <sysproperty key="javax.jdo.option.ConnectionUserName" value="${javax.jdo.option.ConnectionUserName}"/>
    <sysproperty key="javax.jdo.option.ConnectionPassword" value="${javax.jdo.option.ConnectionPassword}"/>
</schematool>