The <javaModelGenerator> Element

The <javaModelGenerator> element is used to define properties of the Java model generator. The Java Model Generator builds primary key classes, record classes, and Query by Example classes that match the introspected table. This element is a required child element of the <context> element.

Required Attributes

Attribute Description
targetPackage This is the package where the generated classes will be placed. In the default generator, the property "enableSubPackages" controls how the actual package is calculated. If true, then the calculated package will be the targetPackage plus sub packages for the table's catalog and schema if they exist. If false (the default) then the calculated package will be exactly what is specified in the targetPackage attribute. MyBatis Generator will create folders as required for the generated packages.
targetProject This is used to specify a target project for the generated objects. When running in the Eclipse environment, this specifies the project and source folder where the objects will be saved. In other environments, this value should be an existing directory on the local file system. MyBatis Generator will not create this directory if it does not exist.

Optional Attributes

None

Child Elements

Supported Properties

This table lists the properties of the default Java model generators that can be specified with the <property> child element:

Property Name Property Values
constructorBased This property is used to select whether MyBatis Generator will generate a constructor for the class that accepts a value for each field in the class. Also, the SQL result map will be built to use the constructor rather than the "setter" for each field.

This property is only applicable for MyBatis3 and will be ignored for iBATIS2.

This property is ignored (and forced "true") if the "immutable" property is set "true".

This property can be overridden by the corresponding property in a <table> element.

The default value is false.

enableSubPackages This property is used to select whether MyBatis Generator will generate different Java packages for the objects based on the catalog and schema of the introspected table.

For example, suppose a table MYTABLE in schema MYSCHMA. Also suppose that the targetPackage attribute is set to "com.mycompany". If this property is true, the generated objects for the table will be placed in the package "com.mycompany.myschema". If the property is false, the generated objects will be placed in the "com.mycompany" schema.

The default value is false.

immutable This property is used to select whether MyBatis Generator will generate immutable model classes - this means that the classes will not have "setter" methods and the constructor will accept values for each field in the class.

If true, this forces the model classes to be built with paramterized constructors regardless of the value of the "constructorBased" property.

This property is only applicable for MyBatis3 and will be ignored for iBATIS2.

This property can be overridden by the corresponding property in a <table> element.

The default value is false.

rootClass This property can be used to specify a root class for all generated Java model objects. MyBatis Generator will specify this value as the super class of the primary key object, if the table has a primary key, or the record object otherwise. This value may be overridden by specifying the rootClass property on a Table configuration.

Important: If MyBatis Generator is able to load the root class, then it will not override a property in the root class that exactly matches a property that would normally be generated. An exact match of a property is defined as follows

  • Property name matches exactly
  • Property is of the same type
  • Property has a "getter" method
  • Property has a "setter" method

If specified, the value of this property should be a fully qualified class name (like com.mycompany.MyRootClass).

trimStrings This property is used to select whether MyBatis Generator adds code to trim the white space from character fields returned from the database. This can be useful if your database stores data in CHAR fields rather than VARCHAR fields. When true, MyBatis Generator will insert code to trim character fields. Can be overridden with the trimStrings property in a <table> or <columnOverride> element.

The default value is false.

Example

This element specifies that we always want to place generated classes in the "'test.model" package and that we want to use subpackages based on the table schema and catalog. We also want String columns trimmed.

<javaModelGenerator targetPackage="test.model"
     targetProject="\MyProject\src">
  <property name="enableSubPackages" value="true" />
  <property name="trimStrings" value="true" />
</javaModelGenerator>