Use a wizard to fill in data piecewise. Spring web-flow (plugin) is recommended. An alternative is to use scope and ModelDriven interceptors together and have them use the same object. Here’s the idea coded:
public class SomeAction extends ActionSupport implements ModelDriven<somemodel> {
private SomeModel model;
public SomeAction ( ... ) {
model = new SomeModel( ... );
}
/** @see ModelDriven */
public SomeModel getModel() {
return model;
}
/** for scope interceptor */
public SomeModel getSessionModel() {
if ( ! clearSession )
return model;
clearSession = false;
return null;
}
public void setSessionModel( SomeModel newValue ) {
if ( newValue == null )
model.reset();
else
model.copyFrom( newValue );
}
}
NB! we’re stuck with the object returned by getModel(), so we should only change it’s content, not the object reference.
Action setup:
<action name="someAction" class="SomeAction">
<interceptor-ref name="scope">
<param name="session">sessionModel</param>
</interceptor-ref>
<interceptor-ref name="defaultStack" />
<result name="page1">/WEB-INF/jsp/page1.jsp</result>
<result name="page2">/WEB-INF/jsp/page2.jsp</result>
</action>
Scope-interceptor will call setSessionModel() with session data before other calls to Action (getModel, execute, validate), and after execute() returns getSessionModel() is called to get a new value to put in session.