/*
* Copyright 2002-2008 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.portlet.mvc;
import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;
import org.springframework.validation.BindException;
import org.springframework.web.portlet.ModelAndView;
import org.springframework.web.portlet.bind.PortletRequestDataBinder;
import org.springframework.web.portlet.util.PortletUtils;
/**
* <p>Abstract base class for custom command controllers. Autopopulates a
* command bean from the request. For command validation, a validator
* (property inherited from BaseCommandController) can be used.</p>
*
* <p>This command controller should preferrable not be used to handle form
* submission, because functionality for forms is more offered in more
* detail by the {@link org.springframework.web.portlet.mvc.AbstractFormController
* AbstractFormController} and its corresponding implementations.</p>
*
* <p><b><a name="config">Exposed configuration properties</a>
* (<a href="BaseCommandController.html#config">and those defined by superclass</a>):</b><br>
* <i>none</i> (so only those available in superclass).</p>
*
* <p><b><a name="workflow">Workflow
* (<a name="BaseCommandController.html#workflow">and that defined by superclass</a>):</b><br>
*
* @author John A. Lewis
* @author Juergen Hoeller
* @since 2.0
* @see #setCommandClass
* @see #setCommandName
* @see #setValidator
*/
public abstract class AbstractCommandController extends BaseCommandController {
/**
* This render parameter is used to indicate forward to the render phase
* that a valid command (and errors) object is in the session.
*/
private static final String COMMAND_IN_SESSION_PARAMETER = "command-in-session";
private static final String TRUE = Boolean.TRUE.toString();
/**
* Create a new AbstractCommandController.
*/
public AbstractCommandController() {
}
/**
* Create a new AbstractCommandController.
* @param commandClass class of the command bean
*/
public AbstractCommandController(Class commandClass) {
setCommandClass(commandClass);
}
/**
* Create a new AbstractCommandController.
* @param commandClass class of the command bean
* @param commandName name of the command bean
*/
public AbstractCommandController(Class commandClass, String commandName) {
setCommandClass(commandClass);
setCommandName(commandName);
}
protected final void handleActionRequestInternal(ActionRequest request, ActionResponse response)
throws Exception {
// Create the command object.
Object command = getCommand(request);
// Compute the errors object.
PortletRequestDataBinder binder = bindAndValidate(request, command);
BindException errors = new BindException(binder.getBindingResult());
// Actually handle the action.
handleAction(request, response, command, errors);
// Pass the command and errors forward to the render phase.
setRenderCommandAndErrors(request, command, errors);
setCommandInSession(response);
}
protected final ModelAndView handleRenderRequestInternal(
RenderRequest request, RenderResponse response) throws Exception {
Object command = null;
BindException errors = null;
// Get the command and errors objects from the session, if they exist.
if (isCommandInSession(request)) {
logger.debug("Render phase obtaining command and errors objects from session");
command = getRenderCommand(request);
errors = getRenderErrors(request);
}
else {
logger.debug("Render phase creating new command and errors objects");
command = getCommand(request);
PortletRequestDataBinder binder = bindAndValidate(request, command);
errors = new BindException(binder.getBindingResult());
}
return handleRender(request, response, command, errors);
}
/**
* Template method for request handling, providing a populated and validated instance
* of the command class, and an Errors object containing binding and validation errors.
* <p>Call <code>errors.getModel()</code> to populate the ModelAndView model
* with the command and the Errors instance, under the specified command name,
* as expected by the "spring:bind" tag.
* @param request current action request
* @param response current action response
* @param command the populated command object
* @param errors validation errors holder
* @see org.springframework.validation.Errors
* @see org.springframework.validation.BindException#getModel
*/
protected abstract void handleAction(
ActionRequest request, ActionResponse response, Object command, BindException errors)
throws Exception;
/**
* Template method for render request handling, providing a populated and validated instance
* of the command class, and an Errors object containing binding and validation errors.
* <p>Call <code>errors.getModel()</code> to populate the ModelAndView model
* with the command and the Errors instance, under the specified command name,
* as expected by the "spring:bind" tag.
* @param request current render request
* @param response current render response
* @param command the populated command object
* @param errors validation errors holder
* @return a ModelAndView to render, or null if handled directly
* @see org.springframework.validation.Errors
* @see org.springframework.validation.BindException#getModel
*/
protected abstract ModelAndView handleRender(
RenderRequest request, RenderResponse response, Object command, BindException errors)
throws Exception;
/**
* Return the name of the render parameter that indicates there
* is a valid command (and errors) object in the session.
* @return the name of the render parameter
* @see javax.portlet.RenderRequest#getParameter
*/
protected String getCommandInSessionParameterName() {
return COMMAND_IN_SESSION_PARAMETER;
}
/**
* Set the action response parameter that indicates there is a
* command (and errors) object in the session for the render phase.
* @param response the current action response
* @see #getCommandInSessionParameterName
* @see #isCommandInSession
*/
protected final void setCommandInSession(ActionResponse response) {
if (logger.isDebugEnabled()) {
logger.debug("Setting render parameter [" + getCommandInSessionParameterName() +
"] to indicate a valid command (and errors) object are in the session");
}
try {
response.setRenderParameter(getCommandInSessionParameterName(), TRUE);
}
catch (IllegalStateException ex) {
// Ignore in case sendRedirect was already set.
}
}
/**
* Determine if there is a valid command (and errors) object in the
* session for this render request.
* @param request current render request
* @return if there is a valid command object in the session
* @see #getCommandInSessionParameterName
* @see #setCommandInSession
*/
protected boolean isCommandInSession(RenderRequest request) {
return (TRUE.equals(request.getParameter(getCommandInSessionParameterName())) &&
PortletUtils.getSessionAttribute(request, getRenderCommandSessionAttributeName()) != null);
}
}