TilesView.java :  » J2EE » spring-ide_2.3.0 » org » springframework » web » servlet » view » tiles2 » Java Open Source

/*
 * Copyright 2002-2009 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.servlet.view.tiles2;

import java.util.Locale;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.tiles.TilesApplicationContext;
import org.apache.tiles.TilesContainer;
import org.apache.tiles.context.TilesRequestContext;
import org.apache.tiles.impl.BasicTilesContainer;
import org.apache.tiles.servlet.context.ServletTilesApplicationContext;
import org.apache.tiles.servlet.context.ServletTilesRequestContext;
import org.apache.tiles.servlet.context.ServletUtil;

import org.springframework.web.servlet.support.JstlUtils;
import org.springframework.web.servlet.support.RequestContext;
import org.springframework.web.servlet.view.AbstractUrlBasedView;
import org.springframework.web.util.WebUtils;

/**
 * {@link org.springframework.web.servlet.View} implementation that retrieves a
 * Tiles definition. The "url" property is interpreted as name of a Tiles definition.
 *
 * <p>This class builds on Tiles2, which requires JSP 2.0.
 * JSTL support is integrated out of the box due to JSTL's inclusion in JSP 2.0.
 * <b>Note: Spring 3.0 requires Tiles 2.1.2 or above.</b>
 *
 * <p>Depends on a TilesContainer which must be available in
 * the ServletContext. This container is typically set up via a
 * {@link TilesConfigurer} bean definition in the application context.
 *
 * @author Juergen Hoeller
 * @since 2.5
 * @see #setUrl
 * @see TilesConfigurer
 */
public class TilesView extends AbstractUrlBasedView {

  @Override
  public boolean checkResource(final Locale locale) throws Exception {
    TilesContainer container = ServletUtil.getContainer(getServletContext());
    if (!(container instanceof BasicTilesContainer)) {
      // Cannot check properly - let's assume it's there.
      return true;
    }
    BasicTilesContainer basicContainer = (BasicTilesContainer) container;
    TilesApplicationContext appContext = new ServletTilesApplicationContext(getServletContext());
    TilesRequestContext requestContext = new ServletTilesRequestContext(appContext, null, null) {
      @Override
      public Locale getRequestLocale() {
        return locale;
      }
    };
    return (basicContainer.getDefinitionsFactory().getDefinition(getUrl(), requestContext) != null);
  }

  @Override
  protected void renderMergedOutputModel(
      Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {

    ServletContext servletContext = getServletContext();
    TilesContainer container = ServletUtil.getContainer(servletContext);
    if (container == null) {
      throw new ServletException("Tiles container is not initialized. " +
          "Have you added a TilesConfigurer to your web application context?");
    }

    exposeModelAsRequestAttributes(model, request);
    JstlUtils.exposeLocalizationContext(new RequestContext(request, servletContext));

    if (!response.isCommitted()) {
      // Tiles is going to use a forward, but some web containers (e.g. OC4J 10.1.3)
      // do not properly expose the Servlet 2.4 forward request attributes... However,
      // must not do this on Servlet 2.5 or above, mainly for GlassFish compatibility.
      ServletContext sc = getServletContext();
      if (sc.getMajorVersion() == 2 && sc.getMinorVersion() < 5) {
        WebUtils.exposeForwardRequestAttributes(request);
      }
    }

    container.render(getUrl(), request, response);
  }

}