001// Copyright 2008, 2009 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.internal.spring;
016
017import org.apache.tapestry5.ioc.internal.util.InternalUtils;
018import org.apache.tapestry5.spring.ApplicationContextCustomizer;
019import org.apache.tapestry5.spring.TapestryApplicationContext;
020import org.springframework.context.ApplicationContextException;
021import org.springframework.web.context.ConfigurableWebApplicationContext;
022import org.springframework.web.context.ContextLoader;
023
024import javax.servlet.ServletContext;
025
026public class CustomizingContextLoader extends ContextLoader
027{
028    private final ApplicationContextCustomizer customizer;
029
030    public CustomizingContextLoader(ApplicationContextCustomizer customizer)
031    {
032        this.customizer = customizer;
033    }
034
035    @Override
036    protected void customizeContext(ServletContext servletContext, ConfigurableWebApplicationContext applicationContext)
037    {
038        customizer.customizeApplicationContext(servletContext, applicationContext);
039    }
040
041    @Override
042    protected Class determineContextClass(ServletContext servletContext) throws ApplicationContextException
043    {
044        String contextClassName = servletContext.getInitParameter(CONTEXT_CLASS_PARAM);
045
046        if (InternalUtils.isNonBlank(contextClassName))
047        {
048            Class result = super.determineContextClass(servletContext);
049
050            if (!TapestryApplicationContext.class.isAssignableFrom(result))
051                throw new IllegalArgumentException(String.format(
052                        "When using the Tapestry/Spring integration library, you must specifiy a context class that extends from %s. Class %s does not. Update the '%s' servlet context init parameter.",
053                        TapestryApplicationContext.class.getName(),
054                        result.getName(),
055                        CONTEXT_CLASS_PARAM));
056
057            return result;
058        }
059
060        return TapestryApplicationContext.class;
061    }
062}