001/*
002 * Copyright 2002-2012 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.servlet.handler;
018
019import java.io.IOException;
020import javax.servlet.ServletException;
021import javax.servlet.http.HttpServletRequest;
022import javax.servlet.http.HttpServletResponse;
023
024import org.springframework.core.convert.ConversionService;
025import org.springframework.util.Assert;
026
027/**
028 * Interceptor that places the configured {@link ConversionService} in request scope
029 * so it's available during request processing. The request attribute name is
030 * "org.springframework.core.convert.ConversionService", the value of
031 * {@code ConversionService.class.getName()}.
032 *
033 * <p>Mainly for use within JSP tags such as the spring:eval tag.
034 *
035 * @author Keith Donald
036 * @since 3.0.1
037 */
038public class ConversionServiceExposingInterceptor extends HandlerInterceptorAdapter {
039
040        private final ConversionService conversionService;
041
042
043        /**
044         * Creates a new {@link ConversionServiceExposingInterceptor}.
045         * @param conversionService the conversion service to export to request scope when this interceptor is invoked
046         */
047        public ConversionServiceExposingInterceptor(ConversionService conversionService) {
048                Assert.notNull(conversionService, "The ConversionService may not be null");
049                this.conversionService = conversionService;
050        }
051
052
053        @Override
054        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
055                        throws ServletException, IOException {
056
057                request.setAttribute(ConversionService.class.getName(), this.conversionService);
058                return true;
059        }
060
061}