001/* 002 * Copyright 2002-2014 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.ui.freemarker; 018 019import java.io.IOException; 020import java.io.InputStreamReader; 021import java.io.Reader; 022 023import freemarker.cache.TemplateLoader; 024import org.apache.commons.logging.Log; 025import org.apache.commons.logging.LogFactory; 026 027import org.springframework.core.io.Resource; 028import org.springframework.core.io.ResourceLoader; 029 030/** 031 * FreeMarker {@link TemplateLoader} adapter that loads via a Spring {@link ResourceLoader}. 032 * Used by {@link FreeMarkerConfigurationFactory} for any resource loader path that cannot 033 * be resolved to a {@link java.io.File}. 034 * 035 * @author Juergen Hoeller 036 * @since 14.03.2004 037 * @see FreeMarkerConfigurationFactory#setTemplateLoaderPath 038 * @see freemarker.template.Configuration#setDirectoryForTemplateLoading 039 */ 040public class SpringTemplateLoader implements TemplateLoader { 041 042 protected final Log logger = LogFactory.getLog(getClass()); 043 044 private final ResourceLoader resourceLoader; 045 046 private final String templateLoaderPath; 047 048 049 /** 050 * Create a new SpringTemplateLoader. 051 * @param resourceLoader the Spring ResourceLoader to use 052 * @param templateLoaderPath the template loader path to use 053 */ 054 public SpringTemplateLoader(ResourceLoader resourceLoader, String templateLoaderPath) { 055 this.resourceLoader = resourceLoader; 056 if (!templateLoaderPath.endsWith("/")) { 057 templateLoaderPath += "/"; 058 } 059 this.templateLoaderPath = templateLoaderPath; 060 if (logger.isInfoEnabled()) { 061 logger.info("SpringTemplateLoader for FreeMarker: using resource loader [" + this.resourceLoader + 062 "] and template loader path [" + this.templateLoaderPath + "]"); 063 } 064 } 065 066 067 @Override 068 public Object findTemplateSource(String name) throws IOException { 069 if (logger.isDebugEnabled()) { 070 logger.debug("Looking for FreeMarker template with name [" + name + "]"); 071 } 072 Resource resource = this.resourceLoader.getResource(this.templateLoaderPath + name); 073 return (resource.exists() ? resource : null); 074 } 075 076 @Override 077 public Reader getReader(Object templateSource, String encoding) throws IOException { 078 Resource resource = (Resource) templateSource; 079 try { 080 return new InputStreamReader(resource.getInputStream(), encoding); 081 } 082 catch (IOException ex) { 083 if (logger.isDebugEnabled()) { 084 logger.debug("Could not find FreeMarker template: " + resource); 085 } 086 throw ex; 087 } 088 } 089 090 @Override 091 public long getLastModified(Object templateSource) { 092 Resource resource = (Resource) templateSource; 093 try { 094 return resource.lastModified(); 095 } 096 catch (IOException ex) { 097 if (logger.isDebugEnabled()) { 098 logger.debug("Could not obtain last-modified timestamp for FreeMarker template in " + 099 resource + ": " + ex); 100 } 101 return -1; 102 } 103 } 104 105 @Override 106 public void closeTemplateSource(Object templateSource) throws IOException { 107 } 108 109}