001/* 002 * Copyright 2002-2019 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.beans.factory.xml; 018 019import java.io.IOException; 020 021import org.xml.sax.EntityResolver; 022import org.xml.sax.InputSource; 023import org.xml.sax.SAXException; 024 025import org.springframework.util.Assert; 026 027/** 028 * {@link EntityResolver} implementation that delegates to a {@link BeansDtdResolver} 029 * and a {@link PluggableSchemaResolver} for DTDs and XML schemas, respectively. 030 * 031 * @author Rob Harrop 032 * @author Juergen Hoeller 033 * @author Rick Evans 034 * @since 2.0 035 * @see BeansDtdResolver 036 * @see PluggableSchemaResolver 037 */ 038public class DelegatingEntityResolver implements EntityResolver { 039 040 /** Suffix for DTD files */ 041 public static final String DTD_SUFFIX = ".dtd"; 042 043 /** Suffix for schema definition files */ 044 public static final String XSD_SUFFIX = ".xsd"; 045 046 047 private final EntityResolver dtdResolver; 048 049 private final EntityResolver schemaResolver; 050 051 052 /** 053 * Create a new DelegatingEntityResolver that delegates to 054 * a default {@link BeansDtdResolver} and a default {@link PluggableSchemaResolver}. 055 * <p>Configures the {@link PluggableSchemaResolver} with the supplied 056 * {@link ClassLoader}. 057 * @param classLoader the ClassLoader to use for loading 058 * (can be {@code null}) to use the default ClassLoader) 059 */ 060 public DelegatingEntityResolver(ClassLoader classLoader) { 061 this.dtdResolver = new BeansDtdResolver(); 062 this.schemaResolver = new PluggableSchemaResolver(classLoader); 063 } 064 065 /** 066 * Create a new DelegatingEntityResolver that delegates to 067 * the given {@link EntityResolver EntityResolvers}. 068 * @param dtdResolver the EntityResolver to resolve DTDs with 069 * @param schemaResolver the EntityResolver to resolve XML schemas with 070 */ 071 public DelegatingEntityResolver(EntityResolver dtdResolver, EntityResolver schemaResolver) { 072 Assert.notNull(dtdResolver, "'dtdResolver' is required"); 073 Assert.notNull(schemaResolver, "'schemaResolver' is required"); 074 this.dtdResolver = dtdResolver; 075 this.schemaResolver = schemaResolver; 076 } 077 078 079 @Override 080 public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException { 081 if (systemId != null) { 082 if (systemId.endsWith(DTD_SUFFIX)) { 083 return this.dtdResolver.resolveEntity(publicId, systemId); 084 } 085 else if (systemId.endsWith(XSD_SUFFIX)) { 086 return this.schemaResolver.resolveEntity(publicId, systemId); 087 } 088 } 089 090 // Fall back to the parser's default behavior. 091 return null; 092 } 093 094 095 @Override 096 public String toString() { 097 return "EntityResolver delegating " + XSD_SUFFIX + " to " + this.schemaResolver + 098 " and " + DTD_SUFFIX + " to " + this.dtdResolver; 099 } 100 101}