001/* 002 * Copyright 2002-2018 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.http.converter.xml; 018 019import javax.xml.transform.Result; 020import javax.xml.transform.Source; 021 022import org.springframework.beans.TypeMismatchException; 023import org.springframework.http.HttpHeaders; 024import org.springframework.http.MediaType; 025import org.springframework.lang.Nullable; 026import org.springframework.oxm.Marshaller; 027import org.springframework.oxm.Unmarshaller; 028import org.springframework.util.Assert; 029 030/** 031 * Implementation of {@link org.springframework.http.converter.HttpMessageConverter HttpMessageConverter} 032 * that can read and write XML using Spring's {@link Marshaller} and {@link Unmarshaller} abstractions. 033 * 034 * <p>This converter requires a {@code Marshaller} and {@code Unmarshaller} before it can be used. 035 * These can be injected by the {@linkplain #MarshallingHttpMessageConverter(Marshaller) constructor} 036 * or {@linkplain #setMarshaller(Marshaller) bean properties}. 037 * 038 * <p>By default, this converter supports {@code text/xml} and {@code application/xml}. This can be 039 * overridden by setting the {@link #setSupportedMediaTypes(java.util.List) supportedMediaTypes} property. 040 * 041 * @author Arjen Poutsma 042 * @since 3.0 043 */ 044public class MarshallingHttpMessageConverter extends AbstractXmlHttpMessageConverter<Object> { 045 046 @Nullable 047 private Marshaller marshaller; 048 049 @Nullable 050 private Unmarshaller unmarshaller; 051 052 053 /** 054 * Construct a new {@code MarshallingHttpMessageConverter} with no {@link Marshaller} or 055 * {@link Unmarshaller} set. The Marshaller and Unmarshaller must be set after construction 056 * by invoking {@link #setMarshaller(Marshaller)} and {@link #setUnmarshaller(Unmarshaller)}. 057 */ 058 public MarshallingHttpMessageConverter() { 059 } 060 061 /** 062 * Construct a new {@code MarshallingMessageConverter} with the given {@link Marshaller} set. 063 * <p>If the given {@link Marshaller} also implements the {@link Unmarshaller} interface, 064 * it is used for both marshalling and unmarshalling. Otherwise, an exception is thrown. 065 * <p>Note that all {@code Marshaller} implementations in Spring also implement the 066 * {@code Unmarshaller} interface, so that you can safely use this constructor. 067 * @param marshaller object used as marshaller and unmarshaller 068 */ 069 public MarshallingHttpMessageConverter(Marshaller marshaller) { 070 Assert.notNull(marshaller, "Marshaller must not be null"); 071 this.marshaller = marshaller; 072 if (marshaller instanceof Unmarshaller) { 073 this.unmarshaller = (Unmarshaller) marshaller; 074 } 075 } 076 077 /** 078 * Construct a new {@code MarshallingMessageConverter} with the given 079 * {@code Marshaller} and {@code Unmarshaller}. 080 * @param marshaller the Marshaller to use 081 * @param unmarshaller the Unmarshaller to use 082 */ 083 public MarshallingHttpMessageConverter(Marshaller marshaller, Unmarshaller unmarshaller) { 084 Assert.notNull(marshaller, "Marshaller must not be null"); 085 Assert.notNull(unmarshaller, "Unmarshaller must not be null"); 086 this.marshaller = marshaller; 087 this.unmarshaller = unmarshaller; 088 } 089 090 091 /** 092 * Set the {@link Marshaller} to be used by this message converter. 093 */ 094 public void setMarshaller(Marshaller marshaller) { 095 this.marshaller = marshaller; 096 } 097 098 /** 099 * Set the {@link Unmarshaller} to be used by this message converter. 100 */ 101 public void setUnmarshaller(Unmarshaller unmarshaller) { 102 this.unmarshaller = unmarshaller; 103 } 104 105 106 @Override 107 public boolean canRead(Class<?> clazz, @Nullable MediaType mediaType) { 108 return (canRead(mediaType) && this.unmarshaller != null && this.unmarshaller.supports(clazz)); 109 } 110 111 @Override 112 public boolean canWrite(Class<?> clazz, @Nullable MediaType mediaType) { 113 return (canWrite(mediaType) && this.marshaller != null && this.marshaller.supports(clazz)); 114 } 115 116 @Override 117 protected boolean supports(Class<?> clazz) { 118 // should not be called, since we override canRead()/canWrite() 119 throw new UnsupportedOperationException(); 120 } 121 122 @Override 123 protected Object readFromSource(Class<?> clazz, HttpHeaders headers, Source source) throws Exception { 124 Assert.notNull(this.unmarshaller, "Property 'unmarshaller' is required"); 125 Object result = this.unmarshaller.unmarshal(source); 126 if (!clazz.isInstance(result)) { 127 throw new TypeMismatchException(result, clazz); 128 } 129 return result; 130 } 131 132 @Override 133 protected void writeToResult(Object o, HttpHeaders headers, Result result) throws Exception { 134 Assert.notNull(this.marshaller, "Property 'marshaller' is required"); 135 this.marshaller.marshal(o, result); 136 } 137 138}