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.messaging.converter; 018 019import org.springframework.messaging.MessageHeaders; 020import org.springframework.util.MimeType; 021 022/** 023 * A default {@link ContentTypeResolver} that checks the 024 * {@link MessageHeaders#CONTENT_TYPE} header or falls back to a default value. 025 * 026 * <p>The header value is expected to be a {@link org.springframework.util.MimeType} 027 * or a {@code String} that can be parsed into a {@code MimeType}. 028 * 029 * @author Rossen Stoyanchev 030 * @since 4.0 031 */ 032public class DefaultContentTypeResolver implements ContentTypeResolver { 033 034 private MimeType defaultMimeType; 035 036 037 /** 038 * Set the default MIME type to use when there is no 039 * {@link MessageHeaders#CONTENT_TYPE} header present. 040 * <p>This property does not have a default value. 041 */ 042 public void setDefaultMimeType(MimeType defaultMimeType) { 043 this.defaultMimeType = defaultMimeType; 044 } 045 046 /** 047 * Return the default MIME type to use if no 048 * {@link MessageHeaders#CONTENT_TYPE} header is present. 049 */ 050 public MimeType getDefaultMimeType() { 051 return this.defaultMimeType; 052 } 053 054 055 @Override 056 public MimeType resolve(MessageHeaders headers) { 057 if (headers == null || headers.get(MessageHeaders.CONTENT_TYPE) == null) { 058 return this.defaultMimeType; 059 } 060 Object value = headers.get(MessageHeaders.CONTENT_TYPE); 061 if (value instanceof MimeType) { 062 return (MimeType) value; 063 } 064 else if (value instanceof String) { 065 return MimeType.valueOf((String) value); 066 } 067 else { 068 throw new IllegalArgumentException( 069 "Unknown type for contentType header value: " + value.getClass()); 070 } 071 } 072 073 @Override 074 public String toString() { 075 return "DefaultContentTypeResolver[" + "defaultMimeType=" + this.defaultMimeType + "]"; 076 } 077 078}