/*
* Copyright 2002-2011 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.servlet.mvc.condition;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import org.springframework.http.MediaType;
import org.springframework.util.StringUtils;
import org.springframework.web.HttpMediaTypeNotSupportedException;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.mvc.condition.HeadersRequestCondition.HeaderExpression;
/**
* A logical disjunction (' || ') request condition to match a request's
* 'Content-Type' header to a list of media type expressions. Two kinds of
* media type expressions are supported, which are described in
* {@link RequestMapping#consumes()} and {@link RequestMapping#headers()}
* where the header name is 'Content-Type'. Regardless of which syntax is
* used, the semantics are the same.
*
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @since 3.1
*/
public final class ConsumesRequestCondition extends AbstractRequestCondition<ConsumesRequestCondition> {
private final List<ConsumeMediaTypeExpression> expressions;
/**
* Creates a new instance from 0 or more "consumes" expressions.
* @param consumes expressions with the syntax described in
* {@link RequestMapping#consumes()}; if 0 expressions are provided,
* the condition will match to every request.
*/
public ConsumesRequestCondition(String... consumes) {
this(consumes, null);
}
/**
* Creates a new instance with "consumes" and "header" expressions.
* "Header" expressions where the header name is not 'Content-Type' or have
* no header value defined are ignored. If 0 expressions are provided in
* total, the condition will match to every request
* @param consumes as described in {@link RequestMapping#consumes()}
* @param headers as described in {@link RequestMapping#headers()}
*/
public ConsumesRequestCondition(String[] consumes, String[] headers) {
this(parseExpressions(consumes, headers));
}
/**
* Private constructor accepting parsed media type expressions.
*/
private ConsumesRequestCondition(Collection<ConsumeMediaTypeExpression> expressions) {
this.expressions = new ArrayList<ConsumeMediaTypeExpression>(expressions);
Collections.sort(this.expressions);
}
private static Set<ConsumeMediaTypeExpression> parseExpressions(String[] consumes, String[] headers) {
Set<ConsumeMediaTypeExpression> result = new LinkedHashSet<ConsumeMediaTypeExpression>();
if (headers != null) {
for (String header : headers) {
HeaderExpression expr = new HeaderExpression(header);
if ("Content-Type".equalsIgnoreCase(expr.name)) {
for (MediaType mediaType : MediaType.parseMediaTypes(expr.value)) {
result.add(new ConsumeMediaTypeExpression(mediaType, expr.isNegated));
}
}
}
}
if (consumes != null) {
for (String consume : consumes) {
result.add(new ConsumeMediaTypeExpression(consume));
}
}
return result;
}
/**
* Return the contained MediaType expressions.
*/
public Set<MediaTypeExpression> getExpressions() {
return new LinkedHashSet<MediaTypeExpression>(this.expressions);
}
/**
* Returns the media types for this condition excluding negated expressions.
*/
public Set<MediaType> getConsumableMediaTypes() {
Set<MediaType> result = new LinkedHashSet<MediaType>();
for (ConsumeMediaTypeExpression expression : this.expressions) {
if (!expression.isNegated()) {
result.add(expression.getMediaType());
}
}
return result;
}
/**
* Whether the condition has any media type expressions.
*/
public boolean isEmpty() {
return this.expressions.isEmpty();
}
@Override
protected Collection<ConsumeMediaTypeExpression> getContent() {
return this.expressions;
}
@Override
protected String getToStringInfix() {
return " || ";
}
/**
* Returns the "other" instance if it has any expressions; returns "this"
* instance otherwise. Practically that means a method-level "consumes"
* overrides a type-level "consumes" condition.
*/
public ConsumesRequestCondition combine(ConsumesRequestCondition other) {
return !other.expressions.isEmpty() ? other : this;
}
/**
* Checks if any of the contained media type expressions match the given
* request 'Content-Type' header and returns an instance that is guaranteed
* to contain matching expressions only. The match is performed via
* {@link MediaType#includes(MediaType)}.
*
* @param request the current request
*
* @return the same instance if the condition contains no expressions;
* or a new condition with matching expressions only;
* or {@code null} if no expressions match.
*/
public ConsumesRequestCondition getMatchingCondition(HttpServletRequest request) {
if (isEmpty()) {
return this;
}
Set<ConsumeMediaTypeExpression> result = new LinkedHashSet<ConsumeMediaTypeExpression>(expressions);
for (Iterator<ConsumeMediaTypeExpression> iterator = result.iterator(); iterator.hasNext();) {
ConsumeMediaTypeExpression expression = iterator.next();
if (!expression.match(request)) {
iterator.remove();
}
}
return (result.isEmpty()) ? null : new ConsumesRequestCondition(result);
}
/**
* Returns:
* <ul>
* <li>0 if the two conditions have the same number of expressions
* <li>Less than 0 if "this" has more or more specific media type expressions
* <li>Greater than 0 if "other" has more or more specific media type expressions
* </ul>
*
* <p>It is assumed that both instances have been obtained via
* {@link #getMatchingCondition(HttpServletRequest)} and each instance contains
* the matching consumable media type expression only or is otherwise empty.
*/
public int compareTo(ConsumesRequestCondition other, HttpServletRequest request) {
if (this.expressions.isEmpty() && other.expressions.isEmpty()) {
return 0;
}
else if (this.expressions.isEmpty()) {
return 1;
}
else if (other.expressions.isEmpty()) {
return -1;
}
else {
return this.expressions.get(0).compareTo(other.expressions.get(0));
}
}
/**
* Parses and matches a single media type expression to a request's 'Content-Type' header.
*/
static class ConsumeMediaTypeExpression extends AbstractMediaTypeExpression {
ConsumeMediaTypeExpression(String expression) {
super(expression);
}
ConsumeMediaTypeExpression(MediaType mediaType, boolean negated) {
super(mediaType, negated);
}
@Override
protected boolean matchMediaType(HttpServletRequest request) throws HttpMediaTypeNotSupportedException {
try {
MediaType contentType = StringUtils.hasLength(request.getContentType()) ?
MediaType.parseMediaType(request.getContentType()) :
MediaType.APPLICATION_OCTET_STREAM;
return getMediaType().includes(contentType);
}
catch (IllegalArgumentException ex) {
throw new HttpMediaTypeNotSupportedException(
"Can't parse Content-Type [" + request.getContentType() + "]: " + ex.getMessage());
}
}
}
}