org.springframework.web.servlet.mvc.method.annotation.PathVariableMethodArgumentResolver Maven / Gradle / Ivy
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* Copyright 2002-2023 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
*
* https://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.method.annotation;
import java.beans.PropertyEditor;
import java.util.HashMap;
import java.util.Map;
import org.springframework.core.MethodParameter;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.TypeDescriptor;
import org.springframework.core.convert.converter.Converter;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.MissingPathVariableException;
import org.springframework.web.bind.ServletRequestBindingException;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.ValueConstants;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;
import org.springframework.web.method.support.UriComponentsContributor;
import org.springframework.web.servlet.HandlerMapping;
import org.springframework.web.servlet.View;
import org.springframework.web.util.UriComponentsBuilder;
/**
* Resolves method arguments annotated with an @{@link PathVariable}.
*
* An @{@link PathVariable} is a named value that gets resolved from a URI template variable.
* It is always required and does not have a default value to fall back on. See the base class
* {@link org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver}
* for more information on how named values are processed.
*
*
If the method parameter type is {@link Map}, the name specified in the annotation is used
* to resolve the URI variable String value. The value is then converted to a {@link Map} via
* type conversion, assuming a suitable {@link Converter} or {@link PropertyEditor} has been
* registered.
*
*
A {@link WebDataBinder} is invoked to apply type conversion to resolved path variable
* values that don't yet match the method parameter type.
*
* @author Rossen Stoyanchev
* @author Arjen Poutsma
* @author Juergen Hoeller
* @since 3.1
*/
public class PathVariableMethodArgumentResolver extends AbstractNamedValueMethodArgumentResolver
implements UriComponentsContributor {
private static final TypeDescriptor STRING_TYPE_DESCRIPTOR = TypeDescriptor.valueOf(String.class);
@Override
public boolean supportsParameter(MethodParameter parameter) {
if (!parameter.hasParameterAnnotation(PathVariable.class)) {
return false;
}
if (Map.class.isAssignableFrom(parameter.nestedIfOptional().getNestedParameterType())) {
PathVariable pathVariable = parameter.getParameterAnnotation(PathVariable.class);
return (pathVariable != null && StringUtils.hasText(pathVariable.value()));
}
return true;
}
@Override
protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) {
PathVariable ann = parameter.getParameterAnnotation(PathVariable.class);
Assert.state(ann != null, "No PathVariable annotation");
return new PathVariableNamedValueInfo(ann);
}
@Override
@SuppressWarnings("unchecked")
@Nullable
protected Object resolveName(String name, MethodParameter parameter, NativeWebRequest request) throws Exception {
Map uriTemplateVars = (Map) request.getAttribute(
HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, RequestAttributes.SCOPE_REQUEST);
return (uriTemplateVars != null ? uriTemplateVars.get(name) : null);
}
@Override
protected void handleMissingValue(String name, MethodParameter parameter) throws ServletRequestBindingException {
throw new MissingPathVariableException(name, parameter);
}
@Override
protected void handleMissingValueAfterConversion(
String name, MethodParameter parameter, NativeWebRequest request) throws Exception {
throw new MissingPathVariableException(name, parameter, true);
}
@Override
@SuppressWarnings("unchecked")
protected void handleResolvedValue(@Nullable Object arg, String name, MethodParameter parameter,
@Nullable ModelAndViewContainer mavContainer, NativeWebRequest request) {
String key = View.PATH_VARIABLES;
int scope = RequestAttributes.SCOPE_REQUEST;
Map pathVars = (Map) request.getAttribute(key, scope);
if (pathVars == null) {
pathVars = new HashMap<>();
request.setAttribute(key, pathVars, scope);
}
pathVars.put(name, arg);
}
@Override
public void contributeMethodArgument(MethodParameter parameter, Object value,
UriComponentsBuilder builder, Map uriVariables, ConversionService conversionService) {
if (Map.class.isAssignableFrom(parameter.nestedIfOptional().getNestedParameterType())) {
return;
}
PathVariable ann = parameter.getParameterAnnotation(PathVariable.class);
String name = (ann != null && StringUtils.hasLength(ann.value()) ? ann.value() : parameter.getParameterName());
String formatted = formatUriValue(conversionService, new TypeDescriptor(parameter.nestedIfOptional()), value);
uriVariables.put(name, formatted);
}
@Nullable
protected String formatUriValue(@Nullable ConversionService cs, @Nullable TypeDescriptor sourceType, Object value) {
if (value instanceof String string) {
return string;
}
else if (cs != null) {
return (String) cs.convert(value, sourceType, STRING_TYPE_DESCRIPTOR);
}
else {
return value.toString();
}
}
private static class PathVariableNamedValueInfo extends NamedValueInfo {
public PathVariableNamedValueInfo(PathVariable annotation) {
super(annotation.name(), annotation.required(), ValueConstants.DEFAULT_NONE);
}
}
}