org.springframework.data.repository.support.MethodParameters Maven / Gradle / Ivy
/*
* Copyright 2012-2019 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.data.repository.support;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;
import org.springframework.core.DefaultParameterNameDiscoverer;
import org.springframework.core.MethodParameter;
import org.springframework.core.ParameterNameDiscoverer;
import org.springframework.data.util.Lazy;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
/**
* Value object to represent {@link MethodParameters} to allow to easily find the ones with a given annotation.
*
* @author Oliver Gierke
* @author Christoph Strobl
* @since 1.10
*/
class MethodParameters {
private final ParameterNameDiscoverer discoverer = new DefaultParameterNameDiscoverer();
private final List parameters;
/**
* Creates a new {@link MethodParameters} from the given {@link Method}.
*
* @param method must not be {@literal null}.
*/
public MethodParameters(Method method) {
this(method, Optional.empty());
}
/**
* Creates a new {@link MethodParameters} for the given {@link Method} and {@link AnnotationAttribute}. If the latter
* is given, method parameter names will be looked up from the annotation attribute if present.
*
* @param method must not be {@literal null}.
* @param namingAnnotation must not be {@literal null}.
*/
public MethodParameters(Method method, Optional namingAnnotation) {
Assert.notNull(method, "Method must not be null!");
this.parameters = new ArrayList<>();
for (int i = 0; i < method.getParameterCount(); i++) {
MethodParameter parameter = new AnnotationNamingMethodParameter(method, i, namingAnnotation);
parameter.initParameterNameDiscovery(discoverer);
parameters.add(parameter);
}
}
/**
* Returns all {@link MethodParameter}s.
*
* @return
*/
public List getParameters() {
return parameters;
}
/**
* Returns the {@link MethodParameter} with the given name or {@literal null} if none found.
*
* @param name must not be {@literal null} or empty.
* @return
*/
public Optional getParameter(String name) {
Assert.hasText(name, "Parameter name must not be null!");
return getParameters().stream()//
.filter(it -> name.equals(it.getParameterName())).findFirst();
}
/**
* Returns all parameters of the given type.
*
* @param type must not be {@literal null}.
* @return
* @since 0.9
*/
public List getParametersOfType(Class type) {
Assert.notNull(type, "Type must not be null!");
return getParameters().stream()//
.filter(it -> it.getParameterType().equals(type))//
.collect(Collectors.toList());
}
/**
* Returns all {@link MethodParameter}s annotated with the given annotation type.
*
* @param annotation must not be {@literal null}.
* @return
*/
public List getParametersWith(Class annotation) {
Assert.notNull(annotation, "Annotation must not be null!");
return getParameters().stream()//
.filter(it -> it.hasParameterAnnotation(annotation))//
.collect(Collectors.toList());
}
/**
* Custom {@link MethodParameter} extension that will favor the name configured in the {@link AnnotationAttribute} if
* set over discovering it.
*
* @author Oliver Gierke
*/
private static class AnnotationNamingMethodParameter extends MethodParameter {
private final Optional attribute;
private final Lazy name;
/**
* Creates a new {@link AnnotationNamingMethodParameter} for the given {@link Method}'s parameter with the given
* index.
*
* @param method must not be {@literal null}.
* @param parameterIndex
* @param attribute can be {@literal null}
*/
public AnnotationNamingMethodParameter(Method method, int parameterIndex, Optional attribute) {
super(method, parameterIndex);
this.attribute = attribute;
this.name = Lazy.of(() -> this.attribute.//
flatMap(it -> it.getValueFrom(this).map(Object::toString)).//
orElseGet(super::getParameterName));
}
/*
* (non-Javadoc)
* @see org.springframework.core.MethodParameter#getParameterName()
*/
@Nullable
@Override
public String getParameterName() {
return name.orElse(null);
}
}
}