Files
spring-hateoas/src/main/java/org/springframework/hateoas/QueryParameter.java
2020-02-11 18:05:34 +01:00

97 lines
3.0 KiB
Java

/*
* Copyright 2018-2020 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.hateoas;
import lombok.AccessLevel;
import lombok.RequiredArgsConstructor;
import lombok.Value;
import lombok.With;
import java.util.Optional;
import org.springframework.core.MethodParameter;
import org.springframework.core.annotation.MergedAnnotation;
import org.springframework.core.annotation.MergedAnnotations;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestParam;
/**
* Representation of a web request's query parameter (https://example.com?name=foo) => {"name", "foo", true}.
*
* @author Greg Turnquist
* @author Oliver Drotbohm
*/
@Value
@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
public class QueryParameter {
private final String name;
private final @Nullable @With String value;
private final boolean required;
/**
* Creates a new {@link QueryParameter} from the given {@link MethodParameter}.
*
* @param parameter must not be {@literal null}.
* @return will never be {@literal null}.
*/
public static QueryParameter of(MethodParameter parameter) {
MergedAnnotation<RequestParam> annotation = MergedAnnotations //
.from(parameter.getParameter()) //
.get(RequestParam.class);
String name = annotation.isPresent() && annotation.hasNonDefaultValue("name") //
? annotation.getString("name") //
: parameter.getParameterName();
if (name == null || !StringUtils.hasText(name)) {
throw new IllegalStateException(String.format("Couldn't determine parameter name for %s!", parameter));
}
boolean required = annotation.isPresent() && annotation.hasNonDefaultValue("required") //
? annotation.getBoolean("required") //
: !Optional.class.equals(parameter.getParameterType()); //
return required ? required(name) : optional(name);
}
/**
* Creates a new required {@link QueryParameter} with the given name;
*
* @param name must not be {@literal null} or empty.
* @return
*/
public static QueryParameter required(String name) {
Assert.hasText(name, "Name must not be null or empty!");
return new QueryParameter(name, null, true);
}
/**
* Creates a new optional {@link QueryParameter} with the given name;
*
* @param name must not be {@literal null} or empty.
* @return
*/
public static QueryParameter optional(String name) {
return new QueryParameter(name, null, false);
}
}