问题描述
是否有一种通过querydsl别名对存储库查询结果进行排序的方法?
Is there a way to sort repository query results by querydsl alias?
到目前为止，我已经设法进行过滤，但是对结果进行排序时出现错误:
So far I've managed to filter, but sorting results with an error:
org.springframework.data.mapping.PropertyReferenceException: No property username found for type User!
org.springframework.data.mapping.PropertyReferenceException: No property username found for type User!
请求:
GET /users?size=1&sort=username,desc
我的休息控制器方法:
@GetMapping("/users")
public ListResult<User> getUsersInGroup(
@ApiIgnore @QuerydslPredicate(root = User.class) Predicate predicate,
Pageable pageable) {
Page<User> usersInGroup =
userRepository.findByGroup(CurrentUser.getGroup(), predicate, pageable);
return new ListResult<>(usersInGroup);
}
我的存储库:
@Override
default void customize(QuerydslBindings bindings, QUser root) {
bindings.including(root.account.login, root.account.firstName, root.account.lastName,
root.account.phoneNumber, root.account.email, root.account.postalCode, root.account.city,
root.account.address, root.account.language, root.account.presentationAlias);
bindAlias(bindings, root.account.login, "username");
}
default Page<User> findByGroup(Group group, Predicate predicate, Pageable pageable) {
BooleanExpression byGroup = QUser.user.group.eq(group);
BooleanExpression finalPredicate = byGroup.and(predicate);
return findAll(finalPredicate, pageable);
}
default void bindAlias(QuerydslBindings bindings, StringPath path, String alias) {
bindings.bind(path).as(alias).first(StringExpression::likeIgnoreCase);
}
我也尝试过基于QuerydslPredicateArgumentResolver实现自己的PageableArgumentResolver，但是其中使用的某些方法是私有程序包，所以我认为我可能走错了方向
I've also tried to implement my own PageableArgumentResolver based on QuerydslPredicateArgumentResolver, but some of the methods used there are package private so I thought maybe I am going in the wrong direction
推荐答案
我成功地创建了一个以查询根类的类类型注释的PageableArgumentResolver并将别名注册表添加到我的通用存储库接口.
I succeeded by creating a PageableArgumentResolver annotated with class type of query root class and adding alias registry to my generic repository interface.
此解决方案似乎是一种解决方法，但至少可以使用;)
This solution seems like a workaround but at least it works ;)
存储库:
public interface UserRepository extends PageableAndFilterableGenericRepository<User, QUser> {
QDSLAliasRegistry aliasRegistry = QDSLAliasRegistry.instance();
@Override
default void customize(QuerydslBindings bindings, QUser root) {
bindAlias(bindings, root.account.login, "username");
}
default void bindAlias(QuerydslBindings bindings, StringPath path, String alias) {
bindings.bind(path).as(alias).first(StringExpression::likeIgnoreCase);
aliasRegistry.register(alias, path);
}
别名注册表:
public class QDSLAliasRegistry {
private static QDSLAliasRegistry inst;
public static QDSLAliasRegistry instance() {
inst = inst == null ? new QDSLAliasRegistry() : inst;
return inst;
}
private QDSLAliasRegistry() {
registry = HashBiMap.create();
}
HashBiMap<String, Path<?>> registry;
解析器:
public class QDSLSafePageResolver implements PageableArgumentResolver {
private static final String DEFAULT_PAGE = "0";
private static final String DEFAULT_PAGE_SIZE = "20";
private static final String PAGE_PARAM = "page";
private static final String SIZE_PARAM = "size";
private static final String SORT_PARAM = "sort";
private final QDSLAliasRegistry aliasRegistry;
public QDSLSafePageResolver(QDSLAliasRegistry aliasRegistry) {
this.aliasRegistry = aliasRegistry;
}
@Override
public boolean supportsParameter(MethodParameter parameter) {
return Pageable.class.equals(parameter.getParameterType())
&& parameter.hasParameterAnnotation(QDSLPageable.class);
}
@Override
public Pageable resolveArgument(MethodParameter parameter,
ModelAndViewContainer mavContainer,
NativeWebRequest webRequest,
WebDataBinderFactory binderFactory) {
MultiValueMap<String, String> parameterMap = getParameterMap(webRequest);
final Class<?> root = parameter.getParameterAnnotation(QDSLPageable.class).root();
final ClassTypeInformation<?> typeInformation = ClassTypeInformation.from(root);
String pageStr = Optional.ofNullable(parameterMap.getFirst(PAGE_PARAM)).orElse(DEFAULT_PAGE);
String sizeStr = Optional.ofNullable(parameterMap.getFirst(SIZE_PARAM)).orElse(DEFAULT_PAGE_SIZE);
int page = Integer.parseInt(pageStr);
int size = Integer.parseInt(sizeStr);
List<String> sortStrings = parameterMap.get(SORT_PARAM);
if(sortStrings != null) {
OrderSpecifier[] specifiers = new OrderSpecifier[sortStrings.size()];
for(int i = 0; i < sortStrings.size(); i++) {
String sort = sortStrings.get(i);
String[] orderArr = sort.split(",");
Order order = orderArr.length == 1 ? Order.ASC : Order.valueOf(orderArr[1].toUpperCase());
specifiers[i] = buildOrderSpecifier(orderArr[0], order, typeInformation);
}
return new QPageRequest(page, size, specifiers);
} else {
return new QPageRequest(page, size);
}
}
private MultiValueMap<String, String> getParameterMap(NativeWebRequest webRequest) {
MultiValueMap<String, String> parameters = new LinkedMultiValueMap<String, String>();
for (Map.Entry<String, String[]> entry : webRequest.getParameterMap().entrySet()) {
parameters.put(entry.getKey(), Arrays.asList(entry.getValue()));
}
return parameters;
}
private OrderSpecifier<?> buildOrderSpecifier(String sort,
Order order,
ClassTypeInformation<?> typeInfo) {
Expression<?> sortPropertyExpression = new PathBuilderFactory().create(typeInfo.getType());
String dotPath = aliasRegistry.getDotPath(sort);
PropertyPath path = PropertyPath.from(dotPath, typeInfo);
sortPropertyExpression = Expressions.path(path.getType(), (Path<?>) sortPropertyExpression, path.toDotPath());
return new OrderSpecifier(order, sortPropertyExpression);
}
}
这篇关于如何按querydsl别名排序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！