实现JPA和Spring Boot的搜索功能
我正在尝试为数据库表实现正确的搜索功能。我尝试了这种方法：
控制器：
@GetMapping public Page<TransactionDTO> find(TransactionFilterDTO filter, Pageable page) {
return searchRepository
.findTransactionsByFilter(mapper.toFilter(filter), page)
.map(mapper::toDTO);
}
Filer DTO：
public class TransactionFilterDTO { private String name;
private Integer id;
@DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
private LocalDateTime from;
@DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
private LocalDateTime to;
... // getters and setter
}
搜索实现：
@Repositorypublic class TransactionSearchRepositoryImpl implements TransactionSearchRepository {
@Autowired
private TransactionRepository transactionRepository;
@Autowired
private TransactionSpecification specification;
@Override
public Page<Transaction> findTransactionsByFilter(TransactionFilter filter, @Nullable Pageable page) {
List<Transaction> transactions = transactionRepository
.findAll(specification.getFilter(filter));
int totalCount = transactions.size();
if(page != null) {
transactions = transactions
.stream()
.skip(page.getOffset())
.limit(page.getPageSize())
.collect(Collectors.toList());
}
return new PageImpl<>(transactions, page, totalCount);
}
}
仓库：
public interface TransactionSearchRepository { Page<Transaction> findTransactionsByFilter(TransactionFilter filter, Pageable page);
}
有没有更好的方法来实现搜索功能？我认为这种解决方案非常难看。
回答：
我可以推荐几种解决此任务的方法：
1）简单的，但不灵活：在控制器中使用刚请求参数根据自己的滤波器特性（name，from，to），并且在回购制备相应的查询，例如：
控制器：
@GetMapping("/q")public List<ResponseDto> getAllByQuery(
@RequestParam(value = "name", required = false) String name,
@RequestParam(value = "from", required = false) @DateTimeFormat(iso = ISO.DATE) LocalDate from,
@RequestParam(value = "to", required = false) @DateTimeFormat(iso = ISO.DATE) LocalDate to,
Pageable pageable
) {
return service.getByQuery(name, from, to, pageable);
}
服务：
public Page<ResponseDto> getByQuery(String name, LocalDate from, LocalDate to, Pageable pageable) { return repo.getByQuery(name, from, to, pageable).map(mapper::toResponseDto);
}
仓库：
@Query("select m from MyEntity m where " + "(?1 is null or upper(m.name) like concat('%', upper(?1), '%')) " +
"and (?2 is null or m.createdAt >= ?2) " +
"and (?3 is null or m.createdAt <= ?3)")
Page<MyEntity> getByQuery(String name, final LocalDate from, final LocalDate to, final Pageable pageable);
然后执行一个请求：
GET http://localhost:8080/q?name=john&from=2019-04-19&to=2019-04-192）使用
。您应该将其添加到您的项目中（您可以在此处找到详细信息），从QuerydslPredicateExecutor和扩展您的仓库QuerydslBinderCustomizer，向其中添加一些“调整”：
public interface MyEntityRepo extends JpaRepository<MyEntity, Integer>, QuerydslPredicateExecutor<MyEntity>, QuerydslBinderCustomizer<QMyEntity> { @Override
default void customize(@NonNull QuerydslBindings bindings, @NonNull QMyEntity entity) {
// Make case-insensitive 'like' filter for all string properties
bindings.bind(String.class).first((SingleValueBinding<StringPath, String>) StringExpression::containsIgnoreCase);
// Add 'between' and 'greater or equal' filter date property
bindings.bind(entity.createdAt).all((path, value) -> {
Iterator<? extends LocalDate> it = value.iterator();
LocalDate from = it.next();
if (value.size() >= 2) {
LocalDate to = it.next();
return Optional.of(path.between(from, to)); // between
} else {
return Optional.of(path.goe(from)); // greater than or equal
}
});
}
添加服务方式：
public Page<ResponseDto> getAllByQueryDsl(Predicate predicate, Pageable pageable) { return repo.findAll(predicate, pageable).map(mapper::toResponseDto);
}
添加控制器方法：
@GetMapping("/query-dsl")public Page<ResponseDto> getAllByQueryDsl(
@QuerydslPredicate(root = MyEntity.class, bindings = MyEntityRepo.class) Predicate predicate,
Pageable pageable
) {
return service.getAllByQueryDsl(predicate, pageable);
}
并将@DateTimeFormat注释添加到实体的“日期”属性中：
@Entitypublic class MyEntity {
// ...
@DateTimeFormat(iso = ISO.DATE) private LocalDate createdAt;
}
然后，您可以执行这样的请求：
GET http://localhost:8080/query-dsl?name=john&createdAt=2019-04-15&createdAt=2019-04-19其中第一个日期是“ from”参数，第二个日期是“ to”参数。如果您仅使用一个日期-它将是’from’参数（大于或等于）。
3）使用
库。将其添加到您的项目中（请参阅说明：1和2），然后从JpaSpecificationExecutor以下位置扩展您的存储库：
public interface MyEntityRepo extends JpaRepository<MyEntity, Integer>, JpaSpecificationExecutor<MyEntity> {}将这样的方法添加到您的控制器中：
@GetMapping("/specification")public Page<ResponseDto> getAllBySpecification(
@And({
@Spec(path = "name", spec = LikeIgnoreCase.class),
@Spec(path = "createdAt", params = "from", spec = GreaterThanOrEqual.class),
@Spec(path = "createdAt", params = "to", spec = LessThanOrEqual.class)
}) Specification<MyEntity> specification,
Pageable pageable
) {
return service.getAllBySpecification(specification, pageable);
}
更新您的服务：
public Page<ResponseDto> getAllBySpecification(final Specification<MyEntity> specification, final Pageable pageable) { return repo.findAll(specification, pageable).map(mapper::toResponseDto);
}
然后请求您的数据：
GET http://localhost:8080/specification?name=john&from=2019-04-10&to=2019-04-194）手动建立规范：
创建一个过滤器类：
@Datapublic class MyFilter implements Specification<MyEntity> {
private String name;
@DateTimeFormat(iso = ISO.DATE) private LocalDate from;
@DateTimeFormat(iso = ISO.DATE) private LocalDate to;
@Override
public Predicate toPredicate(Root<MyEntity> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
List<Predicate> predicates = new ArrayList<>();
if (name != null) predicates.add(builder.like(builder.upper(root.get("name")), "%" + name.toUpperCase() + "%"));
if (from != null) predicates.add(builder.greaterThanOrEqualTo(root.get("createdAt"), from));
if (to != null) predicates.add(builder.lessThanOrEqualTo(root.get("createdAt"), to));
return builder.and(predicates.toArray(new Predicate[0]));
}
}
创建一个控制器方法：
@GetMapping("/filter")public Page<ResponseDto> getAllByMyFilter(MyFilter filter, Pageable pageable) {
return service.getAllBySpecification(filter, pageable);
}
然后运行请求：
GET http://localhost:8080/filter?name=john&from=2019-04-10&to=2019-04-19以上是 实现JPA和Spring Boot的搜索功能 的全部内容， 来源链接： utcz.com/qa/428205.html
