我想用幾個子條件實現搜索功能。我試過這個： @GetMapping("find") public Page<PaymentTransactionsDTO> getAllBySpecification( @And({ @Spec(path = "name", spec = LikeIgnoreCase.class), @Spec(path = "unique_id", spec = LikeIgnoreCase.class), @Spec(path = "createdAt", params = "from", spec = GreaterThanOrEqual.class), @Spec(path = "createdAt", params = "to", spec = LessThanOrEqual.class) }) Specification<PaymentTransactions> specification, Pageable pageable ) { return transactionService.getAllBySpecification(specification, pageable)); }存儲庫： @Override public Page<PaymentTransactions> getAllBySpecification(final Specification<PaymentTransactions> specification, final Pageable pageable) { return dao.findAll(specification, pageable); }目前此請求正在運行：GET /api/transactions/find?unique_id=22&page=0&size=10 但我也想實現這些額外的搜索條件，不僅發送基本搜索unique_id：start with =end with contains使用https://github.com/tkaczmarzyk/specification-arg-resolver有沒有辦法發送額外的子條件？我一般找不到這個問題的解決方案，發送這些值的最佳做法是什么？
1 回答
森欄
TA貢獻1810條經驗 獲得超5個贊
如果您想創建非常特殊的過濾器，我相信您應該從發明搜索界面開始。例如像這樣：
GET /models?name=eq(john smith)&createdAt=between(2019-01-01,2019-01-31)
GET /models?name=like(sm)&createdAt=from(2019-01-01)
GET /models?name=sw(john)&createdAt=to(2019-01-31)
之后，您將能夠嘗試實施它。
IMO 解決此類任務的最佳方法是使用 Spring Data JPA Specifications（和 JPA Criteria API）。例如：
1）讓我們創建一個為我們的實體Filter實現的類：SpecificationModel
@Value
public class ModelFilter implements Specification<Model> {
private String name;
private String createdAt;
@Override
public Predicate toPredicate(Root<Model> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
List<Predicate> predicates = new ArrayList<>();
// Prepare predicates and fill the list with them...
return builder.and(predicates.toArray(new Predicate[0]));
}
}
2）然后創建一個控制器方法：
@GetMapping
public List<Model> getAllByFilter(ModelFilter filter) {
return repo.findAll(filter);
}
剩下要做的就是準備我們的謂詞））
為此，我們可以先創建一個方便的“謂詞生成器”界面：
@FunctionalInterface
interface PredicateBuilder<T> {
Optional<Predicate> get(String fieldName, String value, Root<T> root, CriteriaBuilder builder);
static Matcher getMatcher(String op, String value) {
return getMatcher(op, value, "(.+)");
}
static Matcher getMatcher(String op, String value, String pattern) {
return Pattern.compile(op + "\\(" + pattern + "\\)").matcher(value);
}
}
然后嘗試制作我們的謂詞：
平等的
PredicateBuilder<Model> eq = (fieldName, value, root, cb) -> {
Matcher m = getMatcher("eq", value);
if (m.matches()) {
return Optional.of(cb.equal(cb.upper(root.get(fieldName)), m.group(1).toUpperCase()));
} else {
return Optional.empty();
}
};
喜歡
PredicateBuilder<Model> like = (fn, value, root, cb) -> {
Matcher m = getMatcher("like", value);
if (m.matches()) {
return Optional.of(cb.like(cb.upper(root.get(fn)), "%" + m.group(1).toUpperCase() + "%"));
} else {
return Optional.empty();
}
};
從...開始
PredicateBuilder<Model> sw = (fn, value, root, cb) -> {
Matcher m = getMatcher("sw", value);
if (m.matches()) {
return Optional.of(cb.like(cb.upper(root.get(fn)), m.group(1).toUpperCase() + "%"));
} else {
return Optional.empty();
}
};
之間
PredicateBuilder<Model> between = (fn, value, root, cb) -> {
Matcher m = getMatcher("between", value, "(.+)\\s*,\\s*(.+)");
if (m.matches()) {
LocalDate from = LocalDate.parse(m.group(1));
LocalDate to = LocalDate.parse(m.group(2));
return Optional.of(cb.between(root.get(fn), from, to));
} else {
return Optional.empty();
}
};
從
PredicateBuilder<Model> from = (fn, value, root, cb) -> {
Matcher m = getMatcher("from", value);
if (m.matches()) {
LocalDate from = LocalDate.parse(m.group(1));
return Optional.of(cb.greaterThanOrEqualTo(root.get(fn), from));
} else {
return Optional.empty();
}
};
至
PredicateBuilder<Model> to = (fn, value, root, cb) -> {
Matcher m = getMatcher("to", value);
if (m.matches()) {
LocalDate to = LocalDate.parse(m.group(1));
return Optional.of(cb.lessThanOrEqualTo(root.get(fn), to));
} else {
return Optional.empty();
}
};
剩下的只是完成Filter課程：
@Value
public class ModelFilter implements Specification<Model> {
private String name;
private String createdAt;
PredicateBuilder<Model> eq = ... ;
PredicateBuilder<Model> like = ... ;
PredicateBuilder<Model> sw = ... ;
PredicateBuilder<Model> between = ... ;
PredicateBuilder<Model> from = ... ;
PredicateBuilder<Model> to = ... ;
@Override
public Predicate toPredicate(Root<Model> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
List<Predicate> predicates = new ArrayList<>();
if (name != null) {
eq.get("name", name, root, builder).ifPresent(predicates::add);
like.get("name", name, root, builder).ifPresent(predicates::add);
sw.get("name", name, root, builder).ifPresent(predicates::add);
}
if (createdAt != null) {
between.get("createdAt", createdAt, root, builder).ifPresent(predicates::add);
from.get("createdAt", createdAt, root, builder).ifPresent(predicates::add);
to.get("createdAt", createdAt, root, builder).ifPresent(predicates::add);
}
return builder.and(predicates.toArray(new Predicate[0]));
}
}
當然，這只是實現的一個例子。您可以創建自己需要的規范和謂詞的實現。這里的主要內容是：
想出你的搜索界面
制定您的“過濾器”規范
準備好你需要的所有謂詞
在控制器方法中使用過濾器規范
添加回答
舉報
0/150
提交
取消