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DATAJPA-1449 - Polishing.

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Removed Specification.EMPTY_SPEC. Add nullable annotations where needed. Removed CompositionType in favor of explicit lambda.
This commit is contained in:
Oliver Drotbohm
2018-12-04 14:30:16 +01:00
parent d6250dc949
commit 25924d8994
2 changed files with 58 additions and 49 deletions
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25
src/main/java/org/springframework/data/jpa/domain/Specification.java
View File

@@ -16,7 +16,6 @@
package org.springframework.data.jpa.domain;
import static org.springframework.data.jpa.domain.SpecificationComposition.*;
import static org.springframework.data.jpa.domain.SpecificationComposition.CompositionType.*;
import java.io.Serializable;
@@ -40,8 +39,6 @@ public interface Specification<T> extends Serializable {
long serialVersionUID = 1L;
Specification EMPTY_SPEC = (root, query, criteriaBuilder) -> null;
/**
* Negates the given {@link Specification}.
*
@@ -50,8 +47,11 @@ public interface Specification<T> extends Serializable {
* @return
* @since 2.0
*/
static <T> Specification<T> not(Specification<T> spec) {
return negated(spec);
static <T> Specification<T> not(@Nullable Specification<T> spec) {
return spec == null //
? (root, query, builder) -> null//
: (root, query, builder) -> builder.not(spec.toPredicate(root, query, builder));
}
/**
@@ -62,8 +62,9 @@ public interface Specification<T> extends Serializable {
* @return
* @since 2.0
*/
static <T> Specification<T> where(Specification<T> spec) {
return spec == null ? EMPTY_SPEC : spec;
@Nullable
static <T> Specification<T> where(@Nullable Specification<T> spec) {
return spec == null ? (root, query, builder) -> null : spec;
}
/**
@@ -73,8 +74,9 @@ public interface Specification<T> extends Serializable {
* @return The conjunction of the specifications
* @since 2.0
*/
default Specification<T> and(Specification<T> other) {
return composed(this, other, AND);
@Nullable
default Specification<T> and(@Nullable Specification<T> other) {
return composed(this, other, (builder, left, rhs) -> builder.and(left, rhs));
}
/**
@@ -84,8 +86,9 @@ public interface Specification<T> extends Serializable {
* @return The disjunction of the specifications
* @since 2.0
*/
default Specification<T> or(Specification<T> other) {
return composed(this, other, OR);
@Nullable
default Specification<T> or(@Nullable Specification<T> other) {
return composed(this, other, (builder, left, rhs) -> builder.or(left, rhs));
}
/**

82
src/main/java/org/springframework/data/jpa/domain/SpecificationComposition.java
View File

@@ -1,56 +1,62 @@
/*
* Copyright 2018 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.jpa.domain;
import java.io.Serializable;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import org.springframework.lang.Nullable;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.Predicate;
/**
* Helper class to support specification compositions
* Helper class to support specification compositions.
*
* @author Sebastian Staudt
* @author Oliver Gierke
* @see Specification
* @since 2.2
*/
class SpecificationComposition {
/**
* Enum for the composition types for {@link Predicate}s. Can not be turned into lambdas as we need to be
* serializable.
*
* @author Thomas Darimont
*/
enum CompositionType {
interface Combiner extends Serializable {
Predicate combine(CriteriaBuilder builder, @Nullable Predicate lhs, @Nullable Predicate rhs);
}
AND {
@Override
public Predicate combine(CriteriaBuilder builder, Predicate lhs, Predicate rhs) {
return builder.and(lhs, rhs);
}
},
@Nullable
static <T> Specification<T> composed(@Nullable Specification<T> lhs, @Nullable Specification<T> rhs,
Combiner combiner) {
OR {
@Override
public Predicate combine(CriteriaBuilder builder, Predicate lhs, Predicate rhs) {
return builder.or(lhs, rhs);
}
};
return (root, query, builder) -> {
abstract Predicate combine(CriteriaBuilder builder, Predicate lhs, Predicate rhs);
}
Predicate otherPredicate = toPredicate(lhs, root, query, builder);
Predicate thisPredicate = toPredicate(rhs, root, query, builder);
static <T> Specification<T> negated(@Nullable Specification<T> spec) {
return (root, query, builder) -> spec == null ? null : builder.not(spec.toPredicate(root, query, builder));
}
if (thisPredicate == null) {
return otherPredicate;
}
static <T> Specification<T> composed(@Nullable Specification<T> lhs, @Nullable Specification<T> rhs, CompositionType compositionType) {
return otherPredicate == null ? thisPredicate : combiner.combine(builder, thisPredicate, otherPredicate);
};
}
return (root, query, builder) -> {
Predicate otherPredicate = rhs == null ? null : rhs.toPredicate(root, query, builder);
Predicate thisPredicate = lhs == null ? null : lhs.toPredicate(root, query, builder);
return thisPredicate == null ? otherPredicate
: otherPredicate == null ? thisPredicate : compositionType.combine(builder, thisPredicate, otherPredicate);
};
}
private static <T> Predicate toPredicate(Specification<T> specification, Root<T> root, CriteriaQuery<?> query,
CriteriaBuilder builder) {
return specification == null ? null : specification.toPredicate(root, query, builder);
}
}