我正在使用
Spring data jpa repositoriesEmployeeNumberNameMarriedProfessionDateOfBirthInput : EmployeeNumber: ,Name:St,Married: ,Professsion:IT,DateOfBirth:
Query : Select * from Employee e where Name like 'St%' and Profession like 'IT%';
Input : EmployeeNumber:10,Name: ,Married: ,Professsion:IT,DateOfBirth:
Query : Select * from Employee e where EmployeeNumber like '10%' and Profession like 'IT%';
所以这里我们正在考虑输入的值和查询。在这种情况下，Spring 数据存在这篇文章中提到的限制（不可扩展，应编写所有可能的查询） 我正在使用
Querydslnullcase 31 queries6,7,8...实现带有可选字段的搜索选项的最佳方法是什么？
您可以使用 Spring-data 为您提供的开箱即用的规范。并能够使用标准 API 以编程方式构建查询。要支持规范，您可以使用 JpaSpecificationExecutor 接口扩展存储库接口
public interface CustomerRepository extends SimpleJpaRepository<T, ID>, JpaSpecificationExecutor {
}
附加接口（JpaSpecificationExecutor）携带的方法允许您以多种方式执行规范。
例如，findAll方法将返回符合规范的所有实体：
List<T> findAll(Specification<T> spec);
规格界面如下：
public interface Specification<T> {
Predicate toPredicate(Root<T> root, CriteriaQuery<?> query,
CriteriaBuilder builder);
}
好的，那么典型的用例是什么？规范可以轻松地用于在实体之上构建一组可扩展的谓词，然后可以将其与 JpaRepository 组合并使用，而无需为每个所需的组合声明查询（方法）。下面是一个示例：示例 2.15。客户规格
public class CustomerSpecs {
public static Specification<Customer> isLongTermCustomer() {
return new Specification<Customer>() {
public Predicate toPredicate(
Root<Customer> root, CriteriaQuery<?> query,
CriteriaBuilder builder) {
LocalDate date = new LocalDate().minusYears(2);
return builder.lessThan(root.get('dateField'), date);
}
};
}
public static Specification<Customer> hasSalesOfMoreThan(MontaryAmount value) {
return new Specification<Customer>() {
public Predicate toPredicate(
Root<T> root, CriteriaQuery<?> query,
CriteriaBuilder builder) {
// build query here
}
};
}
}
您表达了业务需求抽象级别的一些标准并创建了可执行的规范。因此，客户可能会使用如下规范：
List customers = customerRepository.findAll(isLongTermCustomer());
您还可以结合规范示例 2.17。组合规格
MonetaryAmount amount = new MonetaryAmount(200.0, Currencies.DOLLAR);
List<Customer> customers = customerRepository.findAll(
where(isLongTermCustomer()).or(hasSalesOfMoreThan(amount)));
如您所见，规范提供了一些粘合代码方法来链接 并结合规格。因此扩展你的数据访问层是 只需创建新的规范实现即可 将它们与现有的结合起来。
您可以创建复杂的规格，这是一个示例
public class WorkInProgressSpecification {
public static Specification<WorkInProgress> findByCriteria(final SearchCriteria searchCriteria) {
return new Specification<WorkInProgress>() {
@Override
public Predicate toPredicate(
Root<WorkInProgress> root,
CriteriaQuery<?> query, CriteriaBuilder cb) {
List<Predicate> predicates = new ArrayList<Predicate>();
if (searchCriteria.getView() != null && !searchCriteria.getView().isEmpty()) {
predicates.add(cb.equal(root.get("viewType"), searchCriteria.getView()));
}
if (searchCriteria.getFeature() != null && !searchCriteria.getFeature().isEmpty()) {
predicates.add(cb.equal(root.get("title"), searchCriteria.getFeature()));
}
if (searchCriteria.getEpic() != null && !searchCriteria.getEpic().isEmpty()) {
predicates.add(cb.equal(root.get("epic"), searchCriteria.getEpic()));
}
if (searchCriteria.getPerformingGroup() != null && !searchCriteria.getPerformingGroup().isEmpty()) {
predicates.add(cb.equal(root.get("performingGroup"), searchCriteria.getPerformingGroup()));
}
if (searchCriteria.getPlannedStartDate() != null) {
System.out.println("searchCriteria.getPlannedStartDate():" + searchCriteria.getPlannedStartDate());
predicates.add(cb.greaterThanOrEqualTo(root.<Date>get("plndStartDate"), searchCriteria.getPlannedStartDate()));
}
if (searchCriteria.getPlannedCompletionDate() != null) {
predicates.add(cb.lessThanOrEqualTo(root.<Date>get("plndComplDate"), searchCriteria.getPlannedCompletionDate()));
}
if (searchCriteria.getTeam() != null && !searchCriteria.getTeam().isEmpty()) {
predicates.add(cb.equal(root.get("agileTeam"), searchCriteria.getTeam()));
}
return cb.and(predicates.toArray(new Predicate[] {}));
}
};
}
}
这里是 JPA 存储库文档
请注意，使用新的主要版本 QueryDSL (4.x) 和 querydsl-jpa
可能需要进行更改在我们的一个项目中，我们将
QueryDSLQueryDslPredicateExecutor<T> public Predicate createPredicate(DataEntity dataEntity) {
QDataEntity qDataEntity = QDataEntity.dataEntity;
BooleanBuilder booleanBuilder = new BooleanBuilder();
if (!StringUtils.isEmpty(dataEntity.getCnsiConsumerNo())) {
booleanBuilder
.or(qDataEntity.cnsiConsumerNo.contains(dataEntity.getCnsiConsumerNo()));
}
if (!StringUtils.isEmpty(dataEntity.getCnsiMeterNo())) {
booleanBuilder.or(qDataEntity.cnsiMeterNo.contains(dataEntity.getCnsiMeterNo()));
}
return booleanBuilder.getValue();
}
我们可以在存储库中使用它：
@Repository
public interface DataEntityRepository
extends DaoRepository<DataEntity, Long> {
DaoRepository@NoRepositoryBean
public interface DaoRepository<T, K extends Serializable>
extends JpaRepository<T, K>,
QueryDslPredicateExecutor<T> {
}
因为这样，您就可以使用存储库谓词方法。
Iterable<DataEntity> results = dataEntityRepository.findAll(dataEntityPredicateCreator.createPredicate(dataEntity));
要获得
QClasses <build>
<plugins>
<plugin>
<groupId>com.mysema.maven</groupId>
<artifactId>maven-apt-plugin</artifactId>
<version>1.0.4</version>
<executions>
<execution>
<phase>generate-sources</phase>
<goals>
<goal>process</goal>
</goals>
<configuration>
<outputDirectory>target/generated-sources</outputDirectory>
<processor>com.mysema.query.apt.jpa.JPAAnnotationProcessor</processor>
</configuration>
</execution>
</executions>
</plugin>
依赖关系是
<!-- querydsl -->
<dependency>
<groupId>com.mysema.querydsl</groupId>
<artifactId>querydsl-core</artifactId>
<version>${querydsl.version}</version>
</dependency>
<dependency>
<groupId>com.mysema.querydsl</groupId>
<artifactId>querydsl-apt</artifactId>
<version>${querydsl.version}</version>
</dependency>
<dependency>
<groupId>com.mysema.querydsl</groupId>
<artifactId>querydsl-jpa</artifactId>
<version>${querydsl.version}</version>
</dependency>
或者对于 Gradle：
sourceSets {
generated
}
sourceSets.generated.java.srcDirs = ['src/main/generated']
configurations {
querydslapt
}
dependencies {
// other deps ....
compile "com.mysema.querydsl:querydsl-jpa:3.6.3"
compile "com.mysema.querydsl:querydsl-apt:3.6.3:jpa"
}
task generateQueryDSL(type: JavaCompile, group: 'build', description: 'Generates the QueryDSL query types') {
source = sourceSets.main.java
classpath = configurations.compile + configurations.querydslapt
options.compilerArgs = [
"-proc:only",
"-processor", "com.mysema.query.apt.jpa.JPAAnnotationProcessor"
]
destinationDir = sourceSets.generated.java.srcDirs.iterator().next()
}
compileJava {
dependsOn generateQueryDSL
source generateQueryDSL.destinationDir
}
compileGeneratedJava {
dependsOn generateQueryDSL
classpath += sourceSets.main.runtimeClasspath
}
从 Spring Data JPA 1.10 开始，还有另一个选项是 按示例查询。 除了
JpaRepository<S extends T> Iterable<S> findAll(Example<S> example)
然后创建示例来搜索：
Employee e = new Employee();
e.setEmployeeNumber(getEmployeeNumberSomewherFrom());
e.setName(getNameSomewhereFrom());
e.setMarried(getMarriedSomewhereFrom());
e.setProfession(getProfessionSomewhereFrom());
e.setDateOfBirth(getDateOfBirthSomewhereFrom());
然后：
employeeRepository.findAll(Example.of(e));
如果某些参数为空，它们将不会被带入 WHERE 子句，以便您获得动态查询。
ExampleMatcher执行不区分大小写的
ExampleMatcherlikeExampleMatcher matcher = ExampleMatcher.matching().
withMatcher("profession", ExampleMatcher.GenericPropertyMatcher.of(ExampleMatcher.StringMatcher.CONTAINING).ignoreCase());
QBE 示例：https://github.com/spring-projects/spring-data-examples/tree/master/jpa/query-by-example
游戏有点晚了，但这里的答案过于复杂......如果您更改实体的字段怎么办？如果您想支持搜索不同的实体怎么办？
您可以使用这个库：https://github.com/turkraft/spring-filter
它可以让您运行搜索查询，例如：
/search?filter= 平均（评级） > 4.5 and 品牌名称 in（“奥迪”、“路虎”）and（年份 > 2018 或 公里< 50000）和颜色：“白色”和意外是空的
结合Spring的Pageable，你将能够使用
&page=11&size=20看看这个库：https://github.com/biagioT/jpa-search-helper，内部使用Specifications。它可能适合你。 通过这个库，您的控制器将能够接收如下请求：
curl -X GET \
'https://myexampledomain.com/persons?
firstName=Biagio
&lastName_startsWith=Toz
&birthDate_gte=19910101
&country_in=IT,FR,DE
&address_eq=Via Roma 1,Via Milano/,1,20 West/,34th Street
&company.name_in=Microsoft,Apple,Google
&company.employees_between=500,5000'
或：
curl -X POST -H "Content-type: application/json" -d '{
"filter" : {
"operator": "and", // the first filter must contain a root operator: AND, OR or NOT
"filters" : [
{
"operator": "eq",
"key": "firstName",
"value": "Biagio"
},
{
"operator": "or",
"filters": [
{
"operator": "startsWith",
"key": "lastName",
"value": "Toz",
"options": {
"ignoreCase": true
}
},
{
"operator": "endsWith",
"key": "lastName",
"value": "ZZI",
"options": {
"ignoreCase": true,
"trim" : true
}
}
]
},
{
"operator": "in",
"key": "company.name",
"values": ["Microsoft", "Apple", "Google"]
},
{
"operator": "or",
"filters": [
{
"operator": "gte",
"key": "birthDate",
"value": "19910101"
},
{
"operator": "lte",
"key": "birthDate",
"value": "20010101"
}
]
},
{
"operator": "between",
"key" : "company.employees",
"values": [500, 5000],
"options": {
"negate": true
}
}
]
},
"options": {
"pageSize": 10,
"pageOffset": 0,
"sortKey": "birthDate",
"sortDesc": false
}
}' 'https://myexampledomain.com/persons'