QueryDsl怎么在springData中使用

本篇文章为大家展示了QueryDsl怎么在springData中使用，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。

1.pom.xml

<projectxmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.exam</groupId>
<artifactId>testjava</artifactId>
<version>1.0.0</version>
<name>${project.artifactId}</name>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<spring.version>4.2.5.RELEASE</spring.version>
<spring-data.version>Hopper-SR1</spring-data.version>
<querydsl.version>4.1.1</querydsl.version>
<hibernate.version>5.1.0.Final</hibernate.version>
<tomcat.version>8.0.32</tomcat.version>
<logback.version>1.1.7</logback.version>
<mysql.version>5.1.33</mysql.version>
<junit.version>4.12</junit.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-framework-bom</artifactId>
<version>${spring.version}</version>
<scope>import</scope>
<type>pom</type>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-releasetrain</artifactId>
<version>${spring-data.version}</version>
<scope>import</scope>
<type>pom</type>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>com.mysema.maven</groupId>
<artifactId>maven-apt-plugin</artifactId>
<version>1.0.4</version>
<executions>
<execution>
<phase>generate-sources</phase>
<goals>
<goal>process</goal>
</goals>
<configuration>
<outputDirectory>target/generated-sources</outputDirectory>
<processor>com.querydsl.apt.jpa.JPAAnnotationProcessor</processor>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-mongodb</artifactId>
</dependency>
<dependency>
<groupId>com.querydsl</groupId>
<artifactId>querydsl-apt</artifactId>
<version>${querydsl.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.querydsl</groupId>
<artifactId>querydsl-jpa</artifactId>
<version>${querydsl.version}</version>
</dependency>
<dependency>
<groupId>com.querydsl</groupId>
<artifactId>querydsl-mongodb</artifactId>
<version>${querydsl.version}</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-jdbc</artifactId>
<version>${tomcat.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>${logback.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
</dependency>
</dependencies>

<repositories>
<repository>
<id>central</id>
<name>CentralRepository</name>
<url>http://repo1.maven.org/maven2</url>
<layout>default</layout>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
</project>

2.Domain类

packageorg.exam.domain;

importorg.springframework.data.mongodb.core.mapping.Document;
importjavax.persistence.Column;
importjavax.persistence.Entity;
importjavax.persistence.Id;
importjava.io.Serializable;

@Entity
@Document
publicclassEmployeeimplementsSerializable{
@Id
@Column(length=38)
privateStringid;
@Column(length=32)
privateStringname;
privatelongsalary;
privatelongdepartmentId;
//setter和getter略
}

3.Repository类

packageorg.exam.repository.jpa;
importorg.exam.domain.Employee;
importorg.springframework.data.querydsl.QueryDslPredicateExecutor;
importorg.springframework.data.repository.PagingAndSortingRepository;
importjava.util.Collection;
publicinterfaceJpaEmployeeRepositoryextendsPagingAndSortingRepository<Employee,String>,QueryDslPredicateExecutor<Employee>{
Collection<Employee>findByIdIn(Collection<String>ids);
}

packageorg.exam.repository.mongo;

importorg.exam.domain.Employee;
importorg.springframework.data.querydsl.QueryDslPredicateExecutor;
importorg.springframework.data.repository.PagingAndSortingRepository;
importjava.util.Collection;
publicinterfaceMongoEmployeeRepositoryextendsPagingAndSortingRepository<Employee,String>,QueryDslPredicateExecutor<Employee>{
Collection<Employee>findByIdIn(Collection<String>ids);
}

JPA有JpaRepository,MongoDB有MongoRepository,它俩都继承PagingAndSortingRepository

3.配置类

packageorg.exam.config;

importcom.mongodb.MongoClient;
importcom.mongodb.WriteConcern;
importorg.apache.tomcat.jdbc.pool.DataSource;
importorg.springframework.context.annotation.Bean;
importorg.springframework.context.annotation.Configuration;
importorg.springframework.context.annotation.PropertySource;
importorg.springframework.core.env.Environment;
importorg.springframework.data.jpa.repository.config.EnableJpaRepositories;
importorg.springframework.data.mongodb.MongoDbFactory;
importorg.springframework.data.mongodb.core.MongoTemplate;
importorg.springframework.data.mongodb.core.SimpleMongoDbFactory;
importorg.springframework.data.mongodb.core.WriteResultChecking;
importorg.springframework.data.mongodb.repository.config.EnableMongoRepositories;
importorg.springframework.orm.jpa.JpaTransactionManager;
importorg.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
importorg.springframework.orm.jpa.vendor.Database;
importorg.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
importorg.springframework.transaction.PlatformTransactionManager;
importorg.springframework.transaction.annotation.EnableTransactionManagement;

importjavax.annotation.Resource;
importjava.net.UnknownHostException;
importjava.util.Properties;

@Configuration
@PropertySource("classpath:config.properties")
@EnableTransactionManagement
@EnableJpaRepositories(basePackages="org.exam.repository.jpa")
@EnableMongoRepositories(basePackages="org.exam.repository.mongo")
publicclassAppConfig{
@Resource
privateEnvironmentenv;

@Bean(destroyMethod="close")
publicDataSourcedataSource(){
DataSourcedataSource=newDataSource();
dataSource.setDriverClassName(env.getProperty("ds.driverClassName"));
dataSource.setUrl(env.getProperty("ds.url"));
dataSource.setUsername(env.getProperty("ds.username"));
dataSource.setPassword(env.getProperty("ds.password"));
dataSource.setInitialSize(env.getProperty("ds.initialSize",Integer.class));
dataSource.setMinIdle(env.getProperty("ds.minIdle",Integer.class));
dataSource.setMaxIdle(env.getProperty("ds.maxIdle",Integer.class));
dataSource.setMaxActive(env.getProperty("ds.maxActive",Integer.class));
returndataSource;
}

@Bean
publicLocalContainerEntityManagerFactoryBeanentityManagerFactory(){
HibernateJpaVendorAdapterjpaVendorAdapter=newHibernateJpaVendorAdapter();
jpaVendorAdapter.setDatabase(Database.valueOf(env.getProperty("jpa.database")));
jpaVendorAdapter.setGenerateDdl(env.getProperty("jpa.generateDdl",Boolean.class));
jpaVendorAdapter.setShowSql(env.getProperty("jpa.showSql",Boolean.class));
LocalContainerEntityManagerFactoryBeanemf=newLocalContainerEntityManagerFactoryBean();
emf.setDataSource(dataSource());
emf.setPackagesToScan("org.exam.domain");
emf.setJpaVendorAdapter(jpaVendorAdapter);
Propertiesproperties=newProperties();
properties.setProperty("hibernate.default_schema",env.getProperty("jpa.defaultSchema"));
emf.setJpaProperties(properties);
returnemf;
}

@Bean
publicPlatformTransactionManagertransactionManager(){
returnnewJpaTransactionManager(entityManagerFactory().getObject());
}

@Bean
publicMongoDbFactorymongoDbFactory()throwsUnknownHostException{
returnnewSimpleMongoDbFactory(newMongoClient(env.getProperty("mongo.host"),env.getProperty("mongo.port",Integer.class)),env.getProperty("mongo.db"));
}

@Bean
publicMongoTemplatemongoTemplate()throwsUnknownHostException{
MongoTemplatemongoTemplate=newMongoTemplate(mongoDbFactory());
mongoTemplate.setWriteResultChecking(WriteResultChecking.EXCEPTION);
mongoTemplate.setWriteConcern(WriteConcern.NORMAL);
returnmongoTemplate;
}
}

4.测试类

packageorg.exam.repository.jpa;

importorg.exam.config.AppConfig;
importorg.exam.domain.Employee;
importorg.junit.Test;
importorg.junit.runner.RunWith;
importorg.springframework.beans.factory.annotation.Autowired;
importorg.springframework.data.domain.Page;
importorg.springframework.data.domain.PageRequest;
importorg.springframework.test.annotation.Rollback;
importorg.springframework.test.context.ContextConfiguration;
importorg.springframework.test.context.junit4.SpringJUnit4ClassRunner;
importorg.springframework.test.context.support.AnnotationConfigContextLoader;
importorg.springframework.transaction.annotation.Transactional;

importjava.util.UUID;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader=AnnotationConfigContextLoader.class,classes={AppConfig.class})
@Transactional(transactionManager="transactionManager")//Rollback默认为true
publicclassJpaEmployeeRepositoryTest{
@Autowired
privateJpaEmployeeRepositoryjpaEmployeeRepository;

@Test
@Rollback(false)
publicvoidtestSave(){
for(inti=0;i<5;i++){
Employeeemployee=newEmployee();
employee.setId(UUID.randomUUID().toString());
employee.setName("name");
employee.setDepartmentId(1+i);
employee.setSalary(6800+i);
jpaEmployeeRepository.save(employee);
}
}

@Test
publicvoidtestFindAll(){
Page<Employee>all=jpaEmployeeRepository.findAll(null,newPageRequest(0,8));
for(Employeeemployee:all){
System.out.println("employee="+employee);
}
}
}

packageorg.exam.repository.mongo;
importcom.mongodb.MongoClient;
importorg.exam.config.AppConfig;
importorg.exam.domain.Employee;
importorg.junit.Test;
importorg.junit.runner.RunWith;
importorg.springframework.beans.factory.annotation.Autowired;
importorg.springframework.data.domain.Page;
importorg.springframework.data.domain.PageRequest;
importorg.springframework.data.geo.Circle;
importorg.springframework.data.mongodb.core.MongoTemplate;
importorg.springframework.test.context.ContextConfiguration;
importorg.springframework.test.context.junit4.SpringJUnit4ClassRunner;
importorg.springframework.test.context.support.AnnotationConfigContextLoader;
importjava.net.UnknownHostException;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader=AnnotationConfigContextLoader.class,classes={AppConfig.class})
publicclassMongoEmployeeRepositoryTest{
@Autowired
privateMongoEmployeeRepositorymongoEmployeeRepository;

publicstaticvoidmain(String[]args)throwsUnknownHostException{
MongoTemplatetemplate=newMongoTemplate(newMongoClient("127.0.0.1",27017),"test");
Circlecircle=newCircle(-73.99171,40.738868,0.01);

System.out.println();
}

@Test
publicvoidtestFindAll(){
Page<Employee>all=mongoEmployeeRepository.findAll(null,newPageRequest(0,8));
for(Employeeemployee:all){
System.out.println("employee="+employee);
}
}
}

5.其它config.properties,logback.xml文件不太重要,篇幅关系就省略.

源码下载

再了解一下比较大的需求,从几张表来取几个字段的数据,返回分页排序数据.

1.在AppConfig注册JPAQueryFactory Bean

@Bean
publicJPAQueryFactoryjpaQueryFactory(EntityManagerentityManager){
returnnewJPAQueryFactory(newHQLTemplates(),entityManager);
}

2.建一个DTO(数据传输对象)

publicclassUserDTO{
privateStringempName;
privateStringdeptName;
privatelongsalary;
//setter,getter略
}

3.查询例子测试

privatePage<UserDTO>findAll(StringempName,Pageablepageable){
QEmployeeqEmp=QEmployee.employee;
QDepartmentqDep=QDepartment.department;
List<Predicate>criteria=newArrayList<>();
if(StringUtils.hasText(empName)){
criteria.add(qEmp.name.eq(empName.trim()));
}

JPAQuery<?>query=jpaQueryFactory.from(qEmp).innerJoin(qDep).on(qEmp.deptId.eq(qDep.id)).where(criteria.toArray(newPredicate[criteria.size()]));
longtotal=query.fetchCount();
List<UserDTO>content;
if(pageable==null||total>pageable.getOffset()){
Map<String,SimpleExpression<?>>map=newHashMap<>();
map.put("deptName",qDep.name);
map.put("empName",qEmp.name);
map.put("salary",qEmp.salary);
content=QuerydslUtils.applyPagination(pageable,query).select(Projections.bean(UserDTO.class,map)).fetch();
}else{
content=Collections.emptyList();
}
returnnewPageImpl<>(content,pageable,total);
}

@Test
publicvoidtest(){
Pageablepageable=newPageRequest(0,10,newQSort(newOrderSpecifier<>(Order.DESC,QEmployee.employee.salary),newOrderSpecifier<>(Order.ASC,QDepartment.department.name)));
Page<UserDTO>page=findAll("name",pageable);
for(UserDTOuserDTO:page){
System.out.println("userDTO="+userDTO);
}
}

上述内容就是QueryDsl怎么在springData中使用，你们学到知识或技能了吗？如果还想学到更多技能或者丰富自己的知识储备，欢迎关注恰卡编程网行业资讯频道。