springData使用QueryDsl的示例代碼
更新時(shí)間：2019年01月11日 10:52:33 作者：xiejx618
這篇文章主要介紹了springData使用QueryDsl的示例代碼，小編覺(jué)得挺不錯(cuò)的，現(xiàn)在分享給大家，也給大家做個(gè)參考。一起跟隨小編過(guò)來(lái)看看吧
經(jīng)過(guò)多年,spring data jpa越來(lái)越完善,在版本迭代的過(guò)程中,會(huì)不斷增加功能,今天看新的reference發(fā)現(xiàn)有Querydsl.然后搜索到上面的參考資料2
無(wú)論是JpaSpecificationExecutor,還是QueryDslPredicateExecutor,它倆都提供了使用Predicate(意義相同,都是構(gòu)建where子句;類不同,javax.persistence.criteria.Predicate,com.querydsl.core.types.Predicate)去構(gòu)建查詢,使用比較方便.
關(guān)于兩者的簡(jiǎn)單使用,上面的參考資料2有介紹.文末也有總結(jié),從概括來(lái)看,我個(gè)人認(rèn)為應(yīng)傾向使用QueryDslPredicateExecutor,QueryDsl不僅適用于JPA repositories,還支持MongoDB.
下面是個(gè)例子
1.pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://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>Central Repository</name>
<url>http://repo1.maven.org/maven2</url>
<layout>default</layout>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
</project>
2.Domain類
package org.exam.domain;
import org.springframework.data.mongodb.core.mapping.Document;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import java.io.Serializable;
@Entity
@Document
public class Employee implements Serializable {
@Id
@Column(length = 38)
private String id;
@Column(length = 32)
private String name;
private long salary;
private long departmentId;
//setter和getter略
}
3.Repository類
package org.exam.repository.jpa;
import org.exam.domain.Employee;
import org.springframework.data.querydsl.QueryDslPredicateExecutor;
import org.springframework.data.repository.PagingAndSortingRepository;
import java.util.Collection;
public interface JpaEmployeeRepository extends PagingAndSortingRepository<Employee,String>,QueryDslPredicateExecutor<Employee>{
Collection<Employee> findByIdIn(Collection<String> ids);
}
package org.exam.repository.mongo;
import org.exam.domain.Employee;
import org.springframework.data.querydsl.QueryDslPredicateExecutor;
import org.springframework.data.repository.PagingAndSortingRepository;
import java.util.Collection;
public interface MongoEmployeeRepository extends PagingAndSortingRepository<Employee, String>, QueryDslPredicateExecutor<Employee> {
Collection<Employee> findByIdIn(Collection<String> ids);
}
JPA有JpaRepository,MongoDB有MongoRepository,它倆都繼承PagingAndSortingRepository
3.配置類
package org.exam.config;
import com.mongodb.MongoClient;
import com.mongodb.WriteConcern;
import org.apache.tomcat.jdbc.pool.DataSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.data.mongodb.MongoDbFactory;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.SimpleMongoDbFactory;
import org.springframework.data.mongodb.core.WriteResultChecking;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.Database;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import javax.annotation.Resource;
import java.net.UnknownHostException;
import java.util.Properties;
@Configuration
@PropertySource("classpath:config.properties")
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = "org.exam.repository.jpa")
@EnableMongoRepositories(basePackages = "org.exam.repository.mongo")
public class AppConfig {
@Resource
private Environment env;
@Bean(destroyMethod = "close")
public DataSource dataSource() {
DataSource dataSource = new DataSource();
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));
return dataSource;
}
@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
HibernateJpaVendorAdapter jpaVendorAdapter = new HibernateJpaVendorAdapter();
jpaVendorAdapter.setDatabase(Database.valueOf(env.getProperty("jpa.database")));
jpaVendorAdapter.setGenerateDdl(env.getProperty("jpa.generateDdl",Boolean.class));
jpaVendorAdapter.setShowSql(env.getProperty("jpa.showSql",Boolean.class));
LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
emf.setDataSource(dataSource());
emf.setPackagesToScan("org.exam.domain");
emf.setJpaVendorAdapter(jpaVendorAdapter);
Properties properties = new Properties();
properties.setProperty("hibernate.default_schema", env.getProperty("jpa.defaultSchema"));
emf.setJpaProperties(properties);
return emf;
}
@Bean
public PlatformTransactionManager transactionManager() {
return new JpaTransactionManager(entityManagerFactory().getObject());
}
@Bean
public MongoDbFactory mongoDbFactory() throws UnknownHostException {
return new SimpleMongoDbFactory(new MongoClient(env.getProperty("mongo.host"), env.getProperty("mongo.port", Integer.class)), env.getProperty("mongo.db"));
}
@Bean
public MongoTemplate mongoTemplate() throws UnknownHostException {
MongoTemplate mongoTemplate = new MongoTemplate(mongoDbFactory());
mongoTemplate.setWriteResultChecking(WriteResultChecking.EXCEPTION);
mongoTemplate.setWriteConcern(WriteConcern.NORMAL);
return mongoTemplate;
}
}
4.測(cè)試類
package org.exam.repository.jpa;
import org.exam.config.AppConfig;
import org.exam.domain.Employee;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.support.AnnotationConfigContextLoader;
import org.springframework.transaction.annotation.Transactional;
import java.util.UUID;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader = AnnotationConfigContextLoader.class, classes = {AppConfig.class})
@Transactional(transactionManager = "transactionManager")//Rollback默認(rèn)為true
public class JpaEmployeeRepositoryTest {
@Autowired
private JpaEmployeeRepository jpaEmployeeRepository;
@Test
@Rollback(false)
public void testSave() {
for (int i = 0; i < 5; i++) {
Employee employee = new Employee();
employee.setId(UUID.randomUUID().toString());
employee.setName("name");
employee.setDepartmentId(1 + i);
employee.setSalary(6800 + i);
jpaEmployeeRepository.save(employee);
}
}
@Test
public void testFindAll() {
Page<Employee> all = jpaEmployeeRepository.findAll(null, new PageRequest(0, 8));
for (Employee employee : all) {
System.out.println("employee = " + employee);
}
}
}
package org.exam.repository.mongo;
import com.mongodb.MongoClient;
import org.exam.config.AppConfig;
import org.exam.domain.Employee;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.geo.Circle;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.support.AnnotationConfigContextLoader;
import java.net.UnknownHostException;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader = AnnotationConfigContextLoader.class, classes = {AppConfig.class})
public class MongoEmployeeRepositoryTest {
@Autowired
private MongoEmployeeRepository mongoEmployeeRepository;
public static void main(String[] args) throws UnknownHostException {
MongoTemplate template = new MongoTemplate(new MongoClient("127.0.0.1", 27017), "test");
Circle circle = new Circle(-73.99171, 40.738868, 0.01);
System.out.println();
}
@Test
public void testFindAll() {
Page<Employee> all = mongoEmployeeRepository.findAll(null, new PageRequest(0, 8));
for (Employee employee : all) {
System.out.println("employee = " + employee);
}
}
}
5.其它c(diǎn)onfig.properties,logback.xml文件不太重要,篇幅關(guān)系就省略.
再了解一下比較大的需求,從幾張表來(lái)取幾個(gè)字段的數(shù)據(jù),返回分頁(yè)排序數(shù)據(jù).
1.在AppConfig注冊(cè)JPAQueryFactory Bean
@Bean
public JPAQueryFactory jpaQueryFactory(EntityManager entityManager) {
return new JPAQueryFactory(new HQLTemplates(), entityManager);
}
2.建一個(gè)DTO(數(shù)據(jù)傳輸對(duì)象)
public class UserDTO {
private String empName;
private String deptName;
private long salary;
//setter,getter略
}
3.查詢例子測(cè)試
private Page<UserDTO> findAll(String empName,Pageable pageable) {
QEmployee qEmp = QEmployee.employee;
QDepartment qDep = QDepartment.department;
List<Predicate> criteria = new ArrayList<>();
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(new Predicate[criteria.size()]));
long total = query.fetchCount();
List<UserDTO> content;
if (pageable == null || total > pageable.getOffset()) {
Map<String, SimpleExpression<?>> map = new HashMap<>();
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();
}
return new PageImpl<>(content, pageable, total);
}
@Test
public void test() {
Pageable pageable = new PageRequest(0, 10, new QSort(new OrderSpecifier<>(Order.DESC, QEmployee.employee.salary), new OrderSpecifier<>(Order.ASC, QDepartment.department.name)));
Page<UserDTO> page = findAll("name", pageable);
for (UserDTO userDTO : page) {
System.out.println("userDTO = " + userDTO);
}
}
參考資料
1:http://docs.spring.io/spring-data/jpa/docs/1.10.x/reference/pdf/spring-data-jpa-reference.pdf
2:https://spring.io/blog/2011/04/26/advanced-spring-data-jpa-specifications-and-querydsl/
以上就是本文的全部?jī)?nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。
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