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。
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1.pom.xml
4.0.0
org.exam
testjava
1.0.0
${project.artifactId}
UTF-8
UTF-8
1.8
4.2.5.RELEASE
Hopper-SR1
4.1.1
5.1.0.Final
8.0.32
1.1.7
5.1.33
4.12
org.springframework
spring-framework-bom
${spring.version}
import
pom
org.springframework.data
spring-data-releasetrain
${spring-data.version}
import
pom
org.apache.maven.plugins
maven-compiler-plugin
3.1
${java.version}
${java.version}
com.mysema.maven
maven-apt-plugin
1.0.4
generate-sources
process
target/generated-sources
com.querydsl.apt.jpa.JPAAnnotationProcessor
org.springframework.data
spring-data-jpa
org.springframework.data
spring-data-MongoDB
com.querydsl
querydsl-apt
${querydsl.version}
provided
com.querydsl
querydsl-jpa
${querydsl.version}
com.querydsl
querydsl-mongodb
${querydsl.version}
org.hibernate
hibernate-entitymanager
${hibernate.version}
org.apache.tomcat
tomcat-jdbc
${tomcat.version}
org.springframework
spring-test
ch.qos.logback
logback-classic
${logback.version}
mysql
mysql-connector-java
${mysql.version}
junit
junit
${junit.version}
central
Central Repository
http://repo1.maven.org/maven2
default
false
2.Domain类
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类
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,QueryDslPredicateExecutor{
Collection findByIdIn(Collection 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, QueryDslPredicateExecutor {
Collection findByIdIn(Collection ids);
}
JPA有JpaRepository,MongoDB有MongoRepository,它俩都继承PagingAndSortingRepository
3.配置类
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.测试类
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默认为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 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 all = mongoEmployeeRepository.findAll(null, new PageRequest(0, 8));
for (Employee employee : 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
public JPAQueryFactory jpaQueryFactory(EntityManager entityManager) {
return new JPAQueryFactory(new HQLTemplates(), entityManager);
}2.建一个DTO(数据传输对象)
public class UserDTO {
private String empName;
private String deptName;
private long salary;
//setter,getter略
}3.查询例子测试
private Page findAll(String empName,Pageable pageable) {
QEmployee qEmp = QEmployee.employee;
QDepartment qDep = QDepartment.department;
List 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 content;
if (pageable == null || total > pageable.getOffset()) {
Map> 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 page = findAll("name", pageable);
for (UserDTO userDTO : 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，欢迎关注创新互联行业资讯频道。
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