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 PagefindAll(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。