之前研究Jooq，今天来研究一下搭配JPA的QueryDSL吧。

简介

Querydsl 是一个Java开源框架用于构建类型安全的SQL查询语句。它采用API代替拼凑字符串来构造查询语句。可跟 Hibernate 和 JPA 等框架结合使用。

新建Spring Boot项目

。。。还说啥？

1. pom.xml

<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <!--QueryDSL支持--> <dependency> <groupId>com.querydsl</groupId> <artifactId>querydsl-apt</artifactId> <scope>provided</scope> </dependency> <!--QueryDSL支持--> <dependency> <groupId>com.querydsl</groupId> <artifactId>querydsl-jpa</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> <!-- 这个插件是为了让程序自动生成query type(查询实体，命名方式为："Q"+对应实体名) --> <plugin> <groupId>com.mysema.maven</groupId> <artifactId>apt-maven-plugin</artifactId> <version>1.1.3</version> <executions> <execution> <goals> <goal>process</goal> </goals> <configuration> <outputDirectory>target/generated-sources/java</outputDirectory> <processor>com.querydsl.apt.jpa.JPAAnnotationProcessor</processor> </configuration> </execution> </executions> </plugin> </plugins> </build>

2. application.yml

server: port: 8888spring: datasource: url: jdbc:mysql://IP地址:3306/querydsl?characterEncoding=UTF-8 username: 用户名 password: 密码 jpa: show-sql: true # 控制台打印SQL hibernate: ddl-auto: update

3. JPAQueryFactory Bean

/** * JPAQueryFactory Bean * @author zhouzhaodong */@Configurationpublic class PeopleQueryConfig { @Bean public JPAQueryFactory jpaQuery(EntityManager entityManager) { return new JPAQueryFactory(entityManager); }}

4. 新建实体类

/** * 实体类 * @author zhouzhaodong */@Entity@Table(name="people")public class People { @Id @Column(name="id") @GeneratedValue private Integer id; @Column(name="name") private String name; @Column(name="age") private Integer age; @Column(name="address") private String address; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; }}

5. 新建service

/** * service * @author zhouzhaodong */public interface PeopleService { /** * 根据id查询 * @param id * @return */ People selectOne(Integer id); }

6. 新建serviceImpl

/** * serviceImpl * @author zhouzhaodong */@Servicepublic class PeopleServiceImpl implements PeopleService { @Resource JPAQueryFactory queryFactory; @Override public People selectOne(Integer id) { QPeople people = QPeople.people; return queryFactory.selectFrom(people).where(people.id.eq(id)).fetchOne(); }}

7. 新建controller

/** * controller * @author zhouzhaodong */@RestControllerpublic class PeopleController { @Resource PeopleService peopleService; @RequestMapping("/selectById") public People selectById(){ return peopleService.selectOne(0); } }

8. 新建repository，可以使用JPA原有的功能

/** * 实现jpaRepository * @author zhouzhaodong */public interface PeopleRepository extends JpaRepository<People, Integer> {}

9. postman测试

数据库数据如下：

请求结果：

Github代码地址：https://github.com/zhouzhaodong/springboot/tree/master/querydsl

到此这篇关于Spring Boot整合QueryDSL的实现示例的文章就介绍到这了,更多相关SpringBoot整合QueryDSL内容请搜索以前的文章或继续浏览下面的相关文章希望大家以后多多支持！