spring-data-jpa querydsl使用

1.添加依赖

<dependency>
    <groupId>com.querydsl</groupId>
    <artifactId>querydsl-jpa</artifactId>
</dependency>
<dependency>
    <groupId>com.querydsl</groupId>
    <artifactId>querydsl-apt</artifactId>
    <scope>provided</scope>
</dependency>

2.添加插件，可以自动生成表

<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>

3.创建实体，添加entity注解。

@Entity
public class Person implements Serializable {
    @Id
    private Long id;
    private String name;
    private Integer age;

    public Long getId() {
        return id;
    }

    public void setId(Long 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;
    }
}

4.创建查询接口。

public interface PersonRepository extends QuerydslPredicateExecutor<Person> {
}
5.使用 mvn compile 后自动生成QPerson，生成后可以将类复制到需要的地方。
6.也可以使用

@Autowired
//@PersistenceContext
private EntityManager entityManager;

 @PostConstruct
//    public void init() {
//        queryFactory = new JPAQueryFactory(entityManager);
//    }