Hibernate懒惰属性获取配置

Question

I need to lazy load entity properties (image files) with Hibernate.However I do not understand the configuration required for it.

According to https://docs.jboss.org/hibernate/orm/4.3/manual/en-US/html_single/#performance-fetching-lazyproperties I need to setup bytecode instrumentation to lazy load properties.

    <taskdef name="instrument" classname="org.hibernate.tool.instrument.InstrumentTask">
        <classpath path="${jar.path}"/>
        <classpath path="${classes.dir}"/>
        <classpath refxml:id="lib.class.path"/>
    </taskdef>
    <instrument verbose="true">
        <fileset dir="${testclasses.dir}/org/hibernate/auction/model">
            <include name="*.class"/>
        </fileset>
    </instrument>
</target>

I do not understand what path I have to give to "lib.class.path" and "${testclasses.dir}".

Answer 1

You can use annotations to specify what type of fetch do you want for that specific parameter.

@Entity
@Table(name = "USER")
public class UserLazy implements Serializable {

    @Id
    @GeneratedValue
    @Column(name = "USER_ID")
    private Long userId;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "user")
    private Set<OrderDetail> orderDetail = new HashSet();

    // standard setters and getters
    // also override equals and hashcode

}

Here is also some extra explanations: https://howtodoinjava.com/hibernate/lazy-loading-in-hibernate/