JSON映射异常:没有为类找到序列化程序

时间:2012-01-23 10:29:17

标签: json hibernate spring-mvc jackson

我正在使用spring MVC和restful web services(JACKSON)。我有一个名为p_project的表,它有3列。 id,region_id,name。 region_id引用区域表。我的实体如代码所示。

@Entity
@XmlRootElement(name="project")
@Table(name = "P_PROJECT")
@NamedQueries( {

    @NamedQuery(name = "Project.findAll", 
                query = "select p from Project p order by lower(p.name)", 
                hints = { 
                         @QueryHint(name = "org.hibernate.cacheable", value = "true") 
                        }
                ) 
})
public class Project extends AbstractSimpleNameEntity<Integer> implements Serializable
{

private Region region;

private String name;

public Project()
{
    super();
}

public Project(Integer id)
{
    super(id);
}

public Project(String name)
{
    super(name);
}

@Id
@Column(name = "ID")
@GeneratedValue(generator = "P_PROJECT_SEQ", strategy = GenerationType.SEQUENCE)
@SequenceGenerator(name = "P_PROJECT_SEQ", sequenceName = "P_PROJECT_SEQ",    allocationSize = 1)
public Integer getId()
{
    return id;
}


            @ManyToOne(fetch = FetchType.LAZY)
            @JoinColumn(name = "REGION_ID")
            public Region getRegion() {
                            return region;
            }

            public void setRegion(Region region) {
                            this.region = region;
            }

@Column(name = "NAME")
public String getName()
{
    return name;
}
}

在获取所有项目时,我收到以下错误。有人可以帮忙吗?

org.codehaus.jackson.map.JsonMappingException: No serializer found for class       
org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer and no properties   
discovered to create BeanSerializer (to avoid exception, disable 
SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: 
java.util.ArrayList[0]->com.sony.prince.entity.Project["region"]->
    com.sony.prince.entity.Region_$$_javassist_2["hibernateLazyInitializer"])

0 个答案:

没有答案