我有上面的表我需要用注释编写HIbernate实体类 和映射
我在获取ObjectAttributes列表时遇到问题..
类编写如下
@Entity
public class Object {
@Id
private int id;
private String name;
@OneToMany(mappedBy="object",fetch=FetchType.LAZY)
private List<ObjectAttribute> attrubuteList;
}
@Entity
public class ObjectAttribute {
@Id
private int id;
@ManyToOne
@JoinColumn(name="objectId")
private Object object;
private String name;
}
@Entity
public class Filter {
@Id
private int filterId;
@ManyToOne
@JoinColumn(name="ObjectId")
private Object object;
private String filterName;
@OneToMany(mappedBy="filter")
private Set<FilterAttribute> filterValues;
}
@Entity
public class FilterAttribute implements Serializable {
@Id
private int filterAttrId;
@Id
@ManyToOne
@JoinColumn(name="objectId")
private Object object;
@Id
@ManyToOne
@JoinColumn(name="filterId")
private Filter filter;
@Id
@ManyToOne
@JoinColumn(name="attributeId")
private ObjectAttribute attribute;
private String value;
}
注意没有添加getter和setter
并测试代码如下
List<Object> list = sess.createCriteria(Object.class).list();
for(Object ob: list)
{
System.out.println("Object name : "+ ob.getName());
List<ObjectAttribute> attList = ob.getAttrubuteList();
for (Iterator iterator = attList.iterator(); iterator.hasNext();) {
ObjectAttribute objectAttribute = (ObjectAttribute) iterator
.next();
System.out.println(objectAttribute.getName());
}
}
attList = ob.getAttrubuteList();返回null
答案 0 :(得分:0)
在我的测试代码中创建Object,如下所示
Object obj = new Object();
obj.setId(1);
obj.setName("Employee");
sess.save(obj);
ObjectAttribute ageAtt = new ObjectAttribute();
ageAtt.setId(1);
ageAtt.setName("age");
ageAtt.setObject(obj);
sess.save(ageAtt);
ObjectAttribute depAtt = new ObjectAttribute();
depAtt.setId(2);
depAtt.setName("department");
depAtt.setObject(obj);
sess.save(depAtt);
ObjectAttribute attName = new ObjectAttribute();
attName.setId(3);
attName.setName("name");
attName.setObject(obj);
sess.save(attName);
我没有添加这些行
obj.getAttrubuteList().add(depAtt);
obj.getAttrubuteList().add(attName);
obj.getAttrubuteList().add(ageAtt);
但我不知道为什么我们需要这样做!!