Question

我有以下实体

import static javax.persistence.GenerationType.IDENTITY;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;

import org.hibernate.annotations.Type;

@Entity
@Table(name = "Privilege", uniqueConstraints = @UniqueConstraint(columnNames = "name"))
public class Privilege implements java.io.Serializable {
private static final long serialVersionUID = 8357379972506504809L;

private Long privilegeId;
private String name;
private String description;

public Privilege() {
}

@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "privilegeID", unique = true, nullable = false)
public Long getId() {
    return this.privilegeId;
}

public void setId(Long privilegeId) {
    this.privilegeId = privilegeId;
}


@Column(name = "name", unique = true, length = 45)
public String getName() {
    return this.name;
}

public void setName(String name) {
    this.name = name;
}


@Column(name = "description", length = 65535)
@Type(type="text")
public String getDescription() {
    return this.description;
}

public void setDescription(String description) {
    this.description = description;
}

}

映射MySQL DB中的表。我正在尝试通过以下QueryDSL代码检索数据

public Privilege findByName(final String name) throws EntityNotFoundException {
        Privilege workgroupPrivilege = new JPAQuery(getEntityManager())
                .from(privilege)
                .where(privilege.name.eq(name))
                .uniqueResult(privilege);
        if (workgroupPrivilege == null)
            throw new EntityNotFoundException("Cannot find entity "
                    + Privilege.class.getCanonicalName()
                    + " with name <" + name + ">");
        else
            return workgroupPrivilege;
    }

问题是findByName()代码返回了Privilege Entity对象的实例，但其字段中的数据为null。这意味着Entity-DB Table绑定已正确完成（其他我将拥有一个null Privilege Entity实例）。

编辑：

网络应用将此字段添加到空白的权限实例

handler = org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer@48f52e0b

这个增加的字段可能是解决问题的关键吗？

你可能遇到什么问题？

Answer 1

由于延迟数据加载，调试器向我显示没有数据。

从MySQL DB检索数据后的空实体

1 个答案: