我正在努力与Hibernate,并找不到工作的解决方案来做我想做的。这是一个web服务btw。休眠/ @ElementCollection和@XmlRootElement
简短说明: 我有一个对象(Composant)的列表,它必须嵌入到主对象(Projet)中。我想坚持我的数据库(PostgreSQL)。要做到这一点我将它们设置为:
我的第一台被命名为T_PROJET 它containes标记为PRJ_NAME 列表中的ID,我挣扎在ComponentList 和过期日期PRJ_DATE
而为该表被命名为T_COMPOSANT。 有一个自动生成的ID:COMP_ID。 的名称COMP_NOM 值COMP_MONTANT 和优先COMP_IMPORTANCE
在我的HMI,我可以创造一个谟与至少一个Composant但我可以添加更多(最多5 Composant一个谟),以及Composants会保存为列表。
这里是什么,我往往会产生对我的HMI一个JSON例如:
{
"name":"Example",
"dateLimite":"2018-08-08",
"composant_1": {
"name":"Vol",
"montant": 1200,
"importance":1
},
"composant_2": {
"name":"Truc",
"montant": 1200,
"importance":1
},
"composant_3": {
"name":"Bidule",
"montant": 1200,
"importance":1
},
"composant_4": {
"name":"Machin",
"montant": 1200,
"importance":1
},
"composant_5": {
"name":"Wesh",
"montant": 1200,
"importance":1
}
}
这里的主要对象 “谟”:
@Entity
@Table(name = "T_PROJET")
@XmlRootElement
public class Projet implements Serializable{
private static final long serialVersionUID = 1L;
private String name;
private List<Composant> composants;
private Date dateLimite;
public Projet() {
super();
}
public Projet(String name, List <Composant> composants, Date dateLimite) {
this.name = name;
this.composants = composants;
this.dateLimite = dateLimite;
}
@Id
@Column(name = "PRJ_NOM", nullable = false)
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@ElementCollection
@CollectionTable(name="T_COMPOSANT", joinColumns = @JoinColumn(name = "COMP_ID"))
@Embedded
@Column(name="COMP_ID", nullable = true)
public List<Composant> getComposants() {
return composants;
}
public void setComposants(List <Composant> composants) {
this.composants = composants;
}
@Column(name="PRJ_DATE")
public Date getDateLimite() {
return dateLimite;
}
public void setDateLimite(Date dateLimite) {
this.dateLimite = dateLimite;
}
}
与 “Composant”:
@Embeddable
@Table(name = "T_COMPOSANT")
@XmlRootElement
public class Composant implements Serializable {
private static final long serialVersionUID = 1L;
private int composant_id;
private String name;
private int montant;
private int importance;
public Composant(){
super();
}
public Composant(final int composant_id, final String name, final int montant, final int importance) {
this.composant_id = composant_id;
this.name = name;
this.montant = montant;
this.importance = importance;
}
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "COMP_ID")
public int getComposant_id() {
return composant_id;
}
public void setComposant_id(int composant_id) {
this.composant_id = composant_id;
}
@Column(name = "COMP_NOM",nullable = true)
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Column(name="COMP_MONTANT", nullable = true)
public int getMontant() {
return montant;
}
public void setMontant(int montant) {
this.montant = montant;
}
@Column(name = "COMP_IMPORTANCE", nullable = true)
public int getImportance() {
return importance;
}
public void setImportance(int importance) {
this.importance = importance;
}
}
在每次尝试中,我都会得到一个“在继承状态层次结构中找不到声明类”的错误。 我敢肯定,我错过了关于@ElementCollection和@Embeddable注释的东西,但无法弄清楚究竟在哪里(经过了我的Antonio Goncalves的书,但没有回答,或者我无法正确阅读)。 任何想法,我应该找什么?
感谢您的帮助!
感谢您的回答!它适用于第二种解决方案。 – raik