java – 带JPA JTA的@Stateless webservice:如何提交被管实体的
发布时间:2020-12-14 19:35:27 所属栏目:Java 来源:网络整理
导读:我有以下简单的webservice声明为@Freeless EJB在GlassFish 3.1.2.2上运行,EclipseLink 2.4.1使用JTA DataSource连接到 MySQL数据库: @POST@Consumes(MediaType.APPLICATION_JSON)public Response update(TimeRow e) throws Exception { if ((e.getKey() ==
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我有以下简单的webservice声明为@Freeless EJB在GlassFish 3.1.2.2上运行,EclipseLink 2.4.1使用JTA DataSource连接到
MySQL数据库:
@POST
@Consumes(MediaType.APPLICATION_JSON)
public Response update(TimeRow e) throws Exception {
if ((e.getKey() == null) || !e.getKey().keyValid()) {
return Response.status(400).build();
}
TimeRow existing = em.find(TimeRow.class,e.getKey());
if (existing == null) {
em.persist(e);
} else {
existing.setValues(e.getValues());
em.flush();
}
return Response.status(204).build();
}
TimeRow的实体类: @Entity
@NamedQueries({
@NamedQuery(name="TimeRow.findAllByUser",query="SELECT t FROM TimeRow t WHERE t.table.userId = :uid")
})
public class TimeRow implements Serializable {
@EmbeddedId
private TimeRowPK key;
@MapsId("userId")
@JoinColumn(name = "USERID",referencedColumnName = "userId")
@ManyToOne
private UserTable table;
@Column(name="ROWVALUES")
private List<Double> values;
public TimeRow() {
this.key = new TimeRowPK();
this.values = new ArrayList<Double>(20);
extendValuesTo20();
}
public TimeRow(String uid,Date date) {
this.key = new TimeRowPK(date,uid);
this.table = new UserTable(uid);
this.values = new ArrayList<Double>(20);
extendValuesTo20();
}
public List<Double> getValues() {
return values;
}
public void setValues(List<Double> values) {
this.values = values;
extendValuesTo20();
}
private void extendValuesTo20() {
if (this.values.size() < 20) {
for (int i = this.values.size(); i < 20; i++) {
this.values.add(0.0);
}
}
}
}
@EmbeddableId TimeRowPK: @Embeddable
public class TimeRowPK implements Serializable {
public TimeRowPK() { }
public TimeRowPK(Date date,String userId) {
this.date = date;
this.userId = userId;
}
@Column(name="DAY")
private Date date;
@Column(name = "USERID")
private String userId;
public boolean keyValid() {
return ((date != null) && ((userId != null) && !userId.isEmpty()));
}
}
persistence.xml(没有< persistence>标记): <persistence-unit name="test" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>jdbc/test</jta-data-source>
<class>com.test.TimeRow</class>
<class>com.test.TimeRowPK</class>
<class>...</class>
<properties>
<property name="eclipselink.ddl-generation" value="create-tables" />
<property name="eclipselink.ddl-generation.output-mode" value="database" />
</properties>
</persistence-unit>
Web服务声明: @Path("row")
@Stateless
public class TimeRowWebService {
@PersistenceContext(unitName = "test")
private EntityManager em;
...
}
问题是如果实体存在,则更改仅存储在PersistenceContext中,但它们不会提交到数据库.这意味着我可以使用更改检索正确的数据,但是例如,如果我重新启动AS,则更改将消失. AS日志中没有错误. 所以我想我必须做一些bean级别的手动事务处理来完成这项工作.我究竟需要添加什么才能使其正常工作? 解决方法
在努力使@EmbeddedId方式运行之后,我尝试使用生成的@Id实现它,然后为这两个关键字段添加一个唯一约束.
实体 public class TimeRow implements Serializable {
@Id
@GeneratedValue
private long id;
@JoinColumn(name = "USERID",referencedColumnName = "USERID")
@ManyToOne(optional = false)
private UserTable table;
@Basic(optional = false)
@Column(name = "DAY")
@Temporal(TemporalType.DATE)
private Date date;
@Lob
@Column(name="ROWVALUES")
private List<Double> values;
...
}
另外,我已经将数据库引擎从MyISAM更改为InnoDB以获得更好的外键支持.为此,我在[mysqld]部分下添加了default-storage-engine = innodb到/etc/mysql/my.cnf. 使用DDL生成数据库结构后,对于USERID和DAY,我有added a unique constraint: alter table TIMEROW add unique index(USERID,DAY); 现在它正常工作并且数据被正确修改:)非常感谢所有为此问题做出贡献的人! (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |
