當(dāng)EJB3.0加hibernate和標(biāo)記語(yǔ)言后,哇哦,用起來(lái)太爽了夜,和在學(xué)校學(xué)的EJB2.1完全不一樣了哦,不說(shuō)看看代碼就知道了

先寫(xiě)一個(gè)接口LOOK什么都不用繼承的

然后看看實(shí)體類(lèi)的寫(xiě)法一個(gè)字酷

@SuppressWarnings("serial")
@Entity
@Table(name="DictionaryCatalog")
public class DictionaryCatalogEntity implements Serializable {
 private Integer catalogId;
 private String catalogName;
 private String cataMemo;
 private DictionaryTypeEntity dte;
 private Set<DirectoryData> dce;
 
 @ManyToOne(cascade=CascadeType.ALL ,fetch=FetchType.LAZY,optional=false)
 @JoinColumn(name="id")
 public DictionaryTypeEntity getDte() {
  return dte;
 }
 public void setDte(DictionaryTypeEntity dte) {
  this.dte = dte;
 }
 @OneToMany(cascade=CascadeType.ALL ,fetch=FetchType.LAZY,mappedBy="dataId")
 @OrderBy(value="dataId desc")
 public Set<DirectoryData> getDce() {
  return dce;
 }
 
 public void setDce(Set<DirectoryData> dce) {
  this.dce = dce;
 }
 @Id
 @GeneratedValue
 public Integer getCatalogId() {
  return catalogId;
 }
 public void setCatalogId(Integer catalogId) {
  this.catalogId = catalogId;
 }
 
 @Column(name="catalogName" , nullable=true ,length=50)
 public String getCatalogName() {
  return catalogName;
 }
 public void setCatalogName(String catalogName) {
  this.catalogName = catalogName;
 }
 @Column(name="cataMemo" ,nullable=true ,length=50)
 public String getCataMemo() {
  return cataMemo;
 }
 public void setCataMemo(String cataMemo) {
  this.cataMemo = cataMemo;
 }

}

呵呵連數(shù)據(jù)庫(kù)都自己生成了,你門(mén)說(shuō)酷不

完了是會(huì)話(huà)BEAN

@Stateless
@Remote ({QueryDAO.class})
public class QueryDAOBean implements QueryDAO {
    @PersistenceContext
    protected EntityManager em;

    public void initdate() {
            Query query = em.createQuery("select count(p) from Person p");
            Object result = query.getSingleResult();
            if (result == null || Integer.parseInt(result.toString()) == {          

}
查詢(xún)基本是上是寫(xiě)完了,看是不是很類(lèi)似HIBERNATE的查詢(xún)語(yǔ)言呵呵,但是EJB又封裝了哈，現(xiàn)在EJB終于可以和SPRING想抗衡了哦,呵呵)

(此例子3個(gè)類(lèi)沒(méi)有任何關(guān)系,所以大家看看如何寫(xiě)就好咯,呵呵.后面我會(huì)寫(xiě)個(gè)例子讓大家參考的)