軟件版本:
hibernate-3.2.0.cr2
hibernate-annotations-3.2.0.CR1
IDE:
idea 5.1
以前都是用XDoclet來實現類似Annotation的功能,但是xdoclet的版本更新實在太慢,永遠跟不上hibernate的更新速度,導致很多hibernate新的功能xdoclet都沒辦法支持.還好,jdk5.0有了Annotation,而且hibernate也開始支持Annotation了.
原來以為從xdoclet轉到Annotation很簡單,沒想到還是遇到了問題,先看代碼:
?1
package?test;
?2
?3import?org.hibernate.annotations.Entity;
?4
?5import?javax.persistence.Id;
?6import?java.io.Serializable;
?7
?8@Entity
?9
public?class?Flight?implements?Serializable
{
10
??Long?id;
11??String?name;
12
13??@Id
14
??public?Long?getId(){
15????return?id;
16
??}
17
18??public?void?setId(Long?id){
19????this.id=id;
20??}
21
22??public?String?getName(){
23????return?name;
24??}
25
26??public?void?setName(String?name){
27????this.name=name;
28??}
29
30??public?boolean?equals(Object?o){
31????if(this==o)?return?true;
32????if(o==null||getClass()!=o.getClass())?return?false;
33
34????final?Flight?flight=(Flight)o;
35
36????if(id!=null?!id.equals(flight.id):flight.id!=null)?return?false;
37????if(name!=null?!name.equals(flight.name):flight.name!=null)?return?false;
38
39????return?true;
40??}
41
42??public?int?hashCode(){
43????int?result;
44????result=(id!=null?id.hashCode():0);
45????result=29*result+(name!=null?name.hashCode():0);
46????return?result;
47??}
48
}
49 看上去沒什么問題吧?沒想到運行的時候根本跑不起來,老是提示:
?????[java]?10:54:55,842??INFO?SessionFactoryObjectFactory:82?-?Not?binding?factory?to?JNDI,?no?JNDI?name?configured
?????[java]?org.hibernate.hql.ast.QuerySyntaxException:?Flight?is?not?mapped?[from?Flight]
?????[java]?????at?org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:180)
?????[java]?????at?org.apache.tools.ant.taskdefs.Java.run(Java.java:710)
?????[java]?????at?org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:178)
?????[java]?????at?org.apache.tools.ant.taskdefs.Java.execute(Java.java:84)
?????[java]?????at?org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
?????[java]?????at?org.apache.tools.ant.Task.perform(Task.java:364)
?????[java]?????at?org.apache.tools.ant.Target.execute(Target.java:341)
?????[java]?????at?org.apache.tools.ant.Target.performTasks(Target.java:369)
?????[java]?????at?org.apache.tools.ant.Project.executeSortedTargets(Project.java:1216)
?????[java]?????at?org.apache.tools.ant.Project.executeTarget(Project.java:1185)
?????[java]?????at?org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:40)
?????[java]?????at?org.apache.tools.ant.Project.executeTargets(Project.java:1068)
?????[java]?????at?org.apache.tools.ant.Main.runBuild(Main.java:668)
?????[java]?????at?org.apache.tools.ant.Main.startAnt(Main.java:187)
?????[java]?????at?org.apache.tools.ant.launch.Launcher.run(Launcher.java:246)
?????[java]?????at?org.apache.tools.ant.launch.Launcher.main(Launcher.java:67) 看了半天看不出有什么問題,最后終于參考hibernate-annotations-3.2.0.CR1里面單元測試的代碼才發現是這段代碼有問題:
1import?org.hibernate.annotations.Entity;
2
3import?javax.persistence.Id;
4import?java.io.Serializable;
5 要改成:
1import?javax.persistence.Id;
2import?javax.persistence.Entity;
3import?java.io.Serializable; 原來我用idea開發時,在自動完成的時候想當然地選用了org.hibernate.annotations包下面的annotation,而實際上應該使用javax.persistence包下面的annotation.想想看也很有道理:這樣一來我們的JAVA bean就不用import hibernate的包了,用的都是標準的java包.