作者：ha遗忘的密 | 来源：互联网 | 2023-09-15 12:22
所谓基本类型，就是指java.lang.String,java.lang.Integer等基本类 以及用户编写的非实体类，虽然map中的数据是我们的数据库中的一个表，但我们不必为他创建P
所谓基本类型，就是指java.lang.String,java.lang.Integer等基本类 以及用户编写的非实体类，虽然map中的数据是我们的数据库中的一个表，但我们不必为他创建POJO类及HBM文件
数据库结构：
create
table
teamMap (id
varchar
(
32
),teamname
varchar
(
32
));
create
table
studentMap (name
varchar
(
32
),description
varchar
(
32
), team_id
varchar
(
32
));
实体类：（只有Team）,其中的student无实体类，用表studentMap的name字段作为key,description作为value
package
Collection.Map.Simple;
import
java.util.HashMap;
import
java.util.Map;
public
class
Team
...
{
private
String id;
private
String teamname;
private
Map students
=
new
HashMap();
public
String getId()
...
{
return
id;
}
public
void
setId(String id)
...
{
this
.id
=
id;
}
public
String getTeamname()
...
{
return
teamname;
}
public
void
setTeamname(String teamname)
...
{
this
.teamname
=
teamname;
}
public
Map getStudents()
...
{
return
students;
}
public
void
setStudents(Map students)
...
{
this
.students
=
students;
}
}
Team.hbm.xml
xml version="1.0" encoding="utf-8"
?>
DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"
>
<
hibernate-mapping
>
<
class
name
="Collection.Map.Simple.Team"
table
="teamMap"
>
<
id
name
="id"
unsaved-value
="null"
>
<
generator
class
="uuid.hex"
>
generator
>
id
>
<
property
name
="teamname"
type
="string"
column
="teamname"
>
property
>
<
map
name
="students"
table
="studentMap"
>
<
key
column
="team_id"
>
key
>
<
index
column
="name"
type
="string"
>
index
>
<
element
type
="string"
column
="description"
>
element
>
map
>
class
>
hibernate-mapping
>
Hibernate.cfg.xml
xml version='1.0' encoding='UTF-8'
?>
DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"
>
<
hibernate-configuration
>
<
session-factory
>
<
property
name
="connection.username"
>
root
property
>
<
property
name
="connection.url"
>
jdbc:mysql://localhost:3306/schoolproject?characterEncoding=gb2312
&
useUnicode=true
property
>
<
property
name
="dialect"
>
org.hibernate.dialect.MySQLDialect
property
>
<
property
name
="myeclipse.connection.profile"
>
mysql
property
>
<
property
name
="connection.password"
>
1234
property
>
<
property
name
="connection.driver_class"
>
com.mysql.jdbc.Driver
property
>
<
property
name
="hibernate.dialect"
>
org.hibernate.dialect.MySQLDialect
property
>
<
property
name
="hibernate.show_sql"
>
true
property
>
<
property
name
="current_session_context_class"
>
thread
property
>
<
property
name
="jdbc.batch_size"
>
15
property
>
<
mapping
resource
="Collection/Map/Simple/Team.hbm.xml"
/>
session-factory
>
hibernate-configuration
>
测试代码：
package
Collection.Map.Simple;
import
java.io.File;
import
java.util.Map;
import
org.hibernate.Session;
import
org.hibernate.SessionFactory;
import
org.hibernate.Transaction;
import
org.hibernate.cfg.Configuration;
public
class
Test
...
{
public
static
void
main(String[] args)
...
{
String filePath
=
System.getProperty(
"
user.dir
"
)
+
File.separator
+
"
src/Collection/Map/Simple
"
+
File.separator
+
"
hibernate.cfg.xml
"
;
File file
=
new
File(filePath);
System.out.println(filePath);
SessionFactory sessionFactory
=
new
Configuration().configure(file).buildSessionFactory();
Session session
=
sessionFactory.openSession();
Transaction t
=
session.beginTransaction();
Team team
=
new
Team();
team.setTeamname(
"
team1
"
);
Map stuMap
=
team.getStudents();
stuMap.put(
"
stu1
"
,
"
stu1 description
"
);
stuMap.put(
"
stu2
"
,
"
stu2 description
"
);
session.save(team);
t.commit();
}
}
运行结果：
Hibernate: insert into teamMap (teamname, id) values (?, ?)
Hibernate: insert into studentMap (team_id, name, description) values (?, ?, ?)
Hibernate: insert into studentMap (team_id, name, description) values (?, ?, ?)
Hibernate集合映射之Map-----element映射基本类型值
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