This article will introduce the elements of the Hibernate Persistence class (map) set attribute in Java as component ing. I hope this tutorial will help you.
1. hibernate. cfg. xml
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<! DOCTYPE hibernate-configuration PUBLIC
"-// Hibernate/Hibernate Configuration DTD 3.0 // EN"
Http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd> <Hibernate-configuration>
<Session-factory>
<! -- Configure database Dialect -->
<Property name = "hibernate. dialect"> org. hibernate. dialect. MySQLDialect </property>
<! -- Configure the database driver -->
<Property name = "hibernate. connection. driver_class"> com. mysql. jdbc. Driver </property>
<! -- Configure the database username -->
<Property name = "hibernate. connection. username"> root </property>
<! -- Configure the Database Password -->
<Property name = "hibernate. connection. password"> root </property>
<! -- Configure the database url -->
<Property name = "hibernate. connection. url"> jdbc: mysql: // localhost: 3306/hibernate </property>
<! -- Configure the maximum capacity of the data pool -->
<Property name = "hibernate. c3p0. max_size"> 20 </property>
<! -- Configure the minimum capacity of the data pool -->
<Property name = "hibernate. c3p0. min_size"> 1 </property>
<! -- Configure the timeout threshold for data links -->
<Property name = "hibernate. c3p0. timeout"> 5000 </property>
<! -- Display whether the executed SQL is printed in the background on the console -->
<Property name = "hibernate. show_ SQL"> true </property>
<! -- Whether to display printed SQL statements in a friendly format -->
<Property name = "hibernate. format_ SQL"> true </property>
<! -- Print some auxiliary comments -->
<Property name = "hibernate. use_ SQL _comments"> true </property> <Property name = "hibernate. c3p0. max_statements"> 100 </property>
<Property name = "hibernate. c3p0. idle_test_period"> 3000 </property>
<Property name = "hibernate. c3p0. acquire_increment"> 2 </property>
<Property name = "hibernate. c3p0. validate"> true </property>
<! -- Configure the data operation method -->
<Property name = "hbm2ddl. auto"> create </property>
<! -- Add the above Member ing file -->
<Mapping resource = "org/Rudiment/hibernate/Member. hbm. xml"/>
</Session-factory>
</Hibernate-configuration> |
2. Persistence class Member. java
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Package org. Rudiment. hibernate; Import java. util. HashMap;
Import java. util. Map; Public class Member {
Private Integer id;
Private String name;
Private Integer age;
Private Map <String, Address> addresses = new HashMap <String, Address> ();
Public Map <String, Address> getAddresses (){
Return addresses;
}
Public void setAddresses (Map <String, Address> addresses ){
This. addresses = addresses;
}
Public Integer getId (){
Return id;
}
Public void setId (Integer id ){
This. id = id;
}
Public String getName (){
Return name;
}
Public void setName (String name ){
This. name = name;
}
Public Integer getAge (){
Return age;
}
Public void setAge (Integer age ){
This. age = age;
}
} |
3. component class of persistence class
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Package org. Rudiment. hibernate; Import java. util. HashMap;
Import java. util. Map; Public class Address { Private String street;
Private String zipCode;
Private String city; Private Member owner;
Public Member getOwner (){
Return owner;
}
Public void setOwner (Member owner ){
This. owner = owner;
}
Public String getStreet (){
Return street;
}
Public void setStreet (String street ){
This. street = street;
}
Public String getZipCode (){
Return zipCode;
}
Public void setZipCode (String zipCode ){
This.zip Code = zipCode;
}
Public String getCity (){
Return city;
}
Public void setCity (String city ){
This. city = city;
}
} |
4. Persistence class ing File
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<? Xml version = "1.0"?>
<! DOCTYPE hibernate-mapping PUBLIC "-// Hibernate/Hibernate Mapping DTD 3.0 // EN"
Http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd>
<! -- Generated 2013-9-9 19:50:34 by Hibernate Tools 3.4.0.CR1 -->
<Hibernate-mapping package = "org. Rudiment. hibernate">
<Class name = "Member" table = "TEST_MEMBER">
<Id name = "id" column = "ID">
<Generator class = "native"> </generator>
</Id>
<Property name = "age" column = "AGE"> </property>
<Property name = "name" column = "NAME"> </property>
<Map name = "addresses" table = "test_component">
<Key column = "component_id" not-null = "true"/>
<Map-key column = "component_key" type = "string"/>
<Composite-element class = "Address">
<Parent name = "owner"/>
<Property name = "street" column = "home_street"> </property>
<Property name = "zipCode" column = "home_zip_code"> </property>
<Property name = "city" column = "home_city"> </property>
</Composite-element>
</Map>
</Class>
</Hibernate-mapping> |
5. MemberHandler. java
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Package org. Rudiment. hibernate; Import java. util. HashMap;
Import java. util. Map; Import org. hibernate. Session;
Import org. hibernate. SessionFactory;
Import org. hibernate. cfg. Configuration;
Import org. hibernate. service. ServiceRegistry;
Import org. hibernate. service. ServiceRegistryBuilder; Public class MemberHandler { Public static void insert (){
Configuration conf = new Configuration ();
Conf. configure ();
ServiceRegistry sr = new ServiceRegistryBuilder (). applySettings (conf. getProperties (). buildServiceRegistry ();
SessionFactory sf = conf. buildSessionFactory (sr );
Session session = sf. openSession ();
Session. beginTransaction ();
Member m = new Member ();
M. setAge (24 );
M. setName ("Louis ");
Address ad1 = new Address ();
Ad1.setCity ("Guangzhou ");
Ad1.setOwner (m );
Ad1.setStreet ("No. 1 street ");
Ad1.setZipCode ("123 "); Address ad2 = new Address ();
Ad2.setCity ("Shenzhen ");
Ad2.setOwner (m );
Ad2.setStreet ("street 2 ");
Ad2.setZipCode ("456 "); Map <String, Address> am = new HashMap <String, Address> ();
Am. put ("address 1", ad1 );
Am. put ("address 2", ad2 ); M. setAddresses (am );
Session. save (m );
Session. getTransaction (). commit ();
Session. close ();
}
Public static void main (String [] args ){
Insert ();
} } |
Note:
When running MemberHandler, you will find that the backend database has an additional data table test_member and test_component. The table content is as follows:
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Mysql> show tables;
+ --------------------- +
| Tables_in_hibernate |
+ --------------------- +
| Test_component |
| Test_member |
+ --------------------- +
2 rows in set (0.00 sec) Mysql> select * from test_member;
+ ---- + ------ + ------- +
| ID | AGE | NAME |
+ ---- + ------ + ------- +
| 1 | 24 | Louis |
+ ---- + ------ + ------- +
1 row in set (0.00 sec) Mysql> select * from test_component;
+ -------------- + ------------- + --------------- + ----------- + --------------- +
| Component_id | home_street | home_zip_code | home_city | component_key |
+ -------------- + ------------- + --------------- + ----------- + --------------- +
| 1 | 1st Street | 123 | Guangzhou | Address 1 |
| 1 | St. 2nd | 456 | Shenzhen | Address 2 |
+ -------------- + ------------- + --------------- + ----------- + --------------- +
2 rows in set (0.00 sec) |
