One-to-one association of enitybean

I. Engineering architecture:

Engineering Resources: http://download.csdn.net/detail/u012750578/7660633

Ii. Beans. xml configuration

<? XML version = "1.0" encoding = "UTF-8"?> <! -- Annotation-based http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring/ehcache-spring-1.1.xsd http://www.springframework.org/schema/beans --> <beans xmlns = "http://www.w3.org/2001/XMLSchema-instance" xmlns: xsi = "http://www.springframework.org/schema/context" xmlns: context = "http://www.springframework.org" xmlns: AOP =/ Schema/AOP "xmlns: Tx =" http://www.springframework.org/schema/tx "xsi: schemalocation =" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-ao P-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring/ehcache-spring-1.1.xsd "> <context: annotation-config/> <context: component-scan base-package =" com. entity "> </Context: component-scan> <bean id =" da Tasource "class =" org. apache. commons. DBCP. basicdatasource "Destroy-method =" close "> <property name =" driverclassname "value =" oracle. JDBC. driver. oracledriver "/> <property name =" url "value =" JDBC: oracle: thin: @ localhost: 1521: orcl11g "/> <property name =" username "value =" entity "/> <property name =" password "value =" entity "/> <! -- Initial value when the connection pool starts --> <property name = "initialsize" value = "1"/> <! -- Maximum value of the connection pool --> <property name = "maxactive" value = "500"/> <! -- Maximum idle value. after a peak time, the connection pool can slowly release a portion of connections that are no longer in use, until maxidle --> <property name = "maxidle" value = "2"/> <! -- Minimum idle value. when the number of idle connections is less than the threshold value, the connection pool will pre-apply for some connections, so that you do not have time to apply when the peak traffic arrives --> <property name = "minidle" value = "1"/> </bean> <! -- Org. springframework. orm. hibernate3.annotation. annotationsessionfactorybean annotation-based sessionfactroy --> <bean id = "sessionfactory" class = "org. springframework. orm. hibernate3.annotation. annotationsessionfactorybean "name =" sessionfactory "> <property name =" datasource "ref =" datasource "/> <property name =" hibernateproperties "> <value> hibernate. dialect = org. hibernate. dialect. oracledialecthib.pdf. hbm2ddl. auto = UPDA Tehibernate. show_ SQL = truehibernate. format_ SQL = truehibernate. cache. use_second_level_cache = truehibernate. cache. use_query_cache = falsehibernate. cache. provider_class = org. hibernate. cache. ehcacheprovider </value> </property> <! -- Annotatedclasses --> <property name = "annotatedclasses"> <list> <value> COM. entity. one2one. bean. customer </value> <value> COM. entity. one2one. bean. referee </value> <value> COM. entity. one2one. bean. customerprimary </value> <value> COM. entity. one2one. bean. refereeprimary </value> </List> </property> </bean> <bean id = "txmanager" class = "org. springframework. orm. hibernate3.hibernatetransactionmanager "> <property name =" sessionfactory "ref =" sessionfactory "/> </bean> <TX: annotation-driven transaction-Manager =" txmanager "/> </beans>

3. One-to-many relationship based on shared primary keys

1. entitybean

Refereeprimary:

@ Entity @ table (name = "t_primary_referee") public class refereeprimary {private int ID; private string name; private customerprimary customer; @ onetoone @ primarykeyjoincolumnpublic customerprimary getcustomer () {return customer ;} public void setcustomer (customerprimary customer) {This. customer = Customer;} // when using a one-to-one ing based on the primary key, you must change the primary key generation policy to foreign // The customer @ ID @ generatedvalue (generator = "pkgenerator") corresponding to the property ") @ genericgenerator (name = "pkgenerator", strategy = "foreign", [email protected] (Name = "property", value = "customer") Public int GETID () {return ID;} public void setid (int id) {This. id = ID;} Public String getname () {return name;} public void setname (string name) {This. name = Name ;}}

Customerprimary:

@ Entity @ table (name = "t_primary_customer") public class customerprimary {private int ID; private string name; private refereeprimary referee; @ ID // indicates that this ID attribute is a foreign key, and dependent on the ID attribute value (primary key value) of the object bean corresponding to the customer attribute @ genericgenerator (name = "genericgenerator", strategy = "sequence ", parameters = {@ parameter (value = "seq_primary_customer", name = "sequence")}) @ generatedvalue (generator = "genericgenerator") Public int GETID () {return ID ;} /*** Note: Because the ID auto-increment type of the t_referee table has been removed and the class depends on the ID field value of the t_customers table *, the referee object cannot be directly persisted, while the customer object is persisted, the container automatically persists the referee ** @ Param ID */Public void setid (int id) {This. id = ID;} Public String getname () {return name;} public void setname (string name) {This. name = Name;} // Shared primary key @ onetoone (cascade = cascadetype. all) @ primarykeyjoincolumnpublic refereeprimary getreferee () {return referee;} public void setreferee (refereeprimary referee) {This. referee = referee ;}}

2. Service

@ Service ("customerprimaryservice") @ transactionalpublic class customerprimaryservice {@ resourceprivate sessionfactory; // test and save public void saveprimary () {customerprimary customer = new customerprimary (); customer. setname ("Microsoft"); refereeprimary referee = new refereeprimary (); referee. setname ("Zhao Jun"); // join // use a primary key-based one-time pair: only foreign key providers can save the associated customer. setreferee (referee); referee. setcustomer (customer); // first save the non-foreign key side, and first save the primary key side sessionfactory. getcurrentsession (). persist (customer); // store the foreign key again, because the foreign key must reference the primary key value sessionfactory without the foreign key. getcurrentsession (). persist (referee);} // obtain public mermerprimary getcustomerprimary (int id) {return (customerprimary) sessionfactory Based on the ID. getcurrentsession (). get (customerprimary. class, 1);} // obtain public refereeprimary getrefereeprimary (int id) {return (refereeprimary) sessionfactory Based on the ID. getcurrentsession (). get (refereeprimary. class, 1) ;}// remove an association // when a primary key-based pair is used, neither party can remove the association public void removerelationprimary () {customerprimary customer = (customerprimary) sessionfactory. getcurrentsession (). get (customerprimary. class, 1); customer. setreferee (null); sessionfactory. getcurrentsession (). persist (customer);} // remove an association // when a primary key-based pair is used, neither party can remove the association public void removerelationnoprimary () {refereeprimary referee = (refereeprimary) sessionfactory. getcurrentsession (). get (refereeprimary. class, 1); referee. setcustomer (null); sessionfactory. getcurrentsession (). persist (referee);} // because refereeprimary is a non-foreign key statement and cannot maintain the association, if there is an associated customer When deleting refereeprimary, an exception will be thrown // because the customerprimary ID has the idpublic void deletenoforeign () {sessionfactory that references refereeprimary. getcurrentsession (). delete (sessionfactory. getcurrentsession (). get (refereeprimary. class, 1);} // Delete the customerprimary and refereeprimary record public void deleteforeign () {sessionfactory. getcurrentsession (). delete (sessionfactory. getcurrentsession (). get (customerprimary. class, 1);} // test the deletion of Public void deleteall () {// Delete sessionfactory with a foreign key first. getcurrentsession (). delete (sessionfactory. getcurrentsession (). get (customerprimary. class, 2);} // obtain the test list information @ suppresswarnings ("unchecked") public list <customerprimary> getcustomerprimarys () {return sessionfactory. getcurrentsession (). createquery ("from mermerprimary "). list ();} // obtain the list information by testing @ suppresswarnings ("unchecked") public list <refereeprimary> getrefereeprimarys () {return sessionfactory. getcurrentsession (). createquery ("from refereeprimary "). list ();}}

3. JUnit Testing

Public class customerprimaryservicetest {Private Static customerprimaryservice; @ beforeclasspublic static void setupbeforeclass () throws exception {try {applicationcontext = new classpathxmlapplicationcontext ("beans. XML "); customerprimaryservice = (customerprimaryservice) applicationcontext. getbean ("customerprimaryservice");} catch (runtimeexception e) {e. printstacktrace () ;}}// test and save @ testpublic void testsaveprimary () {customerprimaryservice. saveprimary ();} // obtain the association value through the test @ test public void testgetprimarycustomer () {customerprimary customer = customerprimaryservice. getcustomerprimary (1); system. out. println (customer. getreferee (). getname ();} // obtain the association value for the test @ test public void testgetprimaryreferee () {refereeprimary referee = customerprimaryservice. getrefereeprimary (1); system. out. println (referee. getcustomer (). getname ();} // test the removal link @ testpublic void testremoverelationprimary () {customerprimaryservice. removerelationprimary ();} // test the removal link @ testpublic void testremoverelationnoprimary () {customerprimaryservice. removerelationnoprimary ();} // No foreign key. You cannot delete @ testpublic void testdeletenoforeign () {customerprimaryservice. deletenoforeign ();} // a foreign key can be deleted. Deleting is to delete the information of two tables @ testpublic void testdeleteforeign () {customerprimaryservice. deleteforeign ();} // obtain the list information by testing @ testpublic void testgetcustomerprimarys () {for (customerprimary C: customerprimaryservice. getcustomerprimarys () {system. out. println (C. getname () ;}}// obtain the list information for the test @ testpublic void testgetprimaryreferees () {for (refereeprimary R: customerprimaryservice. getrefereeprimarys () {system. out. println (R. getname ());}}}

4. One-to-one association based on foreign keys)
1. entitybean

@ Entity @ table (name = "t_customer") Public Class Customer {private int ID; private string name; private referee; @ ID @ genericgenerator (name = "genericgenerator ", strategy = "sequence", parameters = {@ parameter (value = "seq_t_customer", name = "sequence")}) @ generatedvalue (generator = "genericgenerator") Public int GETID () {return ID;} public void setid (int id) {This. id = ID;} Public String getname () {return name;} public void setname (string name) {This. name = Name;}/*** default foreign key name referee_id * @ onetoone * Public referee getreferee () {return referee ;} * @ return * // ***/use the new foreign key name: referee1_id * @ onetoone @ joincolumn (name = "referee1_id") Public referee getreferee () {return referee ;} * @ return */@ onetoone @ joincolumn (name = "referee_id") Public referee getreferee () {return referee;}/*** as shown in the code above, the getreferee method uses @ onetoone to set * when the customer object is loaded, the referee object will be loaded at the same time, the default foreign key field is the referee attribute name + "_" + id * in the customer class, that is, referee_id * @ Param referee */Public void setreferee (referee) {This. referee = referee ;}}

REFEREE:

@Entity@Table(name="t_referee")public class Referee {private int id;private String name;private Customer customer;@Id@GenericGenerator(name = "GenericGenerator", strategy = "sequence",parameters = { @Parameter(value = "seq_t_referee", name = "sequence") })@GeneratedValue(generator="GenericGenerator")public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}@OneToOne(mappedBy="referee")public Customer getCustomer() {return customer;}public void setCustomer(Customer customer) {this.customer = customer;}}

2. Service

@ Service ("customerservice") @ transactionalpublic class customerservice {@ resourceprivate sessionfactory; Public void saveforgin () {customer = new customer (); customer. setname ("Microsoft"); referee = new referee (); referee. setname ("Zhao Jun"); customer. setreferee (referee); referee. setcustomer (customer); // save sessionfactory without foreign keys first. getcurrentsession (). persist (referee); sessionfactory. getcurrentsession (). persist (customer);} public customer getcustomer (int id) {return (customer) sessionfactory. getcurrentsession (). get (customer. class, ID);} public referee getreferee (int id) {return (referee) sessionfactory. getcurrentsession (). get (referee. class, ID);}/*** foreign key can maintain the link to remove the link */Public void removerelationforeign () {customer = (customer) sessionfactory. getcurrentsession (). get (customer. class, 1); customer. setreferee (null); sessionfactory. getcurrentsession (). persist (customer);}/*** the relationship cannot be maintained because there is no foreign key. Therefore, when deleting a referee, if there is an associated customer, an exception will be thrown, causing both parties to fail to delete */Public void removerelationnoforeign () {sessionfactory. getcurrentsession (). delete (sessionfactory. getcurrentsession (). get (referee. class, 1);}/*** foreign key can maintain the relationship, * removes the association first * deletes the foreign key, */Public void removerelationforeignone () {sessionfactory. getcurrentsession (). delete (sessionfactory. getcurrentsession (). get (customer. class, 1);} public void deletenoforeignone () {// Delete sessionfactory with a foreign key first. getcurrentsession (). delete (sessionfactory. getcurrentsession (). get (referee. class, 1);} public void deleteforeignone () {// Delete sessionfactory with a foreign key first. getcurrentsession (). delete (sessionfactory. getcurrentsession (). get (customer. class, 1);} public void deleteforeigntow () {// Delete sessionfactory with a foreign key first. getcurrentsession (). delete (sessionfactory. getcurrentsession (). get (customer. class, 1); // Delete sessionfactory without foreign keys. getcurrentsession (). delete (sessionfactory. getcurrentsession (). get (referee. class, 1) ;}@ suppresswarnings ("unchecked") public list <customer> getmers MERs () {return sessionfactory. getcurrentsession (). createquery ("from customer "). list () ;}@ suppresswarnings ("unchecked") public list <referee> getreferees () {return sessionfactory. getcurrentsession (). createquery ("from referee "). list ();}}

3. JUnit Testing

Public class customerservicetest {Private Static customerservice; @ beforeclasspublic static void setupbeforeclass () throws exception {try {applicationcontext = new classpathxmlapplicationcontext ("beans. XML "); customerservice = (customerservice) applicationcontext. getbean ("customerservice");} catch (runtimeexception e) {e. printstacktrace () ;}}// test and save @ testpublic void testsaveforgin () {customerservice. saveforgin ();} // test to obtain the attribute value of the associated object @ testpublic void testgetcustomer () {customer = customerservice. getcustomer (1); system. out. println (customer. getreferee (). getname ();} // test to obtain the attribute value of the associated object @ testpublic void testgetreferee () {referee = customerservice. getreferee (1); system. out. println (referee. getcustomer (). getname ();} // test the removal of a link. // The foreign key can maintain the link and remove the link @ testpublic void testremoverelationforeign () {customerservice. removerelationforeign ();} // test the function of removing a link from a link. // No foreign key exists. The link cannot be maintained. Therefore, if a referee is deleted, an exception will be thrown, causing both parties to fail to delete @ testpublic void testremoverelationnoforeign () {customerservice. removerelationnoforeign ();} // You cannot delete @ testpublic void testdeletenoforeignone () {customerservice. deletenoforeignone ();} // deletes a foreign key. You can delete @ testpublic void testdeleeteforeignone () {customerservice. deleteforeignone () ;}// Delete the foreign key first, and then delete the non-foreign key @ testpublic void testdeleteforeigntow () {customerservice. deleteforeigntow ();} @ testpublic void testgetreferees () {for (referee R: customerservice. getreferees () {system. out. println (R. getname () ;}@ testpublic void testgetcustomers () {for (customer C: customerservice. getcustomers () {system. out. println (C. getname ());}}}