EJB 建立串連到執行SQL過程

1 在項目source folder下,建立persistent.xml檔案.

Project Name

                --| src

                         --|persistence.xml

2 編寫persistent.xml檔案,內容符合如下格式.

<?xml version="1.0" encoding="UTF-8"?><persistence version="1.0"xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"><persistence-unit name="CICI_PERSISTENCE_UNIT" transaction-type="RESOURCE_LOCAL"><provider>org.eclipse.persistence.jpa.PersistenceProvider</provider><class>com.cici.crm.migration.model.crm.CrmCardInstance</class><class>com.cici.crm.migration.model.crm.CrmApplicationInstance</class> <properties><property name="eclipselink.jdbc.native-sql" value="true"/><property name="eclipselink.jdbc.batch-writing" value="JDBC"/><property name="eclipselink.logging.level" value="OFF"/><property name="eclipselink.target-database" value="Oracle" /> <property name="eclipselink.jdbc.url" value="jdbc:oracle:thin:@localhost:1521:CICIDB" /><property name="eclipselink.jdbc.driver" value="oracle.jdbc.driver.OracleDriver" /><property name="eclipselink.jdbc.user" value="ADMCICI" /><property name="eclipselink.jdbc.password" value="ADMCICI" /><property name="eclipselink.ddl-generation" value="none" /></properties></persistence-unit></persistence>

 

3 建立包含DB建立串連參數的Map

Map<String,String> properties = new HashMap<String,String>();properties.put("eclipselink.jdbc.user", Configuration.getInstance ().getValue (Configuration.OTAM_DATABASE_USERNAME)); properties.put      

("eclipselink.jdbc.password",Configuration.getInstance().getValue(Configuration.OTAM_DATABASE_PASSWORD));                                                                                                                                                                                                                    

4 建立EntityManagerFactory

EntityManagerFactory rcaFactory = Persistence.createEntityManagerFactory(CICI_PERSISTENCE_UNIT, properties);

5 建立 EntityManager

  

EntityManager entityManager = rcaFactory.createEntityManager ();

6 建立 EntityTransaction 並開啟串連

  

entityManager.getTransaction().begin();

7 建立Query並執行sql語句

Query query = entityManager.createNamedQuery(sql);

query.executeUpdate ();

8 提交事務

 

entityManager.getTransaction ().commit ();

 

9 關閉串連

 

entityManger.close();

 ciciFactory.close();