Spring DAO之JDBC
Spring提供的DAO(數(shù)據(jù)訪問對象)支持主要的目的是便于以標(biāo)準(zhǔn)的方式使用不同的數(shù)據(jù)訪問技術(shù)， 如JDBC，Hibernate或者JDO等。它不僅可以讓你方便地在這些持久化技術(shù)間切換， 而且讓你在編碼的時候不用考慮處理各種技術(shù)中特定的異常。
為了便于以一種一致的方式使用各種數(shù)據(jù)訪問技術(shù)，如JDBC、JDO和Hibernate， Spring提供了一套抽象DAO類供你擴展。這些抽象類提供了一些方法，通過它們你可以 獲得與你當(dāng)前使用的數(shù)據(jù)訪問技術(shù)相關(guān)的數(shù)據(jù)源和其他配置信息。
Dao支持類：
JdbcDaoSupport - JDBC數(shù)據(jù)訪問對象的基類。 需要一個DataSource，同時為子類提供 JdbcTemplate。
HibernateDaoSupport - Hibernate數(shù)據(jù)訪問對象的基類。 需要一個SessionFactory，同時為子類提供 HibernateTemplate。也可以選擇直接通過 提供一個HibernateTemplate來初始化， 這樣就可以重用后者的設(shè)置，例如SessionFactory， flush模式，異常翻譯器（exception translator）等等。
JdoDaoSupport - JDO數(shù)據(jù)訪問對象的基類。 需要設(shè)置一個PersistenceManagerFactory， 同時為子類提供JdoTemplate。
JpaDaoSupport - JPA數(shù)據(jù)訪問對象的基類。 需要一個EntityManagerFactory，同時 為子類提供JpaTemplate。
本節(jié)主要討論Sping對JdbcDaoSupport的支持。
下面是個例子：
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drop table if exists user; /*==============================================================*/ /* Table: user */ /*==============================================================*/ create table user( id bigint AUTO_INCREMENT not null, name varchar(24), age int, primary key (id) ); |
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public class User { private Integer id; private String name; private Integer age; 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; } } |
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/** * Created by IntelliJ IDEA.<br> * <b>User</b>: leizhimin<br> * <b>Date</b>: 2008-4-22 15:34:36<br> * <b>Note</b>: DAO接口 */public interface IUserDAO { public void insert(User user); public User find(Integer id); } import javax.sql.DataSource; import java.sql.Connection; import java.sql.SQLException; /** * Created by IntelliJ IDEA.<br> * <b>Note</b>: 基類DAO，提供了數(shù)據(jù)源注入 */public class BaseDAO { private DataSource dataSource; public DataSource getDataSource() { return dataSource; } public void setDataSource(DataSource dataSource) { this.dataSource = dataSource; } public Connection getConnection() { Connection conn = null; try { conn = dataSource.getConnection(); } catch (SQLException e) { e.printStackTrace(); } return conn; } } /** * Created by IntelliJ IDEA.<br> * <b>User</b>: leizhimin<br> * <b>Date</b>: 2008-4-22 15:36:04<br> * <b>Note</b>: DAO實現(xiàn) */public class UserDAO extends BaseDAO implements IUserDAO { public JdbcTemplate getJdbcTemplate(){ return new JdbcTemplate(getDataSource()); } public void insert(User user) { String name = user.getName(); int age = user.getAge().intValue(); // jdbcTemplate.update("INSERT INTO user (name,age) " // + "VALUES('" + name + "'," + age + ")"); String sql = "insert into user(name,age) values(?,?)"; getJdbcTemplate().update(sql,new Object[]{name,age}); } public User find(Integer id) { List rows = getJdbcTemplate().queryForList( "SELECT * FROM user WHERE id=" + id.intValue()); Iterator it = rows.iterator(); if (it.hasNext()) { Map userMap = (Map) it.next(); Integer i = new Integer(userMap.get("id").toString()); String name = userMap.get("name").toString(); Integer age = new Integer(userMap.get("age").toString()); User user = new User(); user.setId(i); user.setName(name); user.setAge(age); return user; } return null; } } |
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<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING/DTD BEAN/EN" "http://www.springframework.org/dtd/spring-beans.dtd"> <beans> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" singleton="true"> <property name="driverClassName"> <value>com.mysql.jdbc.Driver</value> </property> <property name="url"> <value>jdbc:mysql://localhost:3306/springdb</value> </property> <property name="username"> <value>root</value> </property> <property name="password"> <value>leizhimin</value> </property> </bean> <bean id="baseDAO" class="com.lavasoft.springnote.ch05_jdbc03_temp.BaseDAO" abstract="true"> <property name="dataSource"> <ref bean="dataSource"/> </property> </bean> <bean id="userDAO" class="com.lavasoft.springnote.ch05_jdbc03_temp.UserDAO" parent="baseDAO"> </bean> </beans> |
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import org.springframework.context.ApplicationContext; import org.springframework.context.support.FileSystemXmlApplicationContext; /** * Created by IntelliJ IDEA.<br> * <b>User</b>: leizhimin<br> * <b>Date</b>: 2008-4-22 15:59:18<br> * <b>Note</b>: 測試類，客戶端 */public class SpringDAODemo { public static void main(String[] args) { ApplicationContext context = new FileSystemXmlApplicationContext("D:\\_spring\\src\\com\\lavasoft\\springnote\\ch05_jdbc03_temp\\bean-jdbc-temp.xml"); User user = new User(); user.setName("hahhahah"); user.setAge(new Integer(22)); IUserDAO userDAO = (IUserDAO) context.getBean("userDAO"); userDAO.insert(user); user = userDAO.find(new Integer(1)); System.out.println("name: " + user.getName()); } } |
運行結(jié)果：
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log4j:WARN No appenders could be found for logger (org.springframework.core.CollectionFactory). log4j:WARN Please initialize the log4j system properly. name: jdbctemplate Process finished with exit code 0 |
Spring DAO之Hibernate
HibernateDaoSupport - Hibernate數(shù)據(jù)訪問對象的基類。 需要一個SessionFactory，同時為子類提供 HibernateTemplate。也可以選擇直接通過 提供一個HibernateTemplate來初始化， 這樣就可以重用后者的設(shè)置，例如SessionFactory， flush模式，異常翻譯器（exception translator）等等。
本節(jié)主要討論Sping對HibernateTemplate的支持。
下面是個例子：
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drop table if exists user; /*==============================================================*/ /* Table: user */ /*==============================================================*/ create table user( id bigint AUTO_INCREMENT not null, name varchar(24), age int, primary key (id) ); |
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/** * Created by IntelliJ IDEA.<br> * <b>Note</b>: Hiberante實體類 */public class User { private Integer id; private String name; private Integer age; 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; } } |
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<?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="com.lavasoft.springnote.ch06_hbm_02deTx.User" table="user"> <id name="id" column="id"> <generator class="native"/> </id> <property name="name" column="name"/> <property name="age" column="age"/> </class> </hibernate-mapping> |
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/** * Created by IntelliJ IDEA.<br> * <b>User</b>: leizhimin<br> * <b>Date</b>: 2008-4-23 15:37:43<br> * <b>Note</b>: DAO接口 */public interface IUserDAO { public void insert(User user); public User find(Integer id); } import org.hibernate.SessionFactory; import org.springframework.orm.hibernate3.HibernateTemplate; /** * Created by IntelliJ IDEA.<br> * <b>User</b>: leizhimin<br> * <b>Date</b>: 2008-4-23 15:15:55<br> * <b>Note</b>: DAO實現(xiàn) */public class UserDAO implements IUserDAO { private HibernateTemplate hibernateTemplate; public void setSessionFactory(SessionFactory sessionFactory) { this.hibernateTemplate =new HibernateTemplate(sessionFactory); } public void insert(User user) { hibernateTemplate.save(user); System.out.println("所保存的User對象的ID:"+user.getId()); } public User find(Integer id) { User user =(User) hibernateTemplate.get(User.class, id); return user; } } |
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<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING/DTD BEAN/EN" "http://www.springframework.org/dtd/spring-beans.dtd"> <beans> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName"> <value>com.mysql.jdbc.Driver</value> </property> <property name="url"> <value>jdbc:mysql://localhost:3306/springdb</value> </property> <property name="username"> <value>root</value> </property> <property name="password"> <value>leizhimin</value> </property> </bean> <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean" destroy-method="close"> <property name="dataSource"> <ref bean="dataSource"/> </property> <property name="mappingResources"> <list> <value>com/lavasoft/springnote/ch06_hbm_02proTx/User.hbm.xml</value> </list> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect"> org.hibernate.dialect.MySQLDialect </prop> </props> </property> </bean> <bean id="userDAO" class="com.lavasoft.springnote.ch06_hbm_02proTx.UserDAO"> <property name="sessionFactory"> <ref bean="sessionFactory"/> </property> </bean> </beans> |
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import org.springframework.context.ApplicationContext; import org.springframework.context.support.FileSystemXmlApplicationContext; /** * Created by IntelliJ IDEA.<br> * <b>Note</b>: 測試類、客戶端 */public class SpringHibernateDemo { public static void main(String[] args) { ApplicationContext context =new FileSystemXmlApplicationContext("D:\\_spring\\src\\com\\lavasoft\\springnote\\ch06_hbm_02proTx\\bean-hbm_tx.xml"); // 建立DAO物件 IUserDAO userDAO = (IUserDAO) context.getBean("userDAO"); User user = new User(); user.setName("caterpillar"); user.setAge(new Integer(30)); userDAO.insert(user); user = userDAO.find(new Integer(1)); System.out.println("name: " + user.getName()); } } |
運行結(jié)果：
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log4j:WARN No appenders could be found for logger (org.springframework.core.CollectionFactory). log4j:WARN Please initialize the log4j system properly. 所保存的User對象的ID:18 name: jdbctemplate Process finished with exit code 0 |
