一，场景：编写一个用户管理的服务层，包括增加用户、删除用户和查询用户等等，而且用户信息以关系型数据库形式存储。分析：这是一个典型的应用服务，涉及到业务层（Business Objects Layer）、数据库访问层（DB Access）和存储层（EIS）。采用典型的架构：BO+DAODAO采用Spring提供的JdbcTemplate来进行封装。
二，具体实现
1）用户类Userpublic class User{ private String username; private String email; private Date birthday; public User(){} … 相应的setter/getter方法。 } 这是一个简单的bean类，记录用户的信息。 2）数据库访问类：UserDao
public interface UserDao { public void save(User user); public void remove(String username); public User searchByName(String username); } 这是数据库访问的接口类，定义了对用户的数据库操作，其实现类是UserDaoJdbc UserDaoJdbc类
public class UserDaoJdbc extends JdbcDaoSupport implements UserDao { public UserDaoJdbc() { super(); } public void save(User user) { getJdbcTemplate().update( "insert into SAMPLE_USER values (?,?,?)", new Object[] { user.getUsername(), user.getEmail(), user.getBirthday() }); } ... }3）业务类UserManageServicepublic interface UserManageService { public void saveUser(User user); public void removeUser(String username); public User getUserByName(String username); } 这是用户的业务类接口，定义了和用户相关的一些业务操作，其实现类UserManageServiceImpl
实现类UserManageServiceImpl
public class UserManageServiceImpl implements UserManageService {
private UserDao udao;
public UserManageServiceImpl() { super(); } public void saveUser(User user) { udao.save(user); } public UserDao getUdao() { return udao; } public void setUdao(UserDao udao) { this.udao = udao; }}
4）Spring bean描述文件配置
<beans> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName"> <value>oracle.jdbc.driver.OracleDriver</value> </property> <property name="url"> <value>jdbc:oracle:thin:@172.16.4.219:1521:orcl</value> </property> <property name="username"> <value>zhangbo</value> </property> <property name="password"> <value>password</value> </property> </bean> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource"> <ref bean="dataSource"/> </property> </bean> <bean id="userdao" class="sample.spring.dao.UserDaoJdbc"> <property name="dataSource"> <ref bean="dataSource"/> </property> </bean> <bean id="userManageService" class="sample.spring.service.UserManageServiceImpl"> <property name="udao"> <ref bean="userdao"/> </property> </bean></beans>
5）数据中存储用户的表SAMPLE_USERusername varchar2(30) not null,email varchar2(50) not null,birthday date
6）通过单元测试来验证UserManageService中的操作：public class UserManageServiceTest extends TestCase {
private UserManageService service;
private static Log logger = LogFactory.getLog(UserManageServiceTest.class);
protected void setUp() throws Exception { super.setUp(); service = (UserManageService) SpringContextUtil .getBean("userManageService"); } public void testSaveAndSearchAndRemoveUser() throws Exception { User user = new User(); user.setUsername("zhangsan"); user.setEmail("zhangsan@test.com"); user.setBirthday(new Date()); service.saveUser(user); logger.debug("存入一个新用户:" + user); User userFromDb = service.getUserByName("zhangsan"); assertNotNull(userFromDb); assertEquals(userFromDb.getEmail(), "zhangsan@test.com"); logger.debug("从数据库中查到用户:" + userFromDb); service.removeUser("zhangsan"); logger.debug("从数据库删除用户:" + userFromDb); } protected void tearDown() throws Exception { super.tearDown(); }}
