1. spring核心配置文件：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 读取占位符配置文件，和mybatis的一样 -->
<context:property-placeholder location="classpath:db.properties" /> <!-- apache的连接池依赖类，pom里配置引入commons-dbcp -->
<!-- 这里需要占位符配置url、username、password -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${db.driver}" />
<property name="url" value="${db.url}" />
<property name="username" value="${db.username}" />
<property name="password" value="${db.password}" />
</bean> <!-- spring提供的jdbc template方便dao层编写，pom引入依赖spring-jdbc -->
<!-- 这里需要注入上面生成好的数据库连接池dataSource -->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"></property>
</bean> <!-- 自己编写的持久层，内置一个叫template的属性（必须要有setter） -->
<!-- 往属性template注入上面生成好的jdbcTemplate -->
<bean id="userDao" class="dao.daoXmlImpl">
<property name="template" ref="jdbcTemplate"></property>
</bean> <!-- 自己编写的业务层，内置一个叫dao的属性（必须要有setter） -->
<!-- 往属性dao注入上面生成好的userDao -->
<bean id="userService" class="service.xmlImpl">
<property name="dao" ref="userDao"></property>
</bean> </beans>
2.POJO类
public class User {
private int id;
private String username;
@Override
public String toString() {
return "User [id=" + id + ", username=" + username + ", address=" + address + "]";
}
private String address;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}3. dao类
public class daoXmlImpl implements userDao {
private JdbcTemplate template;
// 留一个dao的setter让Spring帮忙注入jdbcTemplate
public void setTemplate(JdbcTemplate template) {
this.template = template;
}
@Override
public User getUserById(int id) {
// 业务SQL
String sql = "SELECT * FROM user WHERE id = ?";
// 参数数组
Object[] args = { id };
// 使用jdbcTemplate来查询数据库
return template.queryForObject(sql, args, new RowMapper<User>() {
@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user = new User();
user.setId(rs.getInt("id"));
user.setUsername(rs.getString("username"));
user.setAddress(rs.getString("address"));
return user;
}
});
}
}4.service类
public class xmlImpl implements userService{
private userDao dao;
// 留一个dao的setter让Spring帮忙注入userDao
public void setDao(userDao dao) {
this.dao = dao;
}
@Override
public User findUser(int id) {
return dao.getUserById(id);
}
}5.使用类（这里用servlet）
public class userView extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 获取参数
String id = request.getParameter("id");
// 获取Spring IOC容器
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
// 通过Spring IOC容器获取 service bean
userService service = context.getBean(userService.class);
// 调用service的方法，获取user
User user = service.findUser(Integer.parseInt(id));
// 响应，打印user
response.setContentType("application/json;charset=utf-8");
response.getWriter().print(user);
}
}