笔记要点&出错分析与总结
POJO(Plain Ordinary Java Object)简单的Java对象,实际就是普通JavaBeans,
工程组织
(AirportService为机场服务站接口,定义了 List<Airport> show();
package com03.service; import com03.bean.Airport; import org.apache.ibatis.annotations.Select; import java.util.List; public interface AirportService { List<Airport> show(); }
AirportserviceImpl 是该接口的提供具体的实现类,重写接口的方法,并有get/set 方法
public List<Airport> show() {
return airportMapper.selectAll();
}
package com03.service; import com03.bean.Airport; import com03.mapper.AirportMapper; import java.util.List; public class AirportServiceImpl implements AirportService{ private AirportMapper airportMapper; @Override public List<Airport> show() { return airportMapper.selectAll(); } public AirportMapper getAirportMapper() { return airportMapper; } public void setAirportMapper(AirportMapper airportMapper) { this.airportMapper = airportMapper; } }
AirportMapper接口 实现从数据库查询信息返回List<Airport> )
package com03.mapper; import com03.bean.Airport; import org.apache.ibatis.annotations.Select; import java.util.List; public interface AirportMapper { @Select("select * from airport") public List<Airport> selectAll(); }
具体结构图,并1.导入mybatis所有jar 包 ,spring基本包spring-jdbc,spring-tx,spring-aop,spring-web,spring整合mybatis 的包等.
数据库组织
id airplane_no time price takeoff_id land_id
------ ----------- ------ ------ ---------- ---------
1 波音747 123 100 1 3
2 波音858 56 300 3 2
0.定义Bean类 Airport
package com03.bean; public class Airport { private int id; private String portName; private String cityName; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getPortName() { return portName; } public void setPortName(String portName) { this.portName = portName; } public String getCityName() { return cityName; } public void setCityName(String cityName) { this.cityName = cityName; } @Override public String toString() { return "Airport [id=" + id + ", portName=" + portName + ", cityName=" + cityName + "]"; } }
1.定义接口 (见上面)
2.定义Spring的XML映射文件 applicationContext.xml
<?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:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/beans/spring-beans.xsd"> <!--配置Mybatis的基本登陆信息,连接信息;除了事务方面的--> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="com.mysql.jdbc.Driver"></property> <property name="url" value="jdbc:mysql://localhost:3306/ssm"></property> <property name="username" value="root"></property> <property name="password" value="123456"></property> </bean> <bean id="factory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"></property> </bean> <!--扫描相当于mybatis.xml中的mapper的package标签; 扫描指定文件夹下的全部配置文件/接口,会自动为接口创建对象--> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!--要扫描那个包--> <property name="basePackage" value="com03.mapper"></property> <!--和factory 产生关系--> <property name="sqlSessionFactory" ref="factory"></property> </bean> <!--ref="airportMapper" ,上一步扫描完全局配置和接口文件后,会自动创建该bean--> <!--由Spring --> <bean id="airportService" class="com03.service.AirportServiceImpl"> <property name="airportMapper" ref="airportMapper"></property> </bean> </beans>
3.编写测试代码 test01 (配置文件不在默认的SRC下, 在 com03/conf/applicationContext.xml)
package com03.test; import com03.bean.Airport; import com03.service.AirportServiceImpl; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import java.util.List; public class test01 { public static void main(String[] args) { //创建Spring 容器 ,默认去根目录开始寻找 ApplicationContext ac=new ClassPathXmlApplicationContext("com03/conf/applicationContext.xml"); String[] names = ac.getBeanDefinitionNames(); for (String name:names ) { System.out.println("★Spring自动创建了:"+" "+name); } AirportServiceImpl bean = ac.getBean("airportService", AirportServiceImpl.class); List<Airport> list = bean.show(); System.out.println("★"+list); } }
测试结果
★Spring自动创建了: dataSource
★Spring自动创建了: factory
★Spring自动创建了: org.mybatis.spring.mapper.MapperScannerConfigurer#0
★Spring自动创建了: airportService
★Spring自动创建了: airportMapper
★Spring自动创建了: org.springframework.context.annotation.internalConfigurationAnnotationProcessor
★Spring自动创建了: org.springframework.context.annotation.internalAutowiredAnnotationProcessor
★Spring自动创建了: org.springframework.context.annotation.internalRequiredAnnotationProcessor
★Spring自动创建了: org.springframework.context.annotation.internalCommonAnnotationProcessor
★Spring自动创建了: org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor
★Spring自动创建了: org.springframework.context.annotation.ConfigurationClassPostProcessor.enhancedConfigurationProcessor
DEBUG 12-08 10:44:15,527 JDBC Connection [com.mysql.jdbc.JDBC4Connection@399f45b1] will not be managed by Spring (SpringManagedTransaction.java:87) DEBUG 12-08 10:44:15,532 ==> Preparing: select * from airport (BaseJdbcLogger.java:139) DEBUG 12-08 10:44:15,556 ==> Parameters: (BaseJdbcLogger.java:139) DEBUG 12-08 10:44:15,572 <== Total: 3 (BaseJdbcLogger.java:139) DEBUG 12-08 10:44:15,572 Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@3eb7fc54] (SqlSessionUtils.java:193) DEBUG 12-08 10:44:15,572 Returning JDBC Connection to DataSource (DataSourceUtils.java:327) ★[Airport [id=1, portName=首都机场, cityName=北京], Airport [id=2, portName=南阳机场, cityName=南阳],
Airport [id=3, portName=虹桥机场, cityName=上海]]