- 整个项目使用Spring+Mybatis实现
- 基于Maven管理项目
- 主要的功能实现:登录及商品信息的CRUD操作。
1.创建项目,注入依赖,配置spring。
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>per.lc</groupId> <artifactId>shopManageSystem</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>shopManageSystem Maven Webapp</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> //单元测试 <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>org.apache.tomcat</groupId> <artifactId>tomcat-jsp-api</artifactId> // 导入了servlet(Http)/jsp/el这三个包 <version>9.0.27</version> </dependency> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> //标签库<foreach>... <version>1.2</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> //spring的web容器。WebapplicationContext对象,来获取spring中管理的对象 <version>5.1.9.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> //spring的对象关系映射 <version>5.1.9.RELEASE</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> //aop框架,进行动态代理 <version>1.9.4</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> //封装jdbc的一个持久层的框架 <version>3.4.4</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> //spring整合mybatis,接口由mybatis提供 <version>3.4.3</version> </dependency> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> //数据库的连接池 <version>0.9.5.4</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> //mysql的数据库连接(Driver,Connection对象) <version>8.0.13</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>4</version> </dependency> <!-- https://mvnrepository.com/artifact/net.sf.json-lib/json-lib --> <dependency> <groupId>net.sf.json-lib</groupId> <artifactId>json-lib</artifactId> <version>2.4</version> </dependency> </dependencies>
<?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" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <context:component-scan base-package="per.lc.sms"/> <!-- 数据源配置--> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"></bean> <!-- sessionFactory--> <bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="typeAliasesPackage" value="per.lc.sms.entity"/> <property name="dataSource" ref="dataSource"/> </bean> <!-- 数据访问接口--> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="per.lc.sms.dao"/> <property name="sqlSessionFactoryBeanName" value="sessionFactory"/> </bean> <!-- 事务管理--> <bean id="transaction" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!-- 基于tx的开启事务注解--> <tx:annotation-driven transaction-manager="transaction"/> </beans>
2.c3p0的配置,在前面加上" c3p0. ",在数据源的配置中就可以直接读取了。
c3p0.driverClass=com.mysql.cj.jdbc.Driver c3p0.jdbcUrl=jdbc:mysql://localhost:3306/shop?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC c3p0.user=root c3p0.password=123456 c3p0.maxPoolSize=20 c3p0.minPoolSize=2 c3p0.initialPoolSize=2 c3p0.maxIdleTime=60
3.框架的联合测试,查询所有的商品类别。
//实体类
public class ArticleType {
private String code;
private String name;
private String remark;
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRemark() {
return remark;
}
public void setRemark(String remark) {
this.remark = remark;
}
@Override
public String toString() {
return "ArticleType{" +
"code='" + code + '\'' +
", name='" + name + '\'' +
", remark='" + remark + '\'' +
'}';
}
}
//dao层
@Repository("articleTypeDao") public interface ArticleTypeDao { @Select("select * from ec_article_type")//使用注解的方式 public List<ArticleType> select(); }
//业务层接口及其实现类 public interface ArticleTypeService { public List<ArticleType> getAll(); } @Service("articleTypeService") public class ArticleTypeServiceImp implements ArticleTypeService { @Resource private ArticleTypeDao articleTypeDao; @Override public List<ArticleType> getAll() { return articleTypeDao.select(); } }
//servlet
@WebServlet("/getArticleTypes") public class ArticleTypeServlet extends HttpServlet { private ArticleTypeService articleTypeService; @Override public void init() throws ServletException { super.init(); ServletContext servletContext=this.getServletContext(); WebApplicationContext context= WebApplicationContextUtils.getWebApplicationContext(servletContext); //这个servlet与之前项目的controller层代码怎么不一样,为什么要去上下文中getBean(),不能从spring中获取吗? articleTypeService= (ArticleTypeService) context.getBean("articleTypeService"); } @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { super.service(req, resp); List<ArticleType> articleTypes=articleTypeService.getAll(); System.out.println(articleTypes); } }
代码中的困惑:这个servlet与之前项目的controller层代码怎么不一样,为什么要去上下文中getBean(),不能从spring中获取吗?
答:是不一样的,这个类是继承了HttpServlet类,而之前的controller层代码,是一个普通的类,是把HttpServlet子类作为类中一个方法的参数。
//web.xml配置
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
<!--提取spring的配置文件-->
<context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/application.xml</param-value> </context-param> <!-- 核心监听器--> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> </web-app>
核心监听器的作用:为了在项目启动后能够拿到业务层的对象来执行getAll()方法,需要将application.xml文件装配到spring中。他的作用就是监听到项目启动后,将配置文件装配到spring中。
4.运行中发生的异常:
- -CannotGetJdbcConnectionException
最后发现是c3p0的配置文件有问题:
修改前:c3p0.jdbcUrl=jdbc:mysql://localhost:3306/shop?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
修改后:c3p0.jdbcUrl=jdbc:mysql://localhost:3306/shop?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC,只保留&符号即可。
5.最终成功,查询结果:
。。。。