SSM框架原理以及流程
Posted You295
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了SSM框架原理以及流程相关的知识,希望对你有一定的参考价值。
SSM框架原理以及流程
一:原理
1.springmvc:
1).客户端发送请求到DispacherServlet(分发器)
2).由DispacherServlet控制器查询HanderMapping,找到处理请求的Controller
3).Controller调用业务逻辑处理后,返回ModelAndView
4).DispacherSerclet查询视图解析器,找到ModelAndView指定的视图
5).视图负责将结果显示到客户端
2.spring
平时开发接触最多的估计就是IOC容器,它可以装载bean(也就是我们Java中的类,当然也包括service dao里面的),有了这个机制,我们就不用在每次使用这个类的时候为它初始化,很少看到关键字new。另外spring的aop,事务管理等等都是我们经常用到的。
3.Mybatis
mybatis是对jdbc的封装,它让数据库底层操作变的透明。mybatis的操作都是围绕一个sqlSessionFactory实例展开的。mybatis通过配置文件关联到各实体类的Mapper文件,Mapper文件中配置了每个类对数据库所需进行的sql语句映射。在每次与数据库交互时,通过sqlSessionFactory拿到一个sqlSession,再执行sql命令。
4.各项作用:
SSM框架是spring MVC ,spring和mybatis框架的整合,是标准的MVC模式,将整个系统划分为表现层,controller层,service层,DAO层四层
使用spring MVC负责请求的转发和视图管理
spring实现业务对象管理,mybatis作为数据对象的持久化引擎
二:开发流程
1.新建maven项目
2.配置整合文件
2.1 配置pom.xml文件—引入依赖
<properties>
<project.spring.version>5.3.9</project.spring.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${project.spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${project.spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${project.spring.version}</version>
<scope>test</scope>
</dependency>
<!-- mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.7</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.25</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.2.6</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.32</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.32</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.6</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.20</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.12.4</version>
</dependency>
</dependencies>
2.2 配置web.xml文件
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/mybatis/spring-*.xml</param-value>
</context-param>
<!-- 启动业务loc容器 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 启动mvc容器 -->
<servlet>
<servlet-name>springDispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<!-- springmvc文件位置 -->
<param-value>classpath:spring/mvc/springmvc-*.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springDispatcherServlet</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>
2.3 配置springmvc
<!-- 扫描位置 -->
<context:component-scan base-package="com.dyit.ssm.entity"/>
<!-- 静态资源放行 -->
<mvc:resources location="static/" mapping="static/**"/>
<!-- 驱动注解 -->
<mvc:annotation-driven/>
2.4 配置mybatis
1).配置spring-mybatis.xml
<!-- 管理范围 -->
<context:component-scan base-package="com.dyit.ssm">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<context:property-placeholder location="classpath:spring/mybatis/druid/druid.properties"/>
<!-- 数据源 -->
<bean id="dataSource"
class="com.alibaba.druid.pool.DruidDataSource">
<property name="url" value="${druid.url}" />
<property name="username" value="${druid.username}" />
<property name="password" value="${druid.password}" />
<property name="driverClassName" value="${druid.driver}" />
</bean>
<!-- 容器创建SqlSessionFactory -->
<bean id="sqlSessionFactory"
class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="typeAliasesPackage" value="com.dyit.ssm.entity"/>
<property name="mapperLocations" value="classpath:spring/mybatis/mapper/*.mapper.xml"/>
</bean>
<!-- 配置接口 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.dyit.ssm.mapper"/>
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
</bean>
<!-- 事务 -->
<bean id="txManger" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
<!-- 让spring管理起来 -->
<tx:annotation-driven transaction-manager="txManger"/>
2).配置druid.properties 数据源(数据库相关配置)
druid.url=jdbc:mysql://192.168.1.8:3306/book_db?useSSL=false&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true
druid.username=root
druid.password=12345
druid.driver=com.mysql.cj.jdbc.Driver
3.配置Book.mapper.xml(数据库的映射类)
在此我以数据库的 增删改查 为例
<mapper namespace="com.dyit.ssm.mapper.IBookMapper">
<sql id="findAllBook">
SELECT * FROM book_tab
</sql>
<resultMap type="Book" id="BookMap">
<id property="id" column="book_id" />
<result property="title" column="book_title" />
<result property="price" column="book_price" />
<result property="author" column="book_author" />
</resultMap>
<insert id="save">
INSERT INTO book_tab(book_title,book_author,book_price)
VALUES(#{title},#{author},#{price})
</insert>
<delete id="deleteById">
DELETE FROM book_tab WHERE book_id=#{id}
</delete>
<insert id="update">
UPDATE book_tab SET book_title=#{title},
book_author=#{author},
book_price=#{price}
WHERE book_id=#{id}
</insert>
<select id="findAll" resultMap="BookMap">
<include refid="findAllBook" />
</select>
</mapper>
3.java代码—测试
1)写实体类
@Alias("Book") //别名
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Book {
private Integer id; //id
private String title; //书名
private double price; //价格
private String author; //作者
}
2)写mapper类–对数据库的操作接口
@Mapper
public interface IBookMapper {
void save(Book book); //添加
void deleteById(int id); //根据id删除
void update(Book book); //修改
List<Book> findAll(); //全查询
}
3)写service接口
public interface IBookService {
void save(Book book); //添加
void deleteById(int id); //根据id删除
void update(Book book); //修改
List<Book> findAll();
}
4)写service接口的实现类
@Service
public class BookServiceImpl implements IBookService{
@Autowired
private IBookMapper mapper; //注入mapper
@Override
public void save(Book book) {
mapper.save(book);
}
@Override
public void deleteById(int id) {
mapper.deleteById(id);
}
@Override
public void update(Book book) {
mapper.update(book);
}
@Override
public List<Book> findAll() {
return mapper.findAll();
}
}
5)写service测试类
@RunWith(SpringJUnit4ClassRunner.class) //测试注解
@ContextConfiguration(locations = "classpath:spring/mybatis/spring-mybatis.xml") //控制文件路径
public class ssmTest {
@Autowired
private IBookService ibs; //注入service
@Test
public void testSave() { //添加
ibs.save(new Book(4, "西游外传", 66.66, "孙悟空"));
}
@Test
public void testDeleteById() { //删除
ibs.deleteById(2);;
}
@Test
public void testUpdate() { //修改
ibs.save(new Book(4, "西游前传", 88.66, "唐三藏"));
}
@Test
public void testFindAll() { //全查询
System.out.println(ibs.findAll());
}
}
6.以添加图书为例查看测试结果展示
注:因没有写日志配置类,故报红
成功添加进数据库
以上是关于SSM框架原理以及流程的主要内容,如果未能解决你的问题,请参考以下文章