SSM框架复习——SpringMVC

朴灿烈づ我的快乐病毒、 2022-12-10 02:27 179阅读 0赞

### SSM框架复习3 ###

*  SpringMVC
 *   *  MVC
     *  SpringMVC
     *  SpringMVC执行原理
     *  SpringMVC执行流程
     *  ResultFul
     *  整合SSM（用户管理）

# SpringMVC #

## MVC ##

*  MVC是模型(Model)、视图(View)、控制器(Controller)的简写，是一种软件设计规范。
 *  是将业务逻辑、数据、显示分离的方法来组织代码。
 *  MVC主要作用是降低了视图与业务逻辑间的双向偶合。
 *  MVC不是一种设计模式，MVC是一种架构模式。当然不同的MVC存在差异。

**Model（模型）：** 数据模型，提供要展示的数据，因此包含数据和行为，可以认为是领域模型或JavaBean组件（包含数据和行为），不过现在一般都分离开来：Value Object（数据Dao） 和 服务层（行为Service）。也就是模型提供了模型数据查询和模型数据的状态更新等功能，包括数据和业务。

**View（视图）：** 负责进行模型的展示，一般就是我们见到的用户界面，客户想看到的东西。

**Controller（控制器）：** 接收用户请求，委托给模型进行处理（状态改变），处理完毕后把返回的模型数据返回给视图，由视图负责展示。也就是说控制器做了个调度员的工作。

最典型的MVC就是JSP + servlet + javabean的模式。  
职责分析：

**Controller：控制器**

1.  取得表单数据
2.  调用业务逻辑
3.  转向指定的页面

**Model：模型**

1.  业务逻辑
2.  保存数据的状态

**View：视图**

1.  显示页面

## SpringMVC ##

***Spring MVC是Spring Framework的一部分，是基于Java实现MVC的轻量级Web框架。***  
官方文档：[https://docs.spring.io/spring/docs/4.3.24.RELEASE/spring-framework-reference/html/mvc.html][https_docs.spring.io_spring_docs_4.3.24.RELEASE_spring-framework-reference_html_mvc.html]  
**Spring MVC的特点：**

1.  轻量级，简单易学
2.  高效 , 基于请求响应的MVC框架
3.  与Spring兼容性好，无缝结合
4.  约定优于配置
5.  功能强大：RESTful、数据验证、格式化、本地化、主题等
6.  简洁灵活

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNTEwNTUx_size_16_color_FFFFFF_t_70_pic_center]

Spring的web框架围绕DispatcherServlet \[ 调度Servlet \] 设计。

SpringMVC的原理如下图所示：  
当发起请求时被前置的控制器拦截到请求，根据请求参数生成代理请求，找到请求对应的实际控制器，控制器处理请求，创建数据模型，访问数据库，将模型响应给中心控制器，控制器使用模型与视图渲染视图结果，将结果返回给中心控制器，再将结果返回给请求者。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNTEwNTUx_size_16_color_FFFFFF_t_70_pic_center 1]

## SpringMVC执行原理 ##

![实线表示SpringMVC框架提供的技术，不需要开发者实现，虚线表示需要开发者实现。][SpringMVC]

1.  DispatcherServlet表示前置控制器，是整个SpringMVC的控制中心。用户发出请求，DispatcherServlet接收请求并拦截请求。
    
        我们假设请求的url为 : http://localhost:8080/SpringMVC/hello
        
        如上url拆分成三部分：http://localhost:8080服务器域名
        SpringMVC部署在服务器上的web站点
        hello表示控制器

通过分析，如上url表示为：请求位于服务器localhost:8080上的SpringMVC站点的hello控制器。

1.  HandlerMapping为处理器映射。DispatcherServlet调用
2.  HandlerMapping,HandlerMapping根据请求url查找Handler。
3.  HandlerExecution表示具体的Handler,其主要作用是根据url查找控制器，如上url被查找控制器为：hello。
4.  HandlerExecution将解析后的信息传递给DispatcherServlet,如解析控制器映射等。
5.  HandlerAdapter表示处理器适配器，其按照特定的规则去执行Handler。
6.  Handler让具体的Controller执行。
7.  Controller将具体的执行信息返回给HandlerAdapter,如ModelAndView。
8.  HandlerAdapter将视图逻辑名或模型传递给DispatcherServlet。
9.  DispatcherServlet调用视图解析器(ViewResolver)来解析HandlerAdapter传递的逻辑视图名。
10. 视图解析器将解析的逻辑视图名传给DispatcherServlet。
11. DispatcherServlet根据视图解析器解析的视图结果，调用具体的视图。
12. 最终视图呈现给用户。

## SpringMVC执行流程 ##

先来看一个SpringMVC的小程序  
1、用IDEA创建一个干净的Maven项目，通过添加外部框架支持加入web  
![右击项目可见][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNTEwNTUx_size_16_color_FFFFFF_t_70_pic_center 2]  
2、添加依赖

<dependencies>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>5.2.8.RELEASE</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>servlet-api</artifactId>
                <version>2.5</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>jsp-api</artifactId>
                <version>2.0</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>jstl</artifactId>
                <version>1.2</version>
            </dependency>
        </dependencies>
    
        
        <build>
            <resources>
                <resource>
                    <directory>src/main/resources</directory>
                    <includes>
                        <include>**/*.properties</include>
                        <include>**/*.xml</include>
                    </includes>
                    <filtering>true</filtering>
                </resource>
                <resource>
                    <directory>src/main/java</directory>
                    <includes>
                        <include>**/*.properties</include>
                        <include>**/*.xml</include>
                    </includes>
                    <filtering>true</filtering>
                </resource>
            </resources>
        </build>

2、配置web.xml

<servlet>
            <servlet-name>spring_mvc</servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            
            <init-param>
                <param-name>contextConfigLocation</param-name>
                <param-value>classpath:springmvc-servlet.xml</param-value>
            </init-param>
            <load-on-startup>1</load-on-startup>
        </servlet>
        <servlet-mapping>
            <servlet-name>spring_mvc</servlet-name>
            <url-pattern>/</url-pattern>
            
        </servlet-mapping>
        <absolute-ordering />

注：这里要加上`<absolute-ordering />`否则会报错（坑）：[https://blog.csdn.net/qq\_41510551/article/details/108756185][https_blog.csdn.net_qq_41510551_article_details_108756185]  
配置好后创建spring配置：springmvc-servlet.xml

编写controller类

@Controller
    @RequestMapping("/test")
    public class HelloController { 
        //请求地址：test/hello
        @RequestMapping("/hello")
        String GetHello(Model model){ 
            //向模型中添加属性msg与值，可以在JSP页面中取出并渲染
            model.addAttribute("msg","HelloSpringMVC!");
            ///WEB-INF/jsp/hello.jsp
            return "test";
        }
    }

在WEB-INF下创建jsp文件夹，创建test.jsp，编写`${msg}`即可将代码展示到页面了  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNTEwNTUx_size_16_color_FFFFFF_t_70_pic_center 3]  
**使用springMVC必须配置的三大件：**

**处理器映射器、处理器适配器、视图解析器**

通常，我们只需要手动配置视图解析器，而处理器映射器和处理器适配器只需要开启注解驱动即可，而省去了大段的xml配置

**执行流程图**  
![实线表示SpringMVC框架提供的技术，不需要开发者实现，虚线表示需要开发者实现。][SpringMVC]

## ResultFul ##

**ResultFul是一种风格**  
**概念**

Restful就是一个资源定位及资源操作的风格。不是标准也不是协议，只是一种风格。基于这个风格设计的软件可以更简洁，更有层次，更易于实现缓存等机制。

功能

资源：互联网所有的事物都可以被抽象为资源

资源操作：使用POST、DELETE、PUT、GET，使用不同方法对资源进行操作。

分别对应 添加、 删除、修改、查询。

传统方式操作资源 ：通过不同的参数来实现不同的效果！方法单一，post 和 get

http://127.0.0.1/item/queryItem.action?id=1 查询,GET

http://127.0.0.1/item/saveItem.action 新增,POST

http://127.0.0.1/item/updateItem.action 更新,POST

http://127.0.0.1/item/deleteItem.action?id=1 删除,GET或POST

使用RESTful操作资源 ：可以通过不同的请求方式来实现不同的效果！如下：请求地址一样，但是功能可以不同！

http://127.0.0.1/item/1 查询,GET

http://127.0.0.1/item 新增,POST

http://127.0.0.1/item 更新,PUT

http://127.0.0.1/item/1 删除,DELETE

测试

@Controller
    @RequestMapping("/Rf")
    public class ResultFulController { 
    
        //通过ResultFul风格进行传参：传统：http://localhost:8080/Rf/add?a=4&b=5
        //通过ResultFul风格进行传参：http://localhost:8080/Rf/add/4/5
        //@RequestMapping(name = "/add/{a}/{b}",method = RequestMethod.GET)//method：以get方式进行请求,等价于下面
        @GetMapping("/add/{a}/{b}")
        public String getAdd(@PathVariable int a, @PathVariable int b, Model model){ 
            int res=a+b;
            model.addAttribute("msg","a+b="+res);
            return "test";
        }
    }

## 整合SSM（用户管理） ##

环境配置：IDEA+MYSQL8.0.15+Tomcat9+Maven3.6

1、建立数据库和表

CREATE TABLE `user` (
      `user_id` int(11) NOT NULL AUTO_INCREMENT,
      `user_name` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
      `user_password` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
      `create_time` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
      PRIMARY KEY (`user_id`) USING BTREE,
      KEY `index_name` (`user_name`) USING BTREE
    ) ENGINE=InnoDB AUTO_INCREMENT=216 DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC;
    insert into music.user (user_id,user_name,user_password)
            values (1,"123","123");
            insert into music.user (user_id,user_name,user_password)
            values (2,"1234","123");
            insert into music.user (user_id,user_name,user_password)
            values (3,"1235","123");
            insert into music.user (user_id,user_name,user_password)
            values (4,"1236","123");

2、搭建环境  
（1）创建Maven项目，导入相关依赖，添加外部框架支持加入web，在项目的WEB-INF目录下新建一个lib文件夹，导入相关包

<dependencies>
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
            
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
                <version>3.5.5</version>
            </dependency>
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>8.0.15</version>
            </dependency>
            
            <dependency>
                <groupId>com.mchange</groupId>
                <artifactId>c3p0</artifactId>
                <version>0.9.5.5</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-jdbc</artifactId>
                <version>5.2.8.RELEASE</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>5.2.8.RELEASE</version>
            </dependency>
            
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>servlet-api</artifactId>
                <version>2.5</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>jsp-api</artifactId>
                <version>2.0</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>jstl</artifactId>
                <version>1.2</version>
            </dependency>
            
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis-spring</artifactId>
                <version>2.0.5</version>
            </dependency>
            
            <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.6</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-aop</artifactId>
                <version>5.2.8.RELEASE</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>5.2.8.RELEASE</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
                <version>2.11.2</version>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>1.18.6</version>
            </dependency>
        </dependencies>
    
        
        <build>
            <resources>
                <resource>
                    <directory>src/main/resources</directory>
                    <includes>
                        <include>**/*.properties</include>
                        <include>**/*.xml</include>
                    </includes>
                    <filtering>true</filtering>
                </resource>
                <resource>
                    <directory>src/main/java</directory>
                    <includes>
                        <include>**/*.properties</include>
                        <include>**/*.xml</include>
                    </includes>
                    <filtering>true</filtering>
                </resource>
            </resources>
        </build>

3、创建基本架构

*  com.fly.pojo
 *  com.fly.mapper
 *  com.fly.service
 *  com.fly.controller
 *  mybatis\_config.xml
 *  applicationContext.xml

Mybatis层编写

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
    <configuration>
        
        <settings>
            <setting name="logImpl" value="STDOUT_LOGGING"/>
        </settings>
        
        <typeAliases>
            <package name="com.fly.pojo"/>
        </typeAliases>
        <mappers>
            <mapper resource="com/fly/mapper/UserMapper.xml"/>
        </mappers>
    </configuration>

数据库配置

jdbc.drive=com.mysql.cj.jdbc.Driver
    jdbc.url=jdbc:mysql://localhost:3306/music?useSSL=true&useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8
    jdbc.username=root
    jdbc.password=password

编写数据库对应的实体类com.fly.pojo.User.java

@Data //lombok
    public class User { 
        private int user_id;
        private String user_name;
        private String user_password;
        private Date create_time;
    
        public User() { 
        }
    
        public User(int user_id, String user_name, String user_password) { 
            this.user_id = user_id;
            this.user_name = user_name;
            this.user_password = user_password;
        }
    }

编写mapper接口

public interface UserMapper { 
        //添加用户
        int addUser(User user);
        //修改用户信息
        int updateUserById(User user);
        //删除用户
        int deleteUserById(int id);
        //根据id查询用户
        User selectUserById(int id);
        //查询所有用户
        List<User> selectAllUser();
        //根据用户名模糊查询
        List<User> QueryUserByName(String username);
        //获取分页数据
        List<User> selectUserPage(Map<String,Object> map);
    }

编写接口对应的 Mapper.xml 文件

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="com.fly.mapper.UserMapper">
        <insert id="addUser" parameterType="user">
            insert into music.user (user_id,user_name,user_password)
            values (#{user_id},#{user_name},#{user_password})
        </insert>
        <update id="updateUserById" parameterType="user">
            update music.user set user_name=#{user_name},user_password=#{user_password} where user_id=#{user_id}
        </update>
        <delete id="deleteUserById" parameterType="int">
            delete from user where user_id=#{id}
        </delete>
        <select id="selectUserById" parameterType="int" resultType="user">
            select * from user where user_id=#{id}
        </select>
        <select id="selectAllUser" resultType="user">
            select * from music.user
        </select>
        <select id="QueryUserByName" resultType="user">
            select * from music.user where user_name LIKE "%"#{user_name}"%"
        </select>
        <select id="selectUserPage" parameterType="Map" resultType="user">
            select * from music.user
            <if test="user_name!=null">
                where user_name LIKE "%"#{user_name}"%"
            </if>
            <if test="start!=null and pagesize!=null">
                limit #{start},#{pagesize}
            </if>
        </select>
    </mapper>

编写service层接口和实现类

UserSercice 接口

public interface UserSercice { 
        //添加用户
        int addUser(User user);
        //修改用户信息
        int updateUserById(User user);
        //删除用户
        int deleteUserById(int id);
        //根据id查询用户
        User selectUserById(int id);
        //查询所有用户
        List<User> selectAllUser();
        //根据用户名模糊查询
        List<User> QueryUserByName(String username);
        //获取分页数据
        List<User> queryUserPage(int pageNo,int pageSize);
    }

UserSercice 的实现类

public class UserServiceImpl implements UserSercice { 
        private UserMapper userMapper;
    
        public void setUserMapper(UserMapper userMapper) { 
            this.userMapper = userMapper;
        }
    
        @Override
        public int addUser(User user) { 
            return userMapper.addUser(user);
        }
    
        @Override
        public int updateUserById(User user) { 
            return userMapper.updateUserById(user);
        }
    
        @Override
        public int deleteUserById(int id) { 
            return userMapper.deleteUserById(id);
        }
    
        @Override
        public User selectUserById(int id) { 
            return userMapper.selectUserById(id);
        }
    
        @Override
        public List<User> selectAllUser() { 
            return userMapper.selectAllUser();
        }
    
        @Override
        public List<User> QueryUserByName(String username) { 
    
            return userMapper.QueryUserByName(username);
        }
    
        @Override
        public List<User> queryUserPage(int pageNo, int pageSize) { 
            Map<String,Object> map=new HashMap<String,Object>();
            map.put("start",(pageNo-1)*pageSize);
            map.put("pagesize",pageSize);
            return userMapper.selectUserPage(map);
        }
    }

到这里底层需求已经完成了；接下来就是spring层了

spring层

1、配置Spring整合MyBatis，我们这里数据源使用c3p0连接池；spring-dao.xml配置

<?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" 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/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">
        
        
        <context:property-placeholder location="classpath:db.properties"/>
    
        
        
        <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            
            <property name="driverClass" value="${jdbc.drive}"/>
            <property name="jdbcUrl" value="${jdbc.url}"/>
            <property name="user" value="${jdbc.username}"/>
            <property name="password" value="${jdbc.password}"/>
            
            <property name="maxPoolSize" value="30"/>
            <property name="minPoolSize" value="10"/>
            
            <property name="autoCommitOnClose" value="false"/>
            
            <property name="checkoutTimeout" value="10000"/>
            
            <property name="acquireRetryAttempts" value="2"/>
        </bean>
        
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
            
            <property name="dataSource" ref="dataSource"/>
            
            <property name="configLocation" value="classpath:mybatis_config.xml"/>
        </bean>
        
        
        <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
            
            <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
            
            <property name="basePackage" value="com.fly.mapper"/>
        </bean>
    
        
        <tx:advice id="txAdvice" transaction-manager="transactionManager">
            <tx:attributes>
                
                <tx:method name="add" propagation="REQUIRED"/>
                <tx:method name="*" propagation="REQUIRED"/>
            </tx:attributes>
        </tx:advice>
        
        <aop:config>
            <aop:pointcut id="txPointcut" expression="execution(* com.fly.mapper.*.*(..))"/>
            <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointcut"/>
        </aop:config>
    </beans>

spring整合service层：spring-service.xml配置

SpringMVC层

web.xml配置

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0">
        
        <servlet>
            <servlet-name>DispatcherServlet</servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            <init-param>
                <param-name>contextConfigLocation</param-name>
                
                <param-value>classpath:applicationContext.xml</param-value>
            </init-param>
            <load-on-startup>1</load-on-startup>
        </servlet>
        <servlet-mapping>
            <servlet-name>DispatcherServlet</servlet-name>
            <url-pattern>/</url-pattern>
        </servlet-mapping>
        
        <filter>
            <filter-name>encodingFilter</filter-name>
            <filter-class>
                org.springframework.web.filter.CharacterEncodingFilter
            </filter-class>
            <init-param>
                <param-name>encoding</param-name>
                <param-value>utf-8</param-value>
            </init-param>
        </filter>
        <filter-mapping>
            <filter-name>encodingFilter</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>
    
        
        <session-config>
            <session-timeout>15</session-timeout>
        </session-config>
        
        <absolute-ordering />
    </web-app>

spring-mvc.xml

Spring配置整合文件，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"      xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
        <import resource="classpath:spring-dao.xml"/>
        <import resource="classpath:spring-service.xml"/>
        <import resource="classpath:spring-mvc.xml"/>
    </beans>

Controller 和 视图层编写

@Controller
    @RequestMapping("/user")
    public class UserController { 
        @Autowired
        @Qualifier("UserServiceImpl")
        private UserSercice userSercice;
    
        @RequestMapping("/allUser")
        public String ListUser(Model model){ 
            List<User> users=userSercice.selectAllUser();
            model.addAttribute("users",users);
            return "showPageUser";
        }
        @RequestMapping("/toAddUser")
        public String toAddUser() { 
            return "addUser";
        }
        @RequestMapping("/addUser")
        public String AddUser(User user){ 
            System.out.println(user);
            userSercice.addUser(user);
            return "redirect:/user/pageAllUser/0";
        }
        @RequestMapping("/toUpdateUser")
        public String toUpdateUser(Model model, int id) { 
            User user = userSercice.selectUserById(id);
            System.out.println(user);
            model.addAttribute("user",user );
            return "updateUser";
        }
    
        @RequestMapping("/updateUser")
        public String updateUser(Model model, User user) { 
            System.out.println(user);
            userSercice.updateUserById(user);
            User user1 = userSercice.selectUserById(user.getUser_id());
            model.addAttribute("user1", user1);
            return "redirect:/user/pageAllUser/0";
        }
    
        @RequestMapping("/deleteUser/{user_id}")
        public String deleteUser(@PathVariable("user_id") int id){ 
            userSercice.deleteUserById(id);
            return "redirect:/user/pageAllUser/0";
        }
    
        @RequestMapping("/queryUserByName")
        public String QueryUserByName(String user_name,Model model){ 
            System.out.println(user_name);
            List<User> userList= userSercice.QueryUserByName(user_name);
            System.out.println(userList);
            if (userList.size()==0){ 
                model.addAttribute("msg","不存在"+user_name+"的账户");
            }else { 
                model.addAttribute("users", userList);
            }
            return "showPageUser";
        }
    
        @RequestMapping("/pageAllUser/{pageNumber}")
        public String PageUser(Model model,@PathVariable("pageNumber") String pageNumber){ 
            String spPage=pageNumber;
            //设置每页条数
            int pageSize=10;
            //页数，对页数进行判断设置
            int pageNo=0;
            if (spPage==null){ 
                pageNo=1;
            }else { 
                pageNo=Integer.valueOf(spPage);
                if (pageNo<1){ 
                    pageNo=1;
                }
            }
            //设置首页
            int minPage=1;
            //设置最大页数
            List<User> userList=userSercice.selectAllUser();
            int totalCount=userList.size();    //获取总条数
            int maxPage=totalCount%pageSize==0?totalCount/pageSize:totalCount/pageSize+1;
            if (pageNo>maxPage){ 
                pageNo=maxPage;
            }
            try { 
                //分页查询
                List<User> users=userSercice.queryUserPage(pageNo,pageSize);
                //把信息放入model转发到页面
                model.addAttribute("users",users);
                model.addAttribute("pageNo",pageNo);
                model.addAttribute("totalCount",totalCount);
                model.addAttribute("maxPage",maxPage);
                model.addAttribute("minPage",minPage);
            } catch (Exception e) { 
                e.printStackTrace();
                return "error";
            }
            return "showPageUser";
        }
    }

index.jsp页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
      <head>
        <<title>首页</title>
        <style type="text/css"> a { text-decoration: none; color: black; font-size: 18px; } h3 { width: 180px; height: 38px; margin: 100px auto; text-align: center; line-height: 38px; background: deepskyblue; border-radius: 4px; } </style>
      </head>
      <body>
      <h3>
        <a href="${pageContext.request.contextPath}/user/pageAllUser/0">点击进入列表页</a>
      </h3>
      </body>
    </html>

人员信息分页展示页面：showPageUser.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>用户列表</title>
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        
        <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
    </head>
    <body>
    
    <div class="container">
        <div class="row clearfix">
            <div class="col-md-12 column">
                <div class="page-header">
                    <h1>
                        <small>用户列表 —— 显示所有用户</small>
                    </h1>
                </div>
            </div>
        </div>
        <div class="row">
            <div class="col-md-4 column">
                <a class="btn btn-primary" href="${pageContext.request.contextPath}/user/toAddUser">新增</a>
                <a class="btn btn-primary" href="${pageContext.request.contextPath}/user/pageAllUser/0">显示全部用户</a>
            </div>
            <div class="col-md-4 column"><span style="color: red;font-weight: bold">${msg}</span></div>
            <div class="col-md-4 column">
                <form method="post" class="form-inline" action="${pageContext.request.contextPath}/user/queryUserByName" style="float: right">
                        <input type="text" name="user_name" class="form-control" placeholder="请输入要查询的人员姓名"/>
                        <input type="submit" value="查询" class="btn btn-primary">
                </form>
            </div>
        </div>
        <div class="row clearfix">
            <div class="col-md-12 column">
                <table class="table table-hover table-striped">
                    <thead>
                    <tr>
                        <th>用户编号</th>
                        <th>用户名字</th>
                        <th>用户密码</th>
                        <th>注册日期</th>
                        <th>操作</th>
                    </tr>
                    </thead>
                    <tbody>
                    <c:forEach var="user" items="${requestScope.get('users')}">
                        <tr>
                            <td>${user.getUser_id()}</td>
                            <td>${user.getUser_name()}</td>
                            <td>${user.getUser_password()}</td>
                            <td>${user.getCreate_time()}</td>
                            <td>
                                <a href="${pageContext.request.contextPath}/user/toUpdateUser?id=${user.getUser_id()}">更改</a>
                                  |  
                                <a href="${pageContext.request.contextPath}/user/deleteUser/${user.getUser_id()}">删除</a>
                            </td>
                        </tr>
                    </c:forEach>
                    </tbody>
                    <tr align="center">
                        <td colspan="5">
                            <a href="${pageContext.request.contextPath}/user/pageAllUser/${minPage}">首页</a>
                            <a href="${pageContext.request.contextPath}/user/pageAllUser/${pageNo-1}">上一页</a>
                            <span>${pageNo} / ${maxPage}</span>
                            <a href="${pageContext.request.contextPath}/user/pageAllUser/${pageNo+1}">下一页</a>
                            <a href="${pageContext.request.contextPath}/user/pageAllUser/${maxPage}">尾页</a>
                        </td>
                    </tr>
                </table>
            </div>
        </div>
    </div>
    </body>
    </html>

添加用户页面：addUser.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <head>
            <title>新增用户</title>
            <meta name="viewport" content="width=device-width, initial-scale=1.0">
            
            <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
        </head>
    <body>
    <div class="container">
        <div class="row clearfix">
            <div class="col-md-12 column">
                <div class="page-header">
                    <h1>
                        <small>新增用户</small>
                    </h1>
                </div>
            </div>
        </div>
        <form action="${pageContext.request.contextPath}/user/addUser" method="post">
    
            <div class="form-group">
                <label>用户名字：</label>
                <input type="text" name="user_name" class="form-control"/>
            </div>
            <div class="form-group">
                <label>用户密码：</label>
                <input type="text" name="user_password" class="form-control"/>
            </div>
            <%--注册日期：<input type="text" name="create_time"><br><br><br>--%>
            <div class="form-group">
                <input type="submit" value="添加">
            </div>
        </form>
    </div>
    </body>
    </html>

用户信息修改页面：updateUser.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>修改信息</title>
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        
        <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
    </head>
    <body>
    <div class="container">
        <div class="row clearfix">
            <div class="col-md-12 column">
                <div class="page-header">
                    <h1>
                        <small>修改信息</small>
                    </h1>
                </div>
            </div>
        </div>
        <form action="${pageContext.request.contextPath}/user/updateUser" method="post">
    
            <input type="hidden" name="user_id" value="${user.user_id}"/>
            <div class="form-group">
                <label>用户名字：</label>
                <input type="text" name="user_name" class="form-control" value="${user.user_name}" required/>
            </div>
            <div class="form-group">
                <label>用户密码：</label>
            <input type="text" name="user_password" class="form-control" value="${user.user_password}"/>
            </div>
            <%--注册时间：<input type="text" name="create_time" value="${user.create_time}"/>--%>
            <div class="form-group">
                <input type="submit" value="修改"/>
            </div>
        </form>
    </div>
    </body>
    </html>

到这里一个SSM项目框架就已经搭建好了。  
后期规划，去JSP，使用ajax进行前后端交互，实现前后端分离  
路漫漫其修远兮，吾将上下而求索

[https_docs.spring.io_spring_docs_4.3.24.RELEASE_spring-framework-reference_html_mvc.html]: https://docs.spring.io/spring/docs/4.3.24.RELEASE/spring-framework-reference/html/mvc.html
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[SpringMVC]: /images/20221123/2b4150c99a494863a4214ca962599ea2.png
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[https_blog.csdn.net_qq_41510551_article_details_108756185]: https://blog.csdn.net/qq_41510551/article/details/108756185
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