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SpringMVC
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简介

SpringMVC概述

SpringMVC是Spring的子框架，是Spring为展现层提供的基于MVC设计理念优秀的web框架，是目前主流的MVC框架。
SpringMVC通过一套MVC注解，让POJO成为处理请求的控制器，而无须实现任何接口。

SpringMV处理请求的原理

  1. 客户端发起请求：用户通过浏览器或其他客户端向Spring MVC应用程序发送HTTP请求。

  2. 前端控制器接收请求：Spring MVC应用程序的入口点是前端控制器，通常是DispatcherServlet。前端控制器接收到所有的HTTP请求，并负责协调请求的处理。

  3. 处理器映射器（Handler Mapping）确定控制器：前端控制器使用处理器映射器来确定哪个控制器应该处理请求。处理器映射器会根据请求的URL或其他标识来选择适当的控制器。

  4. 处理器适配器（Handler Adapter）调用控制器方法：一旦前端控制器确定了要使用的控制器，它将委托给处理器适配器。处理器适配器负责调用控制器的处理方法，并传递请求的参数。控制器方法执行应用程序的业务逻辑，可能会调用服务、访问数据库或进行其他操作。

  5. 控制器方法返回模型和视图信息：控制器方法执行完后，它会返回一个模型（Model）对象，该模型包含了要呈现给用户的数据，以及一个逻辑视图名称。这个逻辑视图名称表示视图解析器应该使用哪个视图模板来呈现数据。

  6. 视图解析器解析视图名称：前端控制器将逻辑视图名称传递给视图解析器。视图解析器负责将逻辑视图名称解析为实际的视图模板路径。

  7. 视图呈现数据：视图根据模型的数据和视图模板生成HTML或其他响应内容，这将作为HTTP响应发送回客户端浏览器。

  8. 响应发送给客户端：前端控制器接收到视图生成的响应后，将其发送回客户端浏览器，用户可以在浏览器上看到呈现的页面。

搭建SpringMVC框架

导入jar

<dependencys>
    <!--spring web mvc-->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.3.29</version>
    </dependency>
<!--    thymeleaf与spring5整合包-->
    <dependency>
        <groupId>org.thymeleaf</groupId>
        <artifactId>thymeleaf-spring5</artifactId>
        <version>3.1.2.RELEASE</version>
    </dependency>
<!--    servlet-api-->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>4.0.1</version>
        <scope>provided</scope>
    </dependency>
</dependencys>

编写src/main/webapp/WEB-INF/web.xml配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/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>
<!--        设置springmvc配置文件路径-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
<!--        设置DispatcherServlet优先级，启动服务时创建servlet对象-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

创建springmvc.xml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 https://www.springframework.org/schema/context/spring-context.xsd">
<!--开启组件扫描-->
    <context:component-scan base-package="com.acaiblog"></context:component-scan>
<!--    配置视图解析器-->
    <bean id="viewResolver" class="org.thymeleaf.spring5.view.reactive.ThymeleafReactiveViewResolver">
<!-- 配置字符集属性-->
        <property name="characterEncoding" value="UTF-8"/>
<!--配置模版引擎属性-->
        <property name="templateEngine">
<!--            配置内部bean-->
            <bean class="org.thymeleaf.spring5.SpringTemplateEngine">
<!--                配置模块解析器属性-->
                <property name="templateResolver">
                    <bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">
<!--                        配置前缀-->
                        <property name="prefix" value="/WEB-INF/views"/>
                        <property name="suffix" value=".html"/>
<!--                        配置字符集-->
                        <property name="characterEncoding" value="UTF-8"/>
                    </bean>
                </property>
            </bean>
        </property>
    </bean>
</beans>

编写首页src/main/webapp/WEB-INF/pages/index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<a th:href="@{/HelloController}">发送请求</a>
</body>
</html>

@RequestMapping

为指定的类或方法设置url

注解位置

在类或类方法上面实现@RequestMapping注解

示例代码：

package com.acaiblog.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/EmpController")
public class EmpController {
    @RequestMapping("/saveEmp")
    public String saveEmp(){
        System.out.print("保存员工信息");
        return "success";
    }
}

注解属性

属性 类型 描述
value String 设置url
path String 与value属性一致
method RequestMethod 设置请求方法GET,POST,DELETE等
params String 为当前url设置请求参数
headers String 为当前url设置请求头信息

支持ANT风格路径

常用的通配符

  • ? 匹配一个字符
  • * 匹配多个字符
  • ** 匹配多层字符

@PathVariable

获取url中占位符的参数

注解位置

在参数的前面

示例代码

请求方法：

<a th:href="@{EmpController/testPathVariadb/1}"></a>

处理器方法：

package com.acaiblog.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/EmpController")
public class EmpController {
    @RequestMapping("/test/PathVariadb={id}")
    public String testPathVariadb(@PathVariable("id") Integer id){
        System.out.print(id);
        return "success";
    }
}

注解属性

属性 类型 描述
value String 设置占位符中的参数名
name String 与value属性的作用一致
required boolean 设置当前参数是否必须传递参数

RESTful CRUD

搭建环境

配置jar依赖

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.thymeleaf</groupId>
        <artifactId>thymeleaf-spring5</artifactId>
        <version>3.0.12.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>4.0.1</version>
        <scope>provided</scope>
    </dependency>
</dependencies>

创建src/main/webapp/WEB-INF/web.xml配置文件

<?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">
<!--    注册DispatcherServlet前端控制器-->
    <servlet>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!--        设置管理容器对象springmvc.xml配置文件路径-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
<!--       设置DispatcherServlet优先级启动服务器时创建Servlet对象-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

创建springmvc.xml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 https://www.springframework.org/schema/context/spring-context.xsd">
<!--开启组件扫描-->
    <context:component-scan base-package="com.acaiblog"></context:component-scan>
<!--    装配视图解析器-->
    <bean class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
        <property name="characterEncoding" value="UTF-8"/>
        <property name="templateEngine">
            <bean class="org.thymeleaf.spring5.SpringTemplateEngine">
                <property name="templateResolver">
                    <bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">
                        <property name="characterEncoding" value="UTF-8"/>
                        <property name="suffix" value=".html"/>
                        <property name="prefix" value="/WEB-INF/pages/"/>
                    </bean>
                </property>
            </bean>
        </property>
    </bean>
</beans>

创建src/main/webapp/WEB-INF/pages/index.html首页

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>首页</h2>
</body>
</html>

创建src/main/java/com/acaiblog/controller/ToIndexController.java

package com.acaiblog.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class ToIndexController {
    @RequestMapping("/")
    public String toIndexPage(){
        return "index";
    }
}
  • 添加web模块：IDE》File》Project Structure》Modules》Add》web》
  • 添加Artifacts：Add
  • 配置tomcat服务

查询增加用户

编辑src/main/webapp/WEB-INF/pages/index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>首页</h2>
<h3>添加员工</h3>
<form th:action="@{emp}" method="post">
    <input type="submit" value="添加员工">
</form>
<h3>通过id查询员工</h3>
<a th:href="@{emp/1001}">查询员工</a>
</body>
</html>

创建src/main/webapp/WEB-INF/pages/success.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>成功页面</title>
</head>
<body>
<h3>添加成功</h3>
</body>
</html>

创建src/main/java/com/acaiblog/controller/EmployeeController.java

package com.acaiblog.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class EmployeeController {
    private final static String SUCCESS = "success";
    @RequestMapping(value = "/emp",method = RequestMethod.POST)
    public String saveEmp(){
        System.out.print("添加员工");
        return SUCCESS;
    }
    @RequestMapping(value = "/emp/{id}", method = RequestMethod.GET)
    public String getEmpById(@PathVariable("id") Integer id){
        System.out.printf(String.format("获取员工信息ID: %d", id));
        return SUCCESS;
    }
}

修改和删除

编辑src/main/webapp/WEB-INF/web.xml注册过滤器

<?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">
    <filter>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>HiddenHttpMethodFilter</filter-name>
<!--        所有的请求都需要经过过滤器-->
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

编辑index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>首页</h2>
<h3>修改员工信息</h3>
<form th:action="@{/emp/1001}" method="post">
    <input type="hidden" name="_method" value="PUT">
    <input type="submit" value="修改员工信息">
</form>
<h3>删除员工信息</h3>
<form th:action="@{/emp/1001}" method="post">
    <input type="hidden" name="_method" value="DELETE">
    <input type="submit" value="删除员工信息">
</form>
</body>
</html>

编辑src/main/java/com/acaiblog/controller/EmployeeController.java新增修改和删除的方法

package com.acaiblog.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class EmployeeController {
    private final static String SUCCESS = "success";
    @RequestMapping(value = "/emp/{id}", method = RequestMethod.PUT)
    public String updateEmpById(@PathVariable("id") Integer id){
        System.out.printf(String.format("修改员工信息ID: %d",id));
        return SUCCESS;
    }
    @RequestMapping(value = "/emp/{id}", method = RequestMethod.DELETE)
    public String deleteEmpById(@PathVariable("id") Integer id){
        System.out.printf(String.format("删除员工信息ID: %d",id));
        return SUCCESS;
    }
}

SpringMVC处理请求数据

处理请求参数

自动入参

SpringMVC默认可以将请求参数名与入参参数名一致的参数自动入参。

示例代码

编辑index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>首页</h2>
<a th:href="@{/getRequestParam(empName='acai')}">获取请求参数</a>
</body>
</html>

编辑src/main/java/com/acaiblog/controller/requestParams.java

package com.acaiblog.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class requestParams {
    @RequestMapping(value = "/getRequestParam")
    public void getRequestParam( String empName){
        System.out.printf(String.format("员工名称: %s", empName));
    }
}

注解入参

当请求参数和入参名称不一致时，使用@RequestParam注解设置入参参数名。

@RequestParam属性

属性 类型 描述
value String 设置需要入参的参数名
name String 与value属性的作用一致
required Boolean 设置当前参数是否必须入参
defaultValue String 默认参数名

pojo入参

使用SpringMVC pojo入参,请求参数名和接受参数名要保持一致区分大小写。

示例代码

创建员工pojosrc/main/java/com/acaiblog/pojo/Employee.java

package com.acaiblog.pojo;

public class Employee {
    private Integer id;
    private String name;

    public Employee(Integer id, String name, String email, Double salary) {
        this.id = id;
        this.name = name;
        this.email = email;
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Employee{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", email='" + email + '\'' +
                ", salary=" + salary +
                '}';
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Double getSalary() {
        return salary;
    }

    public void setSalary(Double salary) {
        this.salary = salary;
    }

    private String email;
    private Double salary;
}

编辑index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org" xmlns="http://www.w3.org/1999/html">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>首页</h2>
<h3>处理请求参数</h3>
<form th:action="@{/saveEmp}" method="post">
    ID:<input type="text" name="id"></br>
    姓名:<input type="text" name="name"></br>
    邮箱:<input type="text" name="email"></br>
    工资:<input type="text" name="salary"></br>
    <input type="submit" value="创建员工">
</form>
</body>
</html>

编辑src/main/java/com/acaiblog/controller/requestParams.java创建saveEmp方法

package com.acaiblog.controller;

import com.acaiblog.pojo.Employee;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class requestParams {
    @RequestMapping(value = "/saveEmp", method = RequestMethod.POST)
    public String saveEmp(Employee employee){
        System.out.printf(String.format("员工信息: %s", employee));
        return "index";
    }
}

返回结果

员工信息: Employee{id=1001, name='acai', email='baocai.guo@qq.com', salary=18000.0}

处理请求头

每次发送请求时请求头包含了若干个属性，可以通@RequestHeander注解获取客户端信息，通过@RequestHeander即可将请求头的信息绑定到处理方法的入参中。

@RequestHeander属性

属性 类型 描述
value String 设置需要获取的请求头的名称
name String 作用与value一致
required Boolean 设置是否必须入参

示例代码

编辑index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org" xmlns="http://www.w3.org/1999/html">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>首页</h2>
<h3>处理请求头信息</h3>
<a th:href="@{/getHeander}">处理请求头数据</a>
</body>
</html>

编辑src/main/java/com/acaiblog/controller/requestParams.java创建getHander方法

package com.acaiblog.controller;

import com.acaiblog.pojo.Employee;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class requestParams {
    @RequestMapping(value = "/getHeander", method = RequestMethod.GET)
    public String getHander(@RequestHeader("Host") String hd){
        System.out.printf(String.format("请求头数据: %s",hd));
        return "index";
    }
}

处理Cookie

通过@CookieValue注解即可将请求头中的Cookie对象绑定到处理方法入参。

@CookieValue属性

属性 类型 描述
value String 设置需要获取的cookie的名称
name String 作用与value一致
required Boolean 设置是否必须入参

示例代码

编辑index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org" xmlns="http://www.w3.org/1999/html">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>首页</h2>
<a th:href="@{/setCookie}">设置cookie</a>
<a th:href="@{/getCookie}">获取cookie</a>
</body>
</html>

编辑src/main/java/com/acaiblog/controller/requestParams.java创建setCookie和getCookie方法

package com.acaiblog.controller;

import com.acaiblog.pojo.Employee;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CookieValue;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.http.HttpSession;

@Controller
public class requestParams {
    @RequestMapping(value = "/setCookie")
    public String setCookie(HttpSession session){
        System.out.printf(String.format("设置session id: %s",session.getId()));
        return "index";

    }
    @RequestMapping(value = "/getCookie")
    public String getCookie(@CookieValue("JSESSIONID") String session_id){
        System.out.printf(String.format("获取session id: %s", session_id));
        return "index";
    }
}

Servlet API处理请求数据

将原生Servelet相关对象入参即可

示例代码

编辑index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org" xmlns="http://www.w3.org/1999/html">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>首页</h2>
<a th:href="@{/getServlet}">使用request对象</a>
</body>
</html>

编辑src/main/java/com/acaiblog/controller/requestParams.java创建getServlet方法

package com.acaiblog.controller;

import com.acaiblog.pojo.Employee;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CookieValue;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

@Controller
public class requestParams {
    @RequestMapping(value = "/getServlet")
    public String getServlet(HttpServletRequest request){
        ServletContext servletContext = request.getServletContext();
        String realPath = servletContext.getRealPath("WEB-INF/pages/index.html");
        System.out.printf(String.format("文件路径: %s", realPath));
        return "index";

    }
}

SpringMVC处理响应数据

SpringMVC提供了以下两种途径输出模型数据：

  • ModelAndView：处理方法返回值为ModelAndView时，方法体即可通过该对象添加模型数据，最终会添加到request中。
  • Map或Mode或ModelMap：入参为java.util.map、org.springframwork.ui.Model或org.springframwork.ui.ModelMap时，处理方法返回时，Map中的数据会自动添加到模型中，最终添加到request中。

ModelAndView

示例代码：

@GetMapping("/testMvResponsedata")
public ModelAndView testMvResponsedata(){
    ModelAndView mv = new ModelAndView();
    //设置逻辑视图名
    mv.setViewName("response_success");
    //设置数据【将数据共享到域中（request\session\servletContext）】
    mv.addObject("stuName","zhouxu");
    return mv;
}

Model、ModelMap、Map

使用Model、ModelMap、Map作为方法入参，处理响应数据
示例代码：

/**
     * 使用Map、Model、ModelMap处理响应数据
     * @return
     */
    @GetMapping("/testMapResponsedata")
    public String testMapResponsedata(Map<String,Object> map
                                         /* Model model
                                        ModelMap modelMap*/){
        map.put("stuName","zhangsan");
//        model.addAttribute("stuName","lisi");
//        modelMap.addAttribute("stuName","wangwu");

        return "response_success";
    }

SpringMVC中域对象

SpringMVC封装数据，默认使用request域对象,session域的使用。
方式一：

/**
 * 测试响应数据【其他域对象】
 * @return
 */
@GetMapping("/testScopeResponsedata")
public String testScopeResponsedata(HttpSession session){
    session.setAttribute("stuName","xinlai");
    return "response_success";
}

方式二：

@Controller
@SessionAttributes(value = "stuName") //将request域中数据，同步到session域中
public class TestResponseData {
    /**
     * 使用ModelAndView处理响应数据
     * @return
     */
    @GetMapping("/testMvResponsedata")
    public ModelAndView testMvResponsedata(){
        ModelAndView mv = new ModelAndView();
        //设置逻辑视图名
        mv.setViewName("response_success");
        //设置数据【将数据共享到域中（request\session\servletContext）】
        mv.addObject("stuName","zhouxu");
        return mv;
    }
}

SpringMVC视图

视图解析器对象ViewResolver

  • 概述：ViewResolver接口的实现类或子接口，称之为视图解析器
  • 作用：将ModelAndView中的View对象解析出来

视图对象View

  • 概述：View接口的实现类或子接口，称之为视图对象
  • 作用：视图渲染将数据共享域中;跳转路径【转发或重定向】

视图控制器

视图控制器作用：为url映射html页面
编辑spring配置文件springmvc.xml

<!--    添加视图控制器-->
<mvc:view-controller path="/" view-name="index"/>
<mvc:view-controller path="/getServle" view-name="index"/>
<mvc:annotation-driven/>

加载静态资源

由DefaultServlet加载静态资源到服务器，比如：html、css、js等资源。
编辑tomcat/conf/web.xml

<servlet>
        <servlet-name>default</servlet-name>
        <servlet-class>org.apache.catalina.servlets.DefaultServlet</servlet-class>
        <init-param>
            <param-name>debug</param-name>
            <param-value>0</param-value>
        </init-param>
        <init-param>
            <param-name>listings</param-name>
            <param-value>false</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
<servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>/</url-pattern>
</servlet-mapping>

DispatcherServlet与DefaultServlet的URL配置均为：/，导致DispatcherServlet中的配置将DefaultServlet配置的/覆盖了【DefaultServlet失效，无法加载静态资源】,解决方案：

<!--    解决静态资源加载问题-->
<mvc:default-servlet-handler></mvc:default-servlet-handler>
<!-- 添加上述标签，会导致Controller无法正常使用，需要添加mvc:annotation-driven解决 -->
<mvc:annotation-driven></mvc:annotation-driven>

重定向

语法：return "redirect:/redirect.html";

编辑index.html页面

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org" xmlns="http://www.w3.org/1999/html">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>首页</h2>
<a th:href="@{/testDirect}">页面重定向</a>
</body>
</html>

编辑处理器方法

package com.acaiblog.controller;

import com.acaiblog.pojo.Employee;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

@Controller
public class requestParams {
    @GetMapping(value = "/testDirect")
    public String testDirect(){
        System.out.print("页面重定向");
        return "redirect:/redirect.html";
    }
}

编辑spring配置文件配置静态页面加载

<!--    静态资源加载-->
<mvc:default-servlet-handler/>

创建src/main/webapp/redirect.html页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>重定向页面</title>
</head>
<body>
<h3>重定向页面</h3>
</body>
</html>

SpringMVC处理数据

处理请求报文

获取请求报文有两种方式：@RequestBody注解和HttpEntity对象

RequestBody注解

编辑index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h2>请求体</h2>
<form th:action="@{/testRequestBody}" method="post">
    LastName: <input type="text" name="LastName"></br>
    Email: <input type="text" name="Email"></br>
    <input type="submit" value="提交">
</form>
</body>
</html>

编辑处理方法

package com.acaiblog.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class MessageConvertController {
    @RequestMapping(value = "/testRequestBody")
//    @RequestBody注解接受前端提交的表单数据
    public String testRequestBody(@RequestBody String request){
        System.out.printf(String.format("请求体数据: %s", request));
        return "index";
    }
}

HttpEntity对象

示例代码：

package com.acaiblog.controller;

import org.springframework.http.HttpEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class MessageConvertController {
    @RequestMapping(value = "/testRequestBody")
    public String testRequestBody(HttpEntity<String> request){
        System.out.printf(String.format("请求体数据: %s", request.getBody()));
        System.out.printf(String.format("请求头数据: %s", request.getHeaders()));
        return "index";
    }
}

处理响应报文

@ResponseBody注解的作用：将指定数据以直接响应的方式响应数据。比如：使用ResponseBody注解return返回的是数据，不使用ResponseBody注解返回的是页面。
示例代码：

package com.acaiblog.controller;

import org.springframework.http.HttpEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class MessageConvertController {
    @RequestMapping(value = "/testRequestBody")
    @ResponseBody
    public String testRequestBody(HttpEntity<String> request){
        System.out.printf(String.format("请求体数据: %s", request.getBody()));
        System.out.printf(String.format("请求头数据: %s", request.getHeaders()));
        return "hello world";
    }
}

SpringMVC消息处理器

消息转换器HttpMessageConverter主要作用：将java对象数据与请求或响应报文相互转换，例如：Java对象转json或json对象转java对象。
导入jar包

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.15.2</version>
</dependency>

装配MappingJackson2HttpMessageConverter消息转换器，在spring配置文件中添加

<mvc:annotation-driven/>

创建Emplyee pojo

package com.acaiblog.pojo;

public class Employee {
    private Integer id;
    private String name;

    public Employee(Integer id, String name, String email, Double salary) {
        this.id = id;
        this.name = name;
        this.email = email;
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Employee{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", email='" + email + '\'' +
                ", salary=" + salary +
                '}';
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Double getSalary() {
        return salary;
    }

    public void setSalary(Double salary) {
        this.salary = salary;
    }

    private String email;
    private Double salary;
}

使用处理器返回json数据,在方法上面使用@ResponseBody注解 

package com.acaiblog.controller;

import com.acaiblog.pojo.Employee;
import org.springframework.http.HttpEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class MessageConvertController {
    @RequestMapping(value = "/testRequestBody")
    @ResponseBody
    public Employee testRequestBody(HttpEntity<String> request){
        Employee employee = new Employee(1,"acai","acai@163.com",10000.00);
        return employee;
    }
}

后添加的jar包需要在ide》Project Structure》删除war重新添加，然后运行项目返回以下数据：

{"id":1,"name":"acai","email":"acai@163.com","salary":10000.0}

SpringMVC文件上传与下载

文件下载

创建下载文件src/main/webapp/WEB-INF/download/test.txt
编辑index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<a th:href="@{/fileDownload(filename='test.txt')}">文件下载</a>
</body>
</html>

配置下载文件处理器

package com.acaiblog.controller;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
@Controller
public class fileDownloadController {
    @RequestMapping(value = "/fileDownload")
    @ResponseBody
    public ResponseEntity<byte[]> fileDownload(HttpServletRequest request,
                                               String filename) throws IOException {
//        获取下载文件的真实路径
        String realPath = request.getServletContext().getRealPath("WEB-INF/download/"+filename);
//        创建输入流
        InputStream inputStream = new FileInputStream(realPath);
//        文件下载
        byte[] bytes = new byte[inputStream.available()];
//        读取文件
        inputStream.read(bytes);
//        设置响应头
        HttpHeaders httpHeaders = new HttpHeaders();
//        设置要下载文件的名字
        httpHeaders.add("Content-Dispostion","attachment;filename="+filename);
        httpHeaders.setContentDispositionFormData("attachment",new String(filename.getBytes("utf-8"),"ISO-8859-1"));
//        状态码
        ResponseEntity<byte[]> responseEntity = new ResponseEntity<>(bytes,httpHeaders, HttpStatus.OK);
        return responseEntity;
    }
}

文件上传

导入jar包

<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.5</version>
</dependency>

编辑index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org" xmlns="http://www.w3.org/1999/html">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<form th:action="@{/fileUploadController}" method="post" enctype="multipart/form-data">
    上传文件: <input type="file" name="uploadFile"></br>
    <input type="submit" value="提交">
</form>
</body>
</html>

装配CommonsMultipartResolver

<!--    装配CommonsMultipartResolver id必须是multipartResolver-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="defaultEncoding" value="UTF-8"/>
</bean>

编辑处理器方法

package com.acaiblog.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpSession;
import java.io.File;
import java.io.IOException;
import java.util.logging.Logger;

@Controller
public class FileUploadController {
    private static final Logger logger = Logger.getLogger(FileUploadController.class.getName());
    @RequestMapping(value = "/fileUplodController")
    public String fileUploadController(MultipartFile uploadFile,
                                       HttpSession session){
//        获取文件名
        String fileName = uploadFile.getOriginalFilename();

//        获取上传文件路径
        String realPath = session.getServletContext().getRealPath("/WEB-INF/upload");
        logger.info(String.format("realPath: %s", realPath));
//        判断上传路径是否存在，如果不存在则创建上传文件目录
        File filePath = new File(realPath);
        if(!filePath.exists()){
            filePath.mkdir();
        }
//        实现文件上传 File.pathSeparator路径分隔符比如：/
        File uFile = new File(filePath+File.separator+ fileName);
        logger.info(String.format("uFile: %s", uFile));
        try {
            uploadFile.transferTo(uFile);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return "index";
    }
}

优化文件上传

  • 允许同名文件上传
  • 设置文件上传大小限制

允许同名文件上传

//        创建uuid
String uuid = UUID.randomUUID().toString().replace("-", "");
//        实现文件上传 File.pathSeparator路径分隔符比如：/
File uFile = new File(filePath+File.separator+uuid+fileName);

设置文件上传大小限制

<!--    装配CommonsMultipartResolver id必须是multipartResolver-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="defaultEncoding" value="UTF-8"/>
<!--        设置上传文件大小限制为100kb-->
    <property name="maxUploadSizePerFile" value="102400"/>
</bean>

SpringMVC拦截器

拦截器与过滤器的区别

名称 描述 作用 执行时机
过滤器Filter 属于web服务器组件 过滤Servlet请求 Servlet前和Servlet后
拦截器Interceptor 属于SpringMVC框架 拦截Controller请求 执行Servlet之后，Controller之前；执行Controller之后，Servlet之前；执行DispatcherServlet之后

拦截器基本概念

SpringMVC可以使用拦截器对请求进行拦截处理，用户可以自定义拦截器来实现特定的功能。自定义的拦截器可以实现HandlerInterceptor接口，也可以继承HandlerInterceptorAdapter类。

HandlerInterceptor方法

方法名 描述
boolean preHandle() 在请求被处理之前调用，返回 true 表示继续处理，返回 false 表示中断处理。可用于身份验证、日志记录等操作。
void postHandle() 在请求处理之后但在视图渲染之前调用。可以用于修改 ModelAndView 或添加模型属性。
void afterCompletion() 在请求完成处理（包括视图渲染）之后调用。通常用于资源清理、记录日志等操作。

拦截器实现

实现拦截器

package com.acaiblog.Interceptor;

import org.springframework.lang.Nullable;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyInterceptor implements HandlerInterceptor {
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("执行controller之前");
        return true;
    }

    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {
        System.out.println("执行controller之后");
    }

    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {
        System.out.println("渲染视图之后");
    }

}

装配拦截器

<!--    装配拦截器-->
<mvc:interceptors>
    <bean class="com.acaiblog.Interceptor.MyInterceptor">
    </bean>
</mvc:interceptors>

局部配置拦截器

<!--    局部配置拦截器-->
<mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/fileUplodController"/>
        <bean class="com.acaiblog.Interceptor.MyInterceptor"/>
    </mvc:interceptor>
</mvc:interceptors>

拦截器的工作原理

单个拦截器工作原理

  • 浏览器向服务端发送请求
  • 执行拦截器preHandle方法
  • 执行controller方法，处理请求响应
  • 执行拦截器postHandle方法
  • 执行DispatcherServlet渲染视图
  • 执行拦截器afterCompletion方法
  • 响应数据返回给浏览器

多个拦截器工作原理

  • 浏览器向服务端发送请求
  • 执行拦截器1preHandle方法
  • 执行拦截器2preHandle方法
  • 执行controller方法，处理请求响应
  • 执行拦截器2postHandle方法
  • 执行拦截器1postHandle方法
  • 执行DispatcherServlet渲染视图
  • 执行拦截器2afterCompletion方法
  • 执行拦截器1afterCompletion方法
  • 响应数据返回给浏览器

注意：拦截器执行顺序由装配拦截器顺序决定。

SpringMVC异常处理器

为什么需要处理异常

如果程序执行时出现异常为处理，会导致程序终止不会继续往下执行。

SpringMVC中的异常处理器

SpringMVC通过HandlerExceptionResolve处理程序的异常，包括Handler映射，数据绑定以及目标方法执行时发生的异常。常用异常处理器类：DefaultHandlerExceptionResolve、SimpleMappingExceptionResolve

自定义异常处理器

装配异常处理器

<!--    装配异常处理器-->
    <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
        <property name="exceptionMappings">
            <props>
<!--                key是捕获到的异常类，error是需要跳转到页面比如：error.html-->
                <prop key="java.lang.ArithmeticException">error</prop>
            </props>
        </property>
    </bean>

SSM框架整合

spring整合springmvc步骤

创建ssm工程，导入jar包

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.thymeleaf</groupId>
        <artifactId>thymeleaf-spring5</artifactId>
        <version>3.0.12.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>4.0.1</version>
        <scope>provided</scope>
    </dependency>
</dependencies>

创建src/main/webapp/WEB-INF/web.xml配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
         http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
<!--    1. 注册CharacterEncodingFilter，解决请求乱码。-->
    <filter>
        <filter-name>CharacterEncodingFilter</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>
        <init-param>
            <param-name>forceRequestEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
<!--    2. 注册HiddenHttpMethodFilter，支持PUT、DELETE提交。-->
    <filter>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
<!--    3. 注册DispatcherServlet前端控制器，管理SpringMVC容器对象。-->
    <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:springmvc.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>
<!--    4. 注册一个上下文参数contextConfigLocation，设置spring.xml配置文件路径。-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring.xml</param-value>
    </context-param>
<!--    5. 注册ContextLoaderListener，管理spring容器对象。-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
</web-app>

创建src/main/resources/spring.xml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 https://www.springframework.org/schema/context/spring-context.xsd">
    <!--    开启组件扫描，排除controller层-->
    <context:component-scan base-package="com.acaiblog">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
</beans>

创建src/main/resources/springmvc.xml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"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!--    1. 开启组件扫描，只扫描controller层。-->
    <context:component-scan base-package="com.acaiblog">
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
<!--    2. 装配视图解析器。-->
    <bean class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
        <property name="characterEncoding" value="UTF-8"/>
        <property name="templateEngine">
            <bean class="org.thymeleaf.spring5.SpringTemplateEngine">
                <property name="templateResolver">
                    <bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">
                        <property name="characterEncoding" value="UTF-8"/>
                        <property name="prefix" value="/WEB-INF/pages"/>
                        <property name="suffix" value=".html"/>
                    </bean>
                </property>
            </bean>
        </property>
    </bean>
<!--    3. 装配视图控制器，view-controller。-->
    <mvc:view-controller path="/" view-name="index"/>
<!--    4. 装配default-servlet-handler，解决静态资源加载问题。-->
    <mvc:default-servlet-handler/>
<!--    5. 装配annotation-driven，解决view-controller、default-servlet-handler、jackson转配消息等问题。-->
    <mvc:annotation-driven/>
</beans>

创建src/main/webapp/WEB-INF/pages/index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h3>首页</h3>
</body>
</html>

IDE配置tomcat测试是否可以正常访问

Spring整合Mybatis

导入jar包

<dependencys>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>5.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>5.3.1</version>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.10</version>
    </dependency>
    <dependency>
        <groupId>org.mariadb.jdbc</groupId>
        <artifactId>mariadb-java-client</artifactId>
        <version>3.2.0</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.13</version>
    </dependency>
    <dependency>
        <groupId>com.github.pagehelper</groupId>
        <artifactId>pagehelper</artifactId>
        <version>5.1.8</version>
    </dependency>
</dependencys>

创建src/main/resources/db.properties配置文件

db.driverClassname=org.mariadb.jdbc.Driver
db.url=jdbc:mariadb://localhost:3306/ssm
db.username=root
db.password=123456

编辑src/main/resources/spring.xml配置文件

<beans>
    <!--    加载外部属性文件-->
    <context:property-placeholder location="db.properties"/>
    <!--    配置数据源-->
    <bean id="datasource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${db.driverClassname}"/>
        <property name="url" value="${db.url}"/>
        <property name="username" value="${db.username}"/>
        <property name="password" value="${db.password}"/>
    </bean>
    <!--    装配事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="datasource"/>
    </bean>
    <!--    开启声明式事务管理注解支持-->
    <tx:annotation-driven transaction-manager="transactionManager"/>
    <!--    装配SqlSessionFactoryBean，管理SqlSessionFactory-->
    <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="datasource"/>
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="typeAliaes" value="com.acaiblog.pojo"/>
        <property name="mapperLocations" value="classpath:/mapper/*.xml"/>
    </bean>
    <!--    装配MapperScannerConfigure，管理Mapper代理对象-->
    <mybatis-spring:scan base-package="com.acaiblog.mapper"/>
</beans>

创建src/main/resources/mybatis-config.xml配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
<!--        开启自动驼峰式命名映射-->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
<!--        开启延迟加载-->
        <setting name="lazyLoadingEnable" value="true"/>
<!--        设置加载数据按需加载-->
        <setting name="aggressiveLazyLoading" value="true"/>
<!--        开启二级缓存-->
        <setting name="cacheEnabled" value="true"/>
    </settings>
<!--    分页插件-->
    <plugins>
        <plugin interceptor="com.github.pagehelper.PageInterceptor"></plugin>
    </plugins>
</configuration>

创建src/main/java/com/acaiblog/controller/Employee.java

package com.acaiblog.controller;

public class Employee {
    private Integer id;
    private String last_name;
    private String email;
    private Integer salary;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getLast_name() {
        return last_name;
    }

    public void setLast_name(String last_name) {
        this.last_name = last_name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Integer getSalary() {
        return salary;
    }

    public void setSalary(Integer salary) {
        this.salary = salary;
    }

    public Employee(Integer id, String last_name, String email, Integer salary) {
        this.id = id;
        this.last_name = last_name;
        this.email = email;
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Employee{" +
                "id=" + id +
                ", last_name='" + last_name + '\'' +
                ", email='" + email + '\'' +
                ", salary=" + salary +
                '}';
    }
}

创建src/main/java/com/acaiblog/mapper/EmployeeMapper.java

package com.acaiblog.mapper;

import com.acaiblog.controller.Employee;

import java.util.List;

public interface EmployeeMapper {
    public List<Employee> selectAllEmps();
}

创建src/main/resources/mapper/EmployeeMapper.xml

<?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.acaiblog.mapper.EmployeeMapper">
    <select id="selectAllEmps" resultMap="employee">
        select id,last_name,email,salary from employee
    </select>
</mapper>

创建src/main/java/com/acaiblog/service/EmployeeService.java

package com.acaiblog.service;

import com.acaiblog.controller.Employee;

import java.util.List;

public interface EmployeeService {
    /*
    * 查询所有员工信息
    * */
    public List<Employee> getEmployees();
}

创建src/main/java/com/acaiblog/service/Impl/EmployeeServiceImpl.java

package com.acaiblog.service.Impl;

import com.acaiblog.controller.Employee;
import com.acaiblog.mapper.EmployeeMapper;
import com.acaiblog.service.EmployeeService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service("EmployeeService")
public class EmployeeServiceImpl implements EmployeeService {
    @Autowired
    private EmployeeMapper employeeMapper;
    public List<Employee> getEmployees(){
        return employeeMapper.selectAllEmps()  ;
    }
}

创建src/main/java/com/acaiblog/controller/EmployeeController.java

package com.acaiblog.controller;

import com.acaiblog.pojo.Employee;
import com.acaiblog.service.EmployeeService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

import java.util.List;
import java.util.Map;
import java.util.Objects;

@Controller
public class EmployeeController {
    @Autowired
    @Qualifier("EmployeeService")
    private EmployeeService employeeService;
    @GetMapping("/emps")
    public String getAllEmps(Map<String, Objects> map){
        List<Employee> employees = employeeService.getEmployees();
        map.put("emps",employees);
        return "index";
    }
}
文章作者: 慕容峻才
文章链接: https://www.acaiblog.top/SpringMVC/
版权声明: 本博客所有文章除特别声明外，均采用 CC BY-NC-SA 4.0 许可协议。转载请注明来自 阿才的博客！
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