[Java知识库]整理动力节点王鹤老师ssm整合步骤

1.SSM整合开发步骤

总体来说就是 SPringMVC接收用户请求-----Spring中的Service对象-----Mybatis处理数据

ssm整合也叫做ssi，整合中有容器

1.第一容器SpringMVC容器，管理Controller控制器对象。

2.第二个容器Spring容器，管理Service,dao,工具类对象

我们要做的就是把使用的对象交给合适的容器创建，管理。把Controller还有Web开发的相关对象交给Springmvc容器，

这些web用的对象卸载Springmvc（dispatcherServlet）配置文件中。

service，dao对象定义在Spring的配置文件中，让spring管理创建这些对象

3.springmvc容器是spring容器的子容器，在子容器中的Controller可以访问父容器中的Service对象，

就可以实现controller使用service对象。

2.实现步骤

1.建立一个数据库，本人使用的是student的一张表（id,name,age），只有name是String类型，其他两个是Int。

2加入依赖

Springmvc，spring,mybatis三个框架的依赖，jackson依赖，mysql驱动，druid连接池，jsp，servlet依赖

<?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>com.gaodeng</groupId>
  <artifactId>ssm-gao</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>


  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <!--servlet依赖-->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <scope>provided</scope>
    </dependency>
    <!-- jsp依赖 -->
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.2.1-b03</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.9.0</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.9.0</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.3.1</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.1</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.9</version>
    </dependency>
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.1.12</version>
    </dependency>
  </dependencies>

  <build>
    <resources>
      <resource>
        <directory>src/main/java</directory><!--所在的目录-->
        <includes><!--包括目录下的.properties,.xml 文件都会扫描到-->
          <include>**/*.properties</include>
          <include>**/*.xml</include>
        </includes>
        <filtering>false</filtering>
      </resource>
    </resources>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

3.写web.xml

(1)注册DispatcherServlet，目的是创建Spring容器对象，之后才能创建Controller类对象；创建Servlet，才能接收用户的请求。

（2）注册spring监听器：ContextLoaderListener，目的是在服务器启动时创建Spring容器对象，才能创建service，dao等对象

（3）注册字符集过滤器，解决post请求乱码的问题。

<?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">


    <!--1.-->
    <!--注册中央调度器-->
    <!--init-param属于一个servlet所有；
       context-param属于整个应用程序所有 ,
       不仅是在servlet中可以得到,jsp文件中也可以得到，
       在jsp中application就相当于这里的servletContext. -->
    <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:conf/dispatcherServlet.xml</param-value>
        </init-param>
        <!--1表示在服务器启动的时候就创建该Servlet，不用等到需要使用再创建-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
    <!--2-->
    <!--创建Spring容器的监听器-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:conf/applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <!--3-->
    <!--注册字符集过滤器-->
    <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>
        <init-param>
            <param-name>forceResponseEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>characterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
        <!--设置为/*时，它会覆盖其他所有的servlet，包括servlet容器提供的所有servlet-->
    </filter-mapping>

</web-app>

4.创建包，Controller包，service，dao，实体类包名创建好

5.5.写springmvc，spring，mybatis的配置文件
?1）springmvc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">
  <!--Springmvc的配置文件，声明Controller和其他Web相关对象-->
    <context:component-scan base-package="com.gaodeng.controller"/>

    <!--视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/JSP/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
    <mvc:annotation-driven/>
    <!--
    1. 响应ajax请求，返回json
    2. 解决静态资源访问问题。
  -->
</beans>

?2）spring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">

    <!--连接数据库的需要的信息需要通过<context:property-placeholder>标签导入才能使用-->
    <context:property-placeholder location="classpath:conf/jdbc.properties"/>
    <!--声明数据源，连接数据库-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--SqlSessionFactoryBean创建SqlSessionFactory-->
    <bean id="SqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:conf/mybatis.xml"/>
    </bean>

    <!--声明MyBatis的扫描器，创建Dao接口的实现类对象-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="SqlSessionFactory"/>
        <property name="basePackage" value="com.gaodeng.dao"/>
    </bean>

    <!--声明service的注解@Service所在的包名位置-->
    <context:component-scan base-package="com.gaodeng.service"/>

    <!--事务配置：注解的配置， aspectj的配置-->
</beans>

?3）mybatis主配置文件

<?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：控制mybatis全局行为-->
    <!-- <settings>
         &lt;!&ndash;设置mybatis输出日志&ndash;&gt;
         <setting name="logImpl" value="STDOUT_LOGGING"/>
     </settings>-->

    <!--设置别名-->
    <typeAliases>
        <!--name:实体类所在的包名(不是实体类的包名也可以)-->
        <package name="com.gaodeng.domain"/>
    </typeAliases>


    <!-- sql mapper(sql映射文件)的位置-->
    <mappers>
        <!--
          name：是包名， 这个包中的所有mapper.xml一次都能加载
          使用package的要求：
           1. mapper文件名称和dao接口名必须完全一样，包括大小写
           2. mapper文件和dao接口必须在同一目录
        -->
        <package name="com.gaodeng.dao"/>
    </mappers>
</configuration>

?4）数据库的属性配置文件

jdbc.url=jdbc:mysql://localhost:3306/gaodeng
jdbc.username=root
jdbc.password=123456

6.写代码， dao接口和mapper文件， service和实现类，controller， 实体类。

按我的意思从简单的开始写，先写实体类，实体类的属性最好与数据库字段名相同，防止后面写的mybatis映射文件要处理别名。

然后就写dao类，service类。最后写controller类。

--------------------------------------------------------------------------包的结构图--------------------------------------------------------------------------------------------------------

?

实体类

package com.gaodeng.domain;

public class Student {
    private Integer id;
    private String name;
    private Integer age;

    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 Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public Student() {
    }

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

dao类

package com.gaodeng.dao;

import com.gaodeng.domain.Student;

import java.util.List;

public interface StudentDao {
    int insertStudent(Student student);
    List<Student> selectStudent();
}







<?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.gaodeng.dao.StudentDao">
    <select id="selectStudent" resultType="Student">
        select id,name,age from student order by id desc
    </select>

    <insert id="insertStudent">
        insert into student(name,age) values(#{name},#{age})
    </insert>
</mapper>

service类

package com.gaodeng.service;

import com.gaodeng.domain.Student;

import java.util.List;

public interface StudentService {
    int addStudent(Student student);
    List<Student> findStudent();
}






package com.gaodeng.service.impl;

import com.gaodeng.dao.StudentDao;
import com.gaodeng.domain.Student;
import com.gaodeng.service.StudentService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;


@Service
public class StudentServiceImpl implements StudentService {
    @Resource
    private StudentDao studentdao;

    @Override
    public int addStudent(Student student) {
        int i = studentdao.insertStudent(student);
        return i;
    }

    @Override
    public List<Student> findStudent() {
        return studentdao.selectStudent();
    }
}

controller类

package com.gaodeng.controller;

import com.gaodeng.domain.Student;
import com.gaodeng.service.StudentService;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;

import javax.annotation.Resource;
import java.util.List;


@Controller
@RequestMapping("/student")
public class StudentController {
    @Resource
    private StudentService service;

    @RequestMapping("/addStudent")
    public ModelAndView addStudent(Student student) {
        String result = "添加失败";
        int num = service.addStudent(student);
        if(num>0){
            result = "学生："+student.getName()+"添加数据成功";
        }

        ModelAndView mv = new ModelAndView();
        mv.addObject("key1",result);
        //指定跳转jsp视图页面
       mv.setViewName("show");
        return  mv;
    }
    @RequestMapping("/listStudent")
    @ResponseBody
    //
 public List<Student> listStudent(){
         List<Student> student = service.findStudent();
         return student;
    }
}

7.写jsp页面

index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String basePath = request.getScheme() + "://" +
            request.getServerName() + ":" + request.getServerPort() +
            request.getContextPath() + "/";
%>
<html>
<head>
    <title>功能入口</title>
    <base href="<%=basePath%>" />
</head>
<body>
<div align="center">
    <p>SSM整合的一个小小的栗子</p>
    <table>
        <tr>
            <td><a href="addStudent.jsp"> 注册学生</a></td>
        </tr>
        <tr>
            <td><a href="listStudent.jsp">浏览学生</a></td>
        </tr>
    </table>
</div>

</body>
</html>

addStudent.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String basePath = request.getScheme() + "://" +
            request.getServerName() + ":" + request.getServerPort() +
            request.getContextPath() + "/";
%>

<html>
<head>
    <title>注册学生</title>
    <base href="<%=basePath%>" />
</head>
<body>
<div align="center">
    <form action="student/addStudent.do" method="post">
        <table>
            <tr>
                <td>姓名：</td>
                <td><input type="text" name="name"></td>
            </tr>
            <tr>
                <td>年龄：</td>
                <td><input type="text" name="age"></td>
            </tr>
            <tr>
                <td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td>
                <td><input type="submit" value="注册"></td>
            </tr>
        </table>
    </form>
</div>
</body>
</html>

ListStudent.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String basePath = request.getScheme() + "://" +
            request.getServerName() + ":" + request.getServerPort() +
            request.getContextPath() + "/";
%>

<html>
<head>
    <title>用ajax查询学生信息</title>
    <base href="<%=basePath%>" />
    <script type="text/javascript" src="js/jquery-3.4.1.js"></script>
    <script type="text/javascript">
        $(function (){
            //在当前页面dom对象加载后，执行loadStudentData（）
            loadStudentData();
            $("#btn1").click(function (){
                loadStudentData();
            })
        })
        function loadStudentData(){
            $.ajax({url:"student/listStudent.do",
              type:"get",
                dataType:"json",
                success:function (data){
                    //清除旧的数据
                    $("#tbody").html("");
                    //增加新的数据
                    $.each( data, function (i,n){
                        $("#tbody").append("<tr>")
                            .append("<td>"+n.id+"</td>")
                            .append("<td>"+n.name+"</td>")
                            .append("<td>"+n.age+"</td>")
                            .append("</tr>")
                    })
                }
            })
        }
    </script>
</head>
<body>
<div align="center">
    <table>
        <thead>
        <tr>学号</tr>
        <tr>姓名</tr>
        <tr>年龄</tr>
        </thead>
        <tbody id = "tbody">

        </tbody>
    </table>
    <input type="button" id="btn1" value="查询数据">
</div>
</body>
</html>

转发.jsp

<%--
  Created by IntelliJ IDEA.
  User: 登哥叫我
  Date: 2022/1/28
  Time: 21:35
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>

</head>
<body>
    <h1>结果页面</h1>
    <div> ${key1}</div>
</body>
</html>

碰到的bug，还有一些错误，运行异常

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'SqlSessionFactory' defined in class path resource [conf/applicationContext.xml]: Invocation of init method failed; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 30; columnNumber: 1;

该异常是mybatis配置文件中出现了问题，检擦标签是否正确，例如value 和ref需要区分开。

访问静态资源比如index.jsp时出现的404，主要原因是web.xml中的创建中央调度器的时候<url-pattern>的值写成了"\",且没有配置相关的一些配置。

最简单的就是<url-pattern>*.xxx</url-pattern>。