Sort out the power node, Mr. Wang he's SSM integration steps

1.SSM Integrate development steps

In general, it's SPringMVC Receive user requests -----Spring Medium Service object -----Mybatis Processing data

ssm Integration is also called ssi, There are containers in integration

1. First container SpringMVC Containers , management Controller Controller object .

2. The second container Spring Containers , management Service,dao, Utility class object

What we need to do is to give the used objects to the appropriate container to create , management . hold Controller also Web The relevant objects of development are handed over to Springmvc Containers ,

these web Unload with the object Springmvc（dispatcherServlet） In profile .

service,dao The object is defined in Spring In the configuration file , Give Way spring Manage the creation of these objects

3.springmvc The container is spring A child of a container , In a sub container Controller You can access... In the parent container Service object ,

Can be realized controller Use service object .

2. Implementation steps

1. Build a database , I use student A watch of （id,name,age）, Only name yes String type , The other two are Int.

2 Join the rely on

Springmvc,spring,mybatis The dependencies of the three frameworks ,jackson rely on ,mysql drive ,druid Connection pool ,jsp,servlet rely on

<?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 rely on -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <scope>provided</scope>
    </dependency>
    <!-- jsp rely on  -->
    <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><!-- directory -->
        <includes><!-- Including... In the directory .properties,.xml  All the files will be scanned -->
          <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. Write web.xml

(1) register DispatcherServlet, The goal is to create Spring Container object , Then you can create Controller Class object ; establish Servlet, To receive user requests .

（2） register spring Monitor ：ContextLoaderListener, The purpose is to create Spring Container object , To create service,dao Objects such as

（3） Register the character set filter , solve post Asking for garbled code .

<?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.-->
    <!-- Register the central scheduler -->
    <!--init-param Belong to a servlet all ;
       context-param Belongs to the entire application  ,
        Not just in servlet You can get ,jsp You can also get ,
        stay jsp in application It's equivalent to 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 It means that this... Is created when the server starts Servlet, Don't wait until you need to use it to create -->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
    <!--2-->
    <!-- establish Spring Monitor of container -->
    <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-->
    <!-- Register the character set filter -->
    <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>
        <!-- Set to /* when , It will cover everything else servlet, Include servlet All provided by the container servlet-->
    </filter-mapping>

</web-app>

4. Create a package ,Controller package ,service,dao, Entity class package name created

5.5. Write springmvc,spring,mybatis Configuration file for
 1）springmvc The configuration file

<?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 Configuration file for , Statement Controller And others Web Related objects -->
    <context:component-scan base-package="com.gaodeng.controller"/>

    <!-- view resolver -->
    <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.  Respond to ajax request , return json
    2.  Solve the problem of static resource access .
  -->
</beans>

 2）spring The configuration file

<?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">

    <!-- The information needed to connect to the database needs to be through <context:property-placeholder> Labels can only be used after importing -->
    <context:property-placeholder location="classpath:conf/jdbc.properties"/>
    <!-- Declare data source , Connect to database -->
    <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 establish SqlSessionFactory-->
    <bean id="SqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:conf/mybatis.xml"/>
    </bean>

    <!-- Statement MyBatis Scanner for , establish Dao Implementation class object of interface -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="SqlSessionFactory"/>
        <property name="basePackage" value="com.gaodeng.dao"/>
    </bean>

    <!-- Statement service Annotations @Service Package name and location -->
    <context:component-scan base-package="com.gaodeng.service"/>

    <!-- Transaction configuration ： Configuration of annotations , aspectj Configuration of -->
</beans>

 3）mybatis Master profile

<?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： control mybatis Global behavior -->
    <!-- <settings>
         &lt;!&ndash; Set up mybatis Output log &ndash;&gt;
         <setting name="logImpl" value="STDOUT_LOGGING"/>
     </settings>-->

    <!-- Set alias -->
    <typeAliases>
        <!--name: The package name of the entity class ( Package names that are not entity classes can also )-->
        <package name="com.gaodeng.domain"/>
    </typeAliases>


    <!-- sql mapper(sql The mapping file ) The location of -->
    <mappers>
        <!--
          name： It's the name of the bag ,  Everything in this bag mapper.xml It can be loaded at one time 
           Use package The requirements of ：
           1. mapper Document name and dao The interface name must be exactly the same , Include case 
           2. mapper Document and dao Interfaces must be in the same directory 
        -->
        <package name="com.gaodeng.dao"/>
    </mappers>
</configuration>

 4） Database property profile

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

6. Write code , dao Interface and mapper file , service And implementation classes ,controller, Entity class .

I mean, start with simple , First write the entity class , The attribute of the entity class should preferably be the same as the database field name , Prevent what is written later mybatis The mapping file deals with aliases .

Then write dao class ,service class . Last write controller class .

-------------------------------------------------------------------------- Structure diagram of package --------------------------------------------------------------------------------------------------------

 

Entity class

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 class

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 class

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 class

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 = " Add failure ";
        int num = service.addStudent(student);
        if(num>0){
            result = " Student ："+student.getName()+" Data added successfully ";
        }

        ModelAndView mv = new ModelAndView();
        mv.addObject("key1",result);
        // Specified jump jsp View page 
       mv.setViewName("show");
        return  mv;
    }
    @RequestMapping("/listStudent")
    @ResponseBody
    //
 public List<Student> listStudent(){
         List<Student> student = service.findStudent();
         return student;
    }
}

7. Write jsp page

index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String basePath = request.getScheme() + "://" +
            request.getServerName() + ":" + request.getServerPort() +
            request.getContextPath() + "/";
%>
<html>
<head>
    <title> Function entry </title>
    <base href="<%=basePath%>" />
</head>
<body>
<div align="center">
    <p>SSM A small chestnut integrated </p>
    <table>
        <tr>
            <td><a href="addStudent.jsp">  Registered students </a></td>
        </tr>
        <tr>
            <td><a href="listStudent.jsp"> Browse students </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> Registered students </title>
    <base href="<%=basePath%>" />
</head>
<body>
<div align="center">
    <form action="student/addStudent.do" method="post">
        <table>
            <tr>
                <td> full name ：</td>
                <td><input type="text" name="name"></td>
            </tr>
            <tr>
                <td> Age ：</td>
                <td><input type="text" name="age"></td>
            </tr>
            <tr>
                <td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td>
                <td><input type="submit" value=" register "></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> use ajax Search for student information </title>
    <base href="<%=basePath%>" />
    <script type="text/javascript" src="js/jquery-3.4.1.js"></script>
    <script type="text/javascript">
        $(function (){
            // On the current page dom After the object is loaded , perform loadStudentData（）
            loadStudentData();
            $("#btn1").click(function (){
                loadStudentData();
            })
        })
        function loadStudentData(){
            $.ajax({url:"student/listStudent.do",
              type:"get",
                dataType:"json",
                success:function (data){
                    // Clear old data 
                    $("#tbody").html("");
                    // Add new data 
                    $.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> Student number </tr>
        <tr> full name </tr>
        <tr> Age </tr>
        </thead>
        <tbody id = "tbody">

        </tbody>
    </table>
    <input type="button" id="btn1" value=" Query data ">
</div>
</body>
</html>

forward .jsp

<%--
  Created by IntelliJ IDEA.
  User:  Brother Deng called me 
  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> Results page </h1>
    <div> ${key1}</div>
</body>
</html>

Encountered bug, There are also some mistakes , Abnormal operation

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;

The exception is mybatis There is a problem in the configuration file , Check whether the label is correct , for example value and ref Need to distinguish .

Access static resources such as index.jsp When it comes to 404, The main reason is web.xml When creating a central scheduler in <url-pattern> The value of is written as "\", And there are no configuration related configurations .

The simplest is <url-pattern>*.xxx</url-pattern>.