华南农业大学Linux课程综合实验——用Java语言，实现从MySQL读取内容并显示在浏览器上

前言

用Java语言实现从Linux的MySQL读取内容并显示在浏览器上

项目结构

项目代码

StudentController.java

package com.controller;

import com.pojo.Student;
import com.service.StudentService;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

/**
 * @Description: 把查询到的结果发送到 jsp
 * @param null 
 * @return null
 * @Author Squirrel_Lee
 * @CreateTime 2022/5/30 19:45
 */

@WebServlet("/studentServlet")
public class StudentController extends HttpServlet {
    private StudentService service=new StudentService();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        List<Student> student=service.selectStudents();
        req.setAttribute("student",student);
        req.getRequestDispatcher("/student.jsp").forward(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doPost(req, resp);
    }
}

StudentMapper.java

package com.mapper;

import com.pojo.Student;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.ResultMap;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * @Description:
 * @param null 
 * @return null
 * @Author Squirrel_Lee
 * @CreateTime 2022/5/30 19:45
 */

@Mapper
@Repository
public interface StudentMapper {
    @Select("select * from student")
    @ResultMap("studentResultMap")
    List<Student> selectStudents();
}

Student.java

package com.pojo;

/**
 * @Description: ·student实体类
 * @param null 
 * @return null
 * @Author Squirrel_Lee
 * @CreateTime 2022/5/30 19:45
 */

public class Student {
    private Integer id;
    private String studentId;
    private String studentName;

    public Integer getId() {
        return id;
    }

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

    public String getStudentId() {
        return studentId;
    }

    public void setStudentId(String studentId) {
        this.studentId = studentId;
    }

    public String getStudentName() {
        return studentName;
    }

    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }

    public Student(Integer id, String studentId, String studentName) {
        this.id = id;
        this.studentId = studentId;
        this.studentName = studentName;
    }

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

StudentService.java

package com.service;

import com.mapper.StudentMapper;
import com.pojo.Student;
import com.util.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @Description:
 * @param null 
 * @return null
 * @Author Squirrel_Lee
 * @CreateTime 2022/5/30 19:45
 */

@Service
public class StudentService {
    SqlSessionFactory factory= SqlSessionFactoryUtils.getSqlSessionFactory();
    public List<Student> selectStudents(){
        SqlSession sqlSession=factory.openSession();

        StudentMapper mapper=sqlSession.getMapper(StudentMapper.class);

        List<Student> student=mapper.selectStudents();

        sqlSession.close();

        return student;
    }
}

SqlSessionFactoryUtils.java

package com.util;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class SqlSessionFactoryUtils {

    private static SqlSessionFactory sqlSessionFactory;

    static {
        //静态代码块会随着类的加载而自动执行，且只执行一次

        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    public static SqlSessionFactory getSqlSessionFactory(){
        return sqlSessionFactory;
    }
}

CommunityServletInitializer.java

package com;

import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

public class CommunityServletInitializer extends SpringBootServletInitializer {

    //tomcat访问该方法作为入口来运行该项目
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(DemoApplication.class); //这里指出该项目的main方法所在的类
    }
}

DemoApplication.java

package com;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

@SpringBootApplication(exclude= DataSourceAutoConfiguration.class)
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(com.DemoApplication.class, args);
    }
}

StudentMapper.xml

DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.mapper.StudentMapper">



    <resultMap id="studentResultMap" type="student">
        <result column="student_id" property="studentId">result>
        <result column="student_name" property="studentName">result>
    resultMap>
mapper>

mybatis-config.xml

DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    
    <typeAliases>
        <package name="com.pojo"/>
    typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                
                <property name="url" value="jdbc:mysql://localhost:3306/linux_test?useSSL=false"/>
                 
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            dataSource>
        environment>
    environments>
    <mappers>
        
        <package name="com.mapper"/>
    mappers>
configuration>

student.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<c:forEach items="${student}" var="stu" varStatus="status">
    <td>${status.count}</td>
    <td>${stu.studentId}</td>
    <td>${stu.studentName}</td>
</c:forEach>
</body>
</html>

pom.xml

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.5.6version>
        <relativePath/> 
    parent>
    <groupId>com.examplegroupId>
    <artifactId>demoartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>demoname>
    <description>Demo project for Spring Bootdescription>

    <properties>
        <java.version>1.8java.version>
    properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>

        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
        dependency>
        <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
            <version>2.1.0version>
        dependency>
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>fastjsonartifactId>
            <version>1.2.58version>
        dependency>
        <dependency>
            <groupId>jstlgroupId>
            <artifactId>jstlartifactId>
            <version>1.2version>
        dependency>
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatisartifactId>
            <version>3.5.2version>
        dependency>

    dependencies>

    <packaging>warpackaging>
    <build>
        <finalName>ROOTfinalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
            plugin>
        plugins>
    build>

project>