springboot整合mybatis向页面返回数据

pom.xml文件

<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>4.0.0modelVersion>

  <groupId>com.java.springbootgroupId>
  <artifactId>springboot-demoartifactId>
  <version>1.0-SNAPSHOTversion>
  <packaging>warpackaging>

  <name>springboot-demo Maven Webappname>
  
  <url>http://www.example.comurl>

  <properties>
    <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
    <maven.compiler.source>1.7maven.compiler.source>
    <maven.compiler.target>1.7maven.compiler.target>
  properties>

  
  <parent>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-parentartifactId>
    <version>2.0.5.RELEASEversion>
  parent>

  <dependencies>

    <dependency>
      <groupId>org.springframework.bootgroupId>
      <artifactId>spring-boot-starterartifactId>
    dependency>
    
    
    <dependency>
      <groupId>org.springframework.bootgroupId>
      <artifactId>spring-boot-starter-webartifactId>
    dependency>

    
    <dependency>
      <groupId>org.springframework.bootgroupId>
      <artifactId>spring-boot-starter-thymeleafartifactId>
    dependency>

	
    <dependency>
      <groupId>mysqlgroupId>
      <artifactId>mysql-connector-javaartifactId>
    dependency>

    <dependency>
      <groupId>org.springframework.bootgroupId>
      <artifactId>spring-boot-starter-jdbcartifactId>
    dependency>

	
    <dependency>
      <groupId>org.mybatis.spring.bootgroupId>
      <artifactId>mybatis-spring-boot-starterartifactId>
      <version>1.3.0version>
    dependency>

  dependencies>
project>

application.yml配置文件

#设置访问端口
server:
  port: 8080

#设置数据库连接
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/student?useSSL=false
    driver-class-name: com.mysql.jdbc.Driver
    username: 用户名
    password: 密码
    initial-size: 10
    max-active: 20
    max-idle: 8
    min-idle: 8

  #设置静态资源访问
  resources:
    static-locations: classpath:static/
    
  #thymeleaf模板引擎
  thymeleaf:
    prefix: classpath:/templates/
    suffix: .html
    mode: HTML5
    encoding: UTF-8
    content-type: text/html
    cache: false

#mybatis配置
mybatis:
  mapper-locations: classpath:mapping/*.xml
  type-aliases-package: com.java.springboot.bean

#log日志
logging:
  level:
    com:
      example:
        mapper : debug

创建数据库表

自己存数据即可

CREATE TABLE `stus` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(50) DEFAULT NULL,
  `password` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=30 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

新建实体类（entity）

package com.java.springboot.entity;

public class User {

    private int id;

    private String username;

    private String password;

    public int getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

新建映射接口（mapper）

package com.java.springboot.mapper;

import com.java.springboot.bean.User;
import org.springframework.stereotype.Repository;

import java.util.List;

/** * @author Woo_home * @create by 2019/8/12 */
@Repository
public interface UserMapper {
	
	/* * 根据用户id查询用户 */
    User select(int id);

	/* *查询所有用户 */
    List<User> userList();
}

新建业务层（service）

和mapper一样即可

package com.java.springboot.service;

import com.java.springboot.entity.User;

public interface UserService {

    User findUserById(int id);

}

实现service接口

package com.java.springboot.server;

import com.java.springboot.bean.User;
import com.java.springboot.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/** * @author Woo_home * @create by 2019/8/12 */
@Service
public class UserService {

    @Autowired
    private UserMapper userMapper; //注入UserMapper

    public User select(int id){
        return userMapper.select(id);
    }

    public List<User> userList(){
        return userMapper.userList();
    }
}

UserMapper.xml

<mapper namespace="com.java.springboot.mapper.UserMapper">

    <select id="select" resultType="com.java.springboot.bean.User">
        select * from stus where id = #{id}
    select>

    <select id="userList" resultType="com.java.springboot.bean.User">
        select * from stus
    select>

mapper>

控制器（controller）

package com.java.springboot.controller;

import com.java.springboot.bean.User;
import com.java.springboot.server.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import java.util.List;

/** * @author Woo_home * @create by 2019/8/12 */
@Controller
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("/index")
    @ResponseBody
    public String index(){
        return "Hello Springboot";
    }

    @RequestMapping("select/{id}")
    @ResponseBody
    public String save(@PathVariable int id){
        return userService.select(id).toString();
    }

    @RequestMapping("/userList")
    public String userList(Model model){
        List<User> users = userService.userList();
        model.addAttribute("users",users);
        return "user";
    }
}

html代码

<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Titletitle>
    <link href="/css/bootstrap.css" rel="stylesheet">
head>

<body>

    <table class="table">
        <thead>
            <tr>
                <th>Idth>
                <th>Usernameth>
                <th>Passwordth>
            tr>
        thead>
        <tbody>
           <tr th:each="users:${users}">
               <td th:text="${users.id}">td>
               <td th:text="${users.username}">td>
               <td th:text="${users.password}">td>
           tr>
        tbody>
    table>

body>
html>

在浏览器输入
localhost:8080/index
localhost:8080/select/?
localhost:8080/userList
都可以访问到内容