1.pom依赖：

即：spring-boot的基本jar ---- 内置springmvc和spring

Thymeleaf jar

热部署 jar ---方便二次加载 ctrl+f9再次编译

Mybatis jar

Mysql jar

<dependency>

 	<groupId>org.springframework.boot</groupId>

     <artifactId>spring-boot-starter-web</artifactId>

</dependency>

<dependency>

     <groupId>org.springframework.boot</groupId>

     <artifactId>spring-boot-starter-thymeleaf</artifactId>

</dependency>

<dependency>

     <groupId>org.springframework.boot</groupId>

     <artifactId>spring-boot-starter-tomcat</artifactId>

</dependency>

<!--热部署-->

<dependency>

    <groupId>org.springframework.boot</groupId>

    <artifactId>spring-boot-devtools</artifactId>

    <optional>true</optional> <!-- 这个需要为 true 热部署才有效 -->

</dependency>

<!-- mybatis -->

<dependency>

    <groupId>org.mybatis.spring.boot</groupId>

    <artifactId>mybatis-spring-boot-starter</artifactId>

    <version>1.1.1</version>

</dependency>

<!-- mysql -->

<dependency>

    <groupId>mysql</groupId>

    <artifactId>mysql-connector-java</artifactId>

    <version>5.1.21</version>

</dependency>

2.application的配置：

#thymeleaf 配置

spring.thymeleaf.mode=HTML5

spring.thymeleaf.encoding=UTF-8

spring.thymeleaf.content-type=text/html

#缓存设置为false, 这样修改之后马上生效，便于调试

spring.thymeleaf.cache=false

#上下文

server.context-path=/thymeleaf

#视图层控制

#spring.mvc.view.prefix=classpath:/templates/

#spring.mvc.view.suffix=.html

#spring.mvc.static-path-pattern=/static/**

#数据库

spring.datasource.url=jdbc:mysql://127.0.0.1:3306/how2java?characterEncoding=UTF-8

spring.datasource.username=root

spring.datasource.password=

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

3.mapper层 以及非常简单的entity层：

@Mapper

@Repository

// 加上Repository注解，即可自动bean

public interface CategoryMapper {

    @Select("select * from category_ ")

    public List<Category> findAll();

}

4.service层 --- 以及serviceImpl实现层

@Service

public class CategoryServiceImpl implements CategoryService {

    @Autowired

    CategoryMapper;

    @Override

    public List<Category> selectAll() {

        return categoryMapper.findAll();

    }

}

5.controller层：

这个里面加了pagehelper，可以忽略

@Controller

public class CategoryController {

    @Autowired

    CategoryService categoryService;

    @RequestMapping("/listCategory")

    public String showList(Model model,

                           @RequestParam(value = "start", defaultValue = "0") int start,

                           @RequestParam(value = "size", defaultValue = "5") int size)

                            throws Exception{

        PageHelper.startPage(start,size);

        List<Category> list = categoryService.selectAll();

        PageInfo<Category> page = new PageInfo<>(list);

        model.addAttribute("page",page);

        return "listCategory";

    }

}

6.Thymeleaf --- 渲染模板：  有点类似于EL表达式的写法

<table border="1px">

    <tr>

        <th>id</th>

        <th>name</th>

    </tr>

    <tr th:each="l:${page.list}">

        <td th:text="${l.id}"></td>

        <td th:text="${l.name}"></td>

    </tr>

</table>

<a th:href="@{/listCategory(start=0)}">[首  页]</a>

<a th:href="@{/listCategory(start=${page.pageNum-1})}">[上一页]</a>

<a th:href="@{/listCategory(start=${page.pageNum+1})}">[下一页]</a>

<a th:href="@{/listCategory(start=${page.pages})}">[末  页]</a>