首先https://start.spring.io/下载一个springBoot的demo。

然后增加pomyila依赖，引入以下pom，除了MybatisPlus其他自己分配

<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.shiyan.my</groupId>
    <artifactId>my</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.baomidou/mybatis-plus-boot-starter -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.6</version>
        </dependency>
        <!-- freemarker -->
        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
        </dependency>
        <!-- fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.15</version>
        </dependency>
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>4.1.4</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.2.2</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.2.2</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
        <finalName>demo</finalName>
    </build>


</project>

application.properties配置文件如下：具体参数自己配置

server.servlet.context-path=/sys
#mysql
spring.datasource.url=jdbc:mysql://localhost:3306/user?useUnicode=true&characterEncoding=utf8
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

mybatis-plus.mapper-locations=classpath:/mapper/*.xml
mybatis-plus.type-aliases-package=com.shiyan.demo.beans

mybatis-plus.global-config.id-type=0
mybatis-plus.global-config.db-column-underline=true
mybatis-plus.global-config.capital-mode=true

logging.level.com.shiyan.demo.mapper=debug

代码生成器部分代码，不完善

    public void testGenerator() {
        // 全局配置
        GlobalConfig config = new GlobalConfig();
        config.setActiveRecord(true) // 是否支持AR模式
                .setAuthor("ais") // 作者
                .setOutputDir("E:\\xuexi\\demo\\src\\main\\java")
                // 生成路径
                .setFileOverride(true)// 文件覆盖
                .setServiceName("%sService").setBaseColumnList(true).setBaseResultMap(true) // 设置生成的service接口名
                /* 首字母是否为I */
                .setIdType(IdType.AUTO); // 主键策略//数据源配置
        DataSourceConfig dsConfig = new DataSourceConfig();
        dsConfig.setDbType(DbType.MYSQL).setUrl("jdbc:mysql://localhost:3306/user")
                .setDriverName("com.mysql.jdbc.Driver").setUsername("root").setPassword("root");
        // 策略配置
        StrategyConfig stConfig = new StrategyConfig();
        stConfig.setCapitalMode(true) // 全局大写命名
                //.setDbColumnUnderline(true) // 表名 字段名 是否使用下滑线命名
                .setNaming(NamingStrategy.underline_to_camel) // 数据库表映射到实体的命名策略
                .setInclude("tbl_employee") // 生成的表
                .setTablePrefix("tbl_"); // 表前缀
        // 包名策略
        PackageConfig pkConfig = new PackageConfig();
        pkConfig.setParent("com.shiyan.demo").setController("controller").setEntity("beans").setService("service");
        AutoGenerator ag = new AutoGenerator().setGlobalConfig(config).setDataSource(dsConfig).setStrategy(stConfig)
                .setPackageInfo(pkConfig);
        ag.execute();
    }

重点：MybatisPlusConfig的配置主要是加载一些插件注入bean

@Configuration
@EnableTransactionManagement
@MapperScan("com.shiyan.demo.mapper*") 
//扫描dao或者是Mapper接口
public class MybatisPlusConfig {
    
    
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor page = new PaginationInterceptor();
        page.setDialectType("mysql");
        
        return page;
    }

    @Bean
    public PerformanceInterceptor performanceInterceptor() {
        PerformanceInterceptor page = new PerformanceInterceptor();
        page.setFormat(true);
        return page;
    }
    
    //配置mybatis的分页插件pageHelper
    @Bean
    public PageHelper pageHelper(){
        PageHelper pageHelper = new PageHelper();
        Properties properties = new Properties();
        properties.setProperty("offsetAsPageNum","true");
        properties.setProperty("rowBoundsWithCount","true");
        properties.setProperty("reasonable","true");
        properties.setProperty("dialect","mysql");    //配置mysql数据库的方言
        pageHelper.setProperties(properties);
        return pageHelper;
    }
}

SwaggerConfig的配置文件如下

@Configuration
@EnableSwagger2
public class SwaggerConfig {

    @Bean
    public Docket createRestApi() throws IOException {
        return new Docket(DocumentationType.SWAGGER_2).apiInfo(apiInfo()).select().apis(RequestHandlerSelectors.basePackage("com.shiyan.demo")).paths(PathSelectors.any()).build();
    }

    private ApiInfo apiInfo() throws IOException {
        return new ApiInfoBuilder().title("誓言--------").termsOfServiceUrl("http://data.***.com/").contact("***").version("0.0.1").build();
    }
}

EmployeeController 分页的有两个，一个是MybatisPlus自己封装的一个是PageHelper。

MybatisPlus分页插件：单表操作可以用selectPage，下面是测试代码，个人推荐用MybatisPlus的分页，强大，简洁

image

@Api("测试")
@RestController
public class EmployeeController {

    @Resource
    private EmployeeService employeeService;

    @ApiOperation(value = "获取所有用户")
    @PostMapping("/queryAll")
    public List<Employee> queryEmployees() {
        List<Employee> selectList = employeeService.list();

        return selectList;
    }

    @ApiOperation(value = "新增用户")
    @PostMapping("/insert")
    public Integer insert(@RequestBody Employee employee) {
        Employee employee2 = new Employee();
        employee2.setAge(employee.getAge());
        employee2.setGender(employee.getGender());
        employee2.setLastName(employee.getLastName());
        employee2.setEmail(employee.getEmail());
        employeeService.save(employee2);
        return employee2.getId();
    }

    @ApiOperation(value = "修改用户")
    @PostMapping("/update")
    public boolean update(@RequestBody Employee employee) {
        Employee employee2 = new Employee();
        employee2.setAge(employee.getAge());
        employee2.setGender(employee.getGender());
        employee2.setLastName(employee.getLastName());
        employee2.setEmail(employee.getEmail());
        employee2.setId(employee.getId());
        boolean update = employeeService.update(employee2, null);
        return update;
    }

    @ApiOperation(value = "删除用户")
    @PostMapping("/delete")
    public boolean delete(@RequestBody Integer id) {

        boolean update = employeeService.removeById(id);
        return update;
    }

    @ApiOperation(value = "根据ID获取用户")
    @PostMapping("/getByid")
    public Employee getByid(@RequestBody Integer id) {

        Employee byid = employeeService.getByid(id);
        return byid;
    }

    @ApiOperation(value = "所有")
    @PostMapping("/getAll")
    public IPage<Employee> getAllssss(@RequestBody PageInput input) {

        Page<Employee> page = new Page<>(input.getPageNum(), input.getPageSize());
        IPage<Employee> all = employeeService.getAll(page);
        return all;
    }

    @ApiOperation(value = "所有2")
    @PostMapping("/getAll2")
    public List<Employee> getAllssss2(@RequestBody PageInput input) {

        PageHelper.startPage(input.getPageNum(), input.getPageSize());
        List<Employee> all = employeeService.getAll2();
        Long all2 = employeeService.getAll();
        PageBean<Employee> pageData = new PageBean<>(input.getPageNum(), input.getPageSize(), all2.intValue());
        pageData.setItems(all);
        List<Employee> items = pageData.getItems();
        return items;
    }

看下结果：

image