springboot的各种配置

1.AOP配置

    <!--    AOP的依赖    --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-aop</artifactId></dependency>

package com.qf.HomeWork.aop;import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.Signature;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;/*** 该切面用于统计方法执行的时长*/
@Aspect
@Component
@Slf4j
public class TimeAspect {//1.定义切点@Pointcut("execution(* com.qf.HomeWork.controller.UserController.*(..))")public void timepointcut(){};//2.定义通知@Around("timepointcut()")public Object calculateTime(ProceedingJoinPoint pjp) throws Throwable {long start =System.currentTimeMillis();Object proceed = pjp.proceed();//获取当前调用的目标方法Signature signature = pjp.getSignature();long end =System.currentTimeMillis();log.info("{}请求消耗的时长为:{}ms",signature,(end-start));return proceed;}
}

2.Filter过滤器

先写一个过滤器的类 若用原生态Filter或者servlet 必须在 主启动类上面加@ServletComponentScan注解

package com.qf.HomeWork.filter;import com.qf.HomeWork.entity.Info;
import com.qf.HomeWork.mapper.InfoMapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
@Slf4j
@Component
public class InfoFilter implements Filter {@Autowiredprivate InfoMapper infoMapper;@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {log.info("============经过了InfoFilter过滤器================");HttpServletRequest req= (HttpServletRequest) request;long start = System.currentTimeMillis();log.info("起始时间戳:{}",start);String url = req.getRequestURI().toString();log.info("请求的url={}",url);String ip = req.getRemoteAddr();log.info("请求的ip={}",ip);String method = req.getMethod();log.info("请求的方式={}",method);chain.doFilter(request,response);long end = System.currentTimeMillis();Long time = end - start;log.info("请求所用时间为{}ms",time);infoMapper.add(new Info(null,url,ip,method,time.toString()));log.info("============离开了InfoFilter过滤器================");}}

然后在配置类里，注册此过滤器，然后就能在 请求的时候经过过滤器

package com.qf.HomeWork.config;import com.qf.HomeWork.filter.CheckPasswordFilter;
import com.qf.HomeWork.filter.CheckUserNameFilter;
import com.qf.HomeWork.filter.InfoFilter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;@Configuration
public class FilterConfig {@Autowiredprivate  InfoFilter infoFilter;//将InfoFilter对象放入注册器中，将注册器放入IOC容器中，让springboot拿到，然后调用选取有效的过滤器的执行链，遍历执行其方法。@Beanpublic FilterRegistrationBean<InfoFilter> infoFilterFilterRegistrationBean(){FilterRegistrationBean<InfoFilter> registrationBean = new FilterRegistrationBean<>();//要注册的filter的对象registrationBean.setFilter(infoFilter);//处理filter的url路径registrationBean.addUrlPatterns("/*");//设置优先级 越小优先级越高registrationBean.setOrder(Integer.MIN_VALUE);//   把注册器这个类的对象注入IOC容器里供Spring自行调用return registrationBean;}@Beanpublic FilterRegistrationBean<CheckUserNameFilter> checkUsernameFilterFilterRegistrationBean(){FilterRegistrationBean<CheckUserNameFilter> registrationBean = new FilterRegistrationBean<>();//要注册的filter的对象registrationBean.setFilter(new CheckUserNameFilter());//处理filter的url路径registrationBean.addUrlPatterns("/h1","/login/dologin");registrationBean.setOrder(2);return registrationBean;}@Beanpublic FilterRegistrationBean<CheckPasswordFilter> checkPasswordFilterFilterRegistrationBean(){FilterRegistrationBean<CheckPasswordFilter> registrationBean = new FilterRegistrationBean<>();//要注册的filter的对象registrationBean.setFilter(new CheckPasswordFilter());//处理filter的url路径registrationBean.addUrlPatterns("/h1","/login/dologin");registrationBean.setOrder(3);return registrationBean;}}

3.Interceptor拦截器

写一个拦截器的类

package com.qf.HomeWork.interceptor;import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;@Component
public class MyInterceptor implements HandlerInterceptor {@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {System.out.println("==========MyInterceptor preHandle==============");//放行该请求return true;}@Overridepublic void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {System.out.println("==========MyInterceptor postHandle==============");}@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {System.out.println("==========MyInterceptor afterCompletion==============");}
}

注册拦截器

package com.qf.HomeWork.config;import com.qf.HomeWork.interceptor.MyInterceptor;
import com.qf.HomeWork.interceptor.MyInterceptor2;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;@Configuration
public class InterceptorConfig implements WebMvcConfigurer {@AutowiredMyInterceptor myInterceptor;@AutowiredMyInterceptor2 myInterceptor2;@Overridepublic void addInterceptors(InterceptorRegistry registry) {//添加拦截器registry.addInterceptor(myInterceptor)//拦截路径.addPathPatterns("/login/dologin")//优先级.order(10);registry.addInterceptor(myInterceptor2).addPathPatterns("/login/dologin").order(1);}}

4.文件上传

spring: 
#图片上传大小 肯定存在 MultipartProperties这个类servlet:multipart:#单个文件最大大小max-file-size: 10MB#全部文件总大小max-request-size: 50MB
qf:      fileupload:path: F:\pathpng\      

package com.qf.HomeWork.controller;import com.qf.HomeWork.util.ResultVo;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;import javax.validation.Valid;
import java.io.File;
import java.io.IOException;
import java.util.UUID;@RestController
@RequestMapping("/up")
@Slf4j
public class UploadController {@Value("${qf.fileupload.path}")private String picdir;@RequestMapping("/pic")public ResultVo upload(MultipartFile photo) throws IOException {log.info("接收到文件为:{}",photo.getOriginalFilename());String extName = photo.getOriginalFilename().substring(photo.getOriginalFilename().lastIndexOf("."));String picPath=picdir;String filepath=picPath+ UUID.randomUUID().toString().replace("-","")+extName;log.info("上传路径为:{}",filepath);//存放文件photo.transferTo(new File(filepath));return ResultVo.ok(1,photo.getName());}}

5.文件下载

package com.qf.HomeWork.controller;import lombok.extern.slf4j.Slf4j;
import org.apache.tomcat.util.http.fileupload.IOUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import javax.servlet.http.HttpServletResponse;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;@RestController
@RequestMapping("/down")
@Slf4j
public class DownLoadController {@Value("${qf.fileupload.path}")private  String filedir;@RequestMapping("/pic")public  void  download(String picname, HttpServletResponse resp) throws IOException {//1.获取文件名对应文件的路径String filepath=filedir+picname;resp.addHeader("Content-Disposition","attachment;filename="+picname);log.info("文件路径:{}",filepath);//2. 将要下载的文件的字节数据拷贝到response对象的输出流中即可，不写响应头就和验证码响应浏览器原理相同IOUtils.copy(new FileInputStream(filepath), resp.getOutputStream());}}

6.验证码

先导依赖

<!--   验证码启动器     --><dependency><groupId>com.baomidou</groupId><artifactId>kaptcha-spring-boot-starter</artifactId><version>1.1.0</version></dependency>

yml

#验证码的配置
kaptcha:height: 50width: 200content:length: 2source: abcdefghjklmnopqrstuvwxyz23456789space: 2font:color: blackname: Arialsize: 40background-color:from: lightGrayto: whiteborder:enabled: truecolor: blackthickness: 1
#自定义验证码超时时间
qf:kapchar:timeout: 60

测试

package com.qf.HomeWork.controller;import com.baomidou.kaptcha.Kaptcha;
import com.baomidou.kaptcha.exception.KaptchaTimeoutException;
import com.qf.HomeWork.util.ResultVo;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;@RestController
@RequestMapping("/login")
@Slf4j
public class KapcherController {@Autowiredprivate Kaptcha kaptcha;@Value("${qf.kapchar.timeout}")private Integer timeout;@GetMapping("/kapchar")public void kapchar(){kaptcha.render();}@GetMapping("/validate")public ResultVo validate(@RequestParam("code") String code){log.info("入参为:code={}",code);try {boolean flag = kaptcha.validate(code,10);log.info("验证码校验结果,flag={}",flag);return ResultVo.ok(1,flag);}catch (Exception e){e.printStackTrace();return ResultVo.error(-1,false);}}@PostMapping("/dologin")public ResultVo dologin(@RequestParam("username") String username,@RequestParam("password")String password,@RequestParam("captcha")String captcha) {log.info("入参为:username={},password={},captcha={}", username, password, captcha);//校验验证码try {log.info("验证码有效时间为:timeout={}",timeout);boolean flag = kaptcha.validate(captcha,timeout);log.info("验证码校验结果,flag={}", flag);}catch (KaptchaTimeoutException e) {e.printStackTrace();return ResultVo.error(-1, "验证码超时");}catch (Exception e) {e.printStackTrace();return ResultVo.error(-1, "验证码错误");}//判断用户名密码是否正确if (username.equals("luffy") && password.equals("123456")) {return ResultVo.ok(1, "登录成功");} else {return ResultVo.error(-1, "登陆失败");}}
}

7.基于注解的校验功能

启用方法 在springboot2.7之前，都不用导入依赖， 依赖在我的博客上。升级版本就去导。

package com.qf.HomeWork.controller;import com.qf.HomeWork.entity.HelloVo;
import com.qf.HomeWork.entity.User;
import com.qf.HomeWork.util.ResultVo;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import javax.validation.Valid;
import javax.validation.constraints.*;@RestController
@RequestMapping("/p")
@Validated //开启基于注解的校验功能
public class PramcheckController {
//@Size(min=3,max=5,message = "长度应该在3-5之间")/***@NotNull注解要求name只是不能为null,可以为空串*/@RequestMapping("/test1")public ResultVo test1( @NotNull String name){System.out.println(name);return ResultVo.ok(1,name);}/***@NotEmpty注解要求name既不能为空串，也不能为null*/@RequestMapping("/test2")public ResultVo test2( @NotEmpty String name){System.out.println(name);return ResultVo.ok(1,name);}/***@Email 邮箱验证*/@RequestMapping("/test3")public ResultVo test3( @Email(message = "不合法邮箱") String name){System.out.println(name);return ResultVo.ok(1,name);}/***@Pattern 正则表达式验证*/@RequestMapping("/test4")public ResultVo test4( @Pattern(message = "你的手机号输入不对",regexp = "^1(3[0-9]|4[579]|5[0-35-9]|6[2567]|7[0-8]|8[0-9]|9[89])\\d{8}$") String name){System.out.println(name);return ResultVo.ok(1,name);}/***@Valid 验证对象的注解*/@RequestMapping("/test5")public ResultVo test5(@Valid HelloVo user){System.out.println(user);return ResultVo.ok(1,user);}
}

在实体类里面可以，加注解校验，然后在方法上加 @Valid 就可以开启校验了

package com.qf.HomeWork.entity;import lombok.Data;import javax.validation.constraints.Email;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;@Data
public class HelloVo {@NotNullprivate Integer id;//    @NotNull  // 需要该参数不能为null@NotEmpty   // 不可以为空串@Size(min = 5,max = 100)private String name;@Emailprivate String email;
}

8.启动类运行后面加上方法的操作

package com.qf.HomeWork.runner;import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;@Component
public class MyRunner implements ApplicationRunner {@Value("${server.port}")private Integer port;@Overridepublic void run(ApplicationArguments args) throws Exception {System.out.println("http://localhost:"+port);}
}

9.Swagger

导入依赖

<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId><version>2.2.9.RELEASE</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-configuration-processor</artifactId><version>2.2.9.RELEASE</version><optional>true</optional></dependency><!--     swagger依赖 ，两个 ，一个核心功能，一个UI可视化 --><dependency><groupId>io.springfox</groupId><artifactId>springfox-swagger2</artifactId><version>2.9.2</version></dependency><dependency><groupId>io.springfox</groupId><artifactId>springfox-swagger-ui</artifactId><version>2.9.2</version></dependency><!-- https://mvnrepository.com/artifact/com.github.xiaoymin/knife4j-spring-boot-starter  小刀启动器 --><dependency><groupId>com.github.xiaoymin</groupId><artifactId>knife4j-spring-boot-starter</artifactId><version>2.0.4</version></dependency>
</dependencies>

在主启动类上面加上

@EnableSwagger2//开启swagger依赖
@EnableKnife4j//开启knife4j皮肤

然后写个配置类

package com.qianfeng.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;/*** Swagger基础配置类* 此类相当于配置文件, 项目启动就立即自动加载此类**/
@Configuration
public class SwaggerConfiguration {@Beanpublic Docket buildDocket() {return new Docket(DocumentationType.SWAGGER_2).apiInfo(buildApiInfo()).select()// 要扫描的API(Controller)基础包.apis(RequestHandlerSelectors.basePackage("com.qianfeng.controller")).build();}private ApiInfo buildApiInfo() {Contact contact = new Contact("千锋教育","http://www.baidu.com","[e-mail]");return new ApiInfoBuilder().title("千峰教育API文档").description("平台管理服务api").contact(contact).version("1.0.0").build();}
}

加到IOC容器，即可使用

调用官网 小刀 http://localhost:8080/doc.html

​ swagger 访问地址：http://localhost:8080/swagger-ui.html

然后我把它写成了启动器

9.1Properties类

package com.qf.swagger.spring.boot.autoconfigure.properties;import org.springframework.boot.context.properties.ConfigurationProperties;@ConfigurationProperties("com.qf.swagger")
public class SwaggerProperties {//联系人的名字private String contactName;//联系人的网址private String contactUrl;//联系人的邮箱private String email;//文档的标题private String title;//项目的描述信息private String description;//项目的版本号private String version;//swagger扫描下的包private String packageName;public String getContactName() {return contactName;}public void setContactName(String contactName) {this.contactName = contactName;}public String getContactUrl() {return contactUrl;}public void setContactUrl(String contactUrl) {this.contactUrl = contactUrl;}public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public String getDescription() {return description;}public void setDescription(String description) {this.description = description;}public String getVersion() {return version;}public void setVersion(String version) {this.version = version;}public String getPackageName() {return packageName;}public void setPackageName(String packageName) {this.packageName = packageName;}
}

9.2 配置类

package com.qf.swagger.spring.boot.autoconfigure;import com.github.xiaoymin.knife4j.spring.annotations.EnableKnife4j;
import com.qf.swagger.spring.boot.autoconfigure.properties.SwaggerProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;@Configuration
@EnableSwagger2//开启swagger依赖
@EnableKnife4j//开启knife4j皮肤
@EnableConfigurationProperties(SwaggerProperties.class)
public class SwaggerAutoConfigure {@Autowiredprivate SwaggerProperties swaggerProperties;@Beanpublic Docket docket(){return new Docket(DocumentationType.SWAGGER_2).apiInfo(buildApiInfo()).select()// 要扫描的API(Controller)基础包.apis(RequestHandlerSelectors.basePackage(swaggerProperties.getPackageName())).build();}private ApiInfo buildApiInfo() {Contact contact = new Contact(swaggerProperties.getContactName(),swaggerProperties.getContactUrl(),swaggerProperties.getEmail());return new ApiInfoBuilder().title(swaggerProperties.getTitle()).description(swaggerProperties.getDescription()).contact(contact).version(swaggerProperties.getVersion()).build();//最后调用build方法返回ApiInfo对象}}

9.3 yml文件配置+导入依赖即可使用

com:qf:swagger:package-name: com.qf.HomeWork.controllercontact-name: 蒋铭基contact-url: http://www.baidu.comemail: [e-mail]: 蒋铭基的接口API文档description: 这是蒋铭基项目的接口描述文档的描述信息。很棒！version: 1.1.0

<dependency><groupId>com.qf</groupId><artifactId>swagger-spring-boot-start</artifactId><version>1.0-SNAPSHOT</version>
</dependency>

10.druid 配置

导入依赖

<!-- 德鲁伊启动器     -->
<dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.6</version>
</dependency>
<!-- Mysql    --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.47</version></dependency>

yml配置数据源

#配置数据源
spring:datasource:driver-class-name: com.mysql.jdbc.Driverusername: rootpassword: 2001url: jdbc:mysql://localhost:3306/test?useSSL=true&useUnicode=true&characterEncoding=utf8type: com.alibaba.druid.pool.DruidDataSource

即可调用数据源 ，已经在IOC容器里面了 也可也使用JDBC模板,但是必须要导入 spring-boot-starter-jdbc依赖

package com.qf;import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;@SpringBootTest
class Spring05DataApplicationTests {//数据源会自动装配,配置类数据源类型,会通过XXXproperties绑定的XXXAutoConfigure里的Bean加载到IOC容器里面，// 当包生效，就会把数据源放入到IOC容器里。@Autowiredprivate DataSource dataSource;@Testvoid contextLoads() throws SQLException {System.out.println(dataSource.getClass());//获取数据源链接Connection connection = dataSource.getConnection();System.out.println(connection);connection.close();}}

11.全局异常类

package com.qf.HomeWork.exhandler;import com.qf.HomeWork.util.ResultVo;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;@RestControllerAdvice//全局异常处理器的注解，相当于增强通知
public class GlobalExHandler {
//底层不是AOP，就是调用了DispatcherServlet,拿到映射器处理器找到对应的Controller,应该是捕获到异常的时候，就会触发映射器找到这个方法，实现这个方法响应，一个数据给客户端@ExceptionHandler(Exception.class)public ResultVo handleEx(Exception e){e.printStackTrace();return ResultVo.error(-1,"出异常了，请与运维联系!");}}

12.静态资源处理

@Configuration
public class WebConfig implements WebMvcConfigurer {@Overridepublic void addResourceHandlers(ResourceHandlerRegistry registry) {// 这种方式也会覆盖掉默认的web静态资源目录registry.addResourceHandler("/**").addResourceLocations("classpath:static/","classpath:templates/");}
}

# 注意：这样配置会覆盖掉默认的web静态资源目录
spring.web.resources.static-locations=classpath:/templates

13.日期格式配置

#日期格式jsonjackson:date-format: yyyy-MM-dd HH:mm:sstime-zone: GMT+8

package com.qf.HomeWork.entity;import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.format.annotation.DateTimeFormat;import java.util.Date;@NoArgsConstructor
@AllArgsConstructor
@Data
public class Student {private Integer id;private String name;private String sex;private Integer age;//跟json，没关系，一般是表单提交查询字符串的时候，用这个，@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")//因为刚刚不是用springboot去接受的，用的是jackson来接收的，所以得加上这个注解，//请求有过滤器，响应有响应头，纯文本响应头，json响应头。//请求日期类型有 dateTimeFormat  json有 JsonFormat 在 springboot配置文件已经配好了，在自动装配里会把配置信息放入Jackson对象，放到IOC容器里//springboot这个底层也是用jackson接收，他在配置文件里写了，被注入IOC容器得jackson对象配置了注入日期格式的问题。
//    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss",timezone = "GMT+8")//会用就行，记住大概的原理，一查就知道了，不需要记得那么牢，就是格林威治时间与中国时区差8小时private Date birthday;private Integer status;
}

14.springboot整合Mybatis

<!--        mysql驱动-->
<dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId>
</dependency><!--        druid连接-->
<dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.1.10</version>
</dependency><!--        mybatis-->
<dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>1.3.2</version>
</dependency>

导入依赖

#mybatis 的必要配置，配置mapperxml文件的位置 类路径包括导入所有jar包的类路径下的所有文件夹下的所有Mapper.xml为映射文件。
mybatis:mapper-locations: classpath*:**/*Mapper.xml
#开启mybatis的sql日志。
logging:level:com.qf.HomeWork.mapper: debug

配置文件

15.SpringBoot整合分页助手

<!--        pageHelper依赖-->
<dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper-spring-boot-starter</artifactId><version>1.2.5</version>
</dependency>

@Test
public void test(){SqlSession sqlSession = MyBatisUtils.getSqlSession();BookMapper mapper = sqlSession.getMapper(BookMapper.class);//分页PageHelper.startPage(2,5);List<Book> byPage = mapper.findByPage();//分页对象，里面有各种上一页，下一页，总页数，什么的数据PageInfo<Book> pageInfo = new PageInfo<>(byPage);for (Book book : byPage) {System.out.println(book);}System.out.println("---------------");System.out.println(pageInfo);System.out.println(pageInfo.getList());}

16.springboot整合Mybatis-plus

导入依赖

     <!-- 基于 mybatis plus 的dao层的相关依赖 start--><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.5.2</version></dependency><!-- 德鲁伊启动器     --><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.6</version></dependency><!--    数据库依赖--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.47</version></dependency><!-- 基于 mybatis plus 的dao层的相关依赖 end-->

#开启mybatis-plus的sql日志。
logging:level:com.qf.HomeWork.mapper: debug

通过继承BaseMapper<泛型> 来继承自动SQL的生成

package com.qf.MP2302.mapper;import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.qf.MP2302.entity.Category;import java.util.List;public interface CategoryMapper extends BaseMapper<Category> {List<Category> findAll(int parentID);}

17.springboot整合事务

@Transactional(rollbackFor = Exception.class,isolation = Isolation.READ_COMMITTED)//隔离级别，调整为读已提交

在方法上加上这个就能代理这个方法，或者加到类上，就能让类里所有的方法开启事务。

18.springboot整合生成SQL原理，实体类字段配置

//定义在实体类里/*** mybatis-plus不允许下划线，他会有默认的命名策略，将驼峰命名映射到数据库的下划线的数据库名，绑定对应的值* 如果不用驼峰命名，下划线，虽然能查出来条数，也会生成正确的sql，但是数据回显的时候，他会将数据库查询出来的，字段* 映射成驼峰命名的map集合，但是在实体类里，它却是下划线，所以匹配不到属性，赋不上值，所以，传回来一个空对象，，如果有值，就创建对象，没值，就把空对象加入集合里，没有映射上去的话，就是ORM，从下划线映射成驼峰命名，这个策略，若* 属性不是驼峰命名，则对应不上，就会返回一个空对象，把这个空对象加入集合，最后就会存在很多空对象的集合 ！！！* mybatis-plus加了@TableField(exist = false)，这个就会，表示这个属性不存在字段在数据库当中，也不会映射，上去，不会报错*/
@TableName("sys_user")//定义表名,加载类名上
@TableId(type = IdType.AUTO,value = "category_id")//定义主键，加载字段上
//INPUT 是自动填充NULL。然后数据库自增
//NONE是数字UUID，
//AUTO 主键自增  其他都懂
@TableField("category_name")//定义字段
@TableField(exist = false)//定义属性不在数据库字段里
@Version//乐观锁的版本号
@TableLogic//逻辑删除键  数据库表中的逻辑删除字段设置默认值为0（未删除）。

19.Mybatis-plus整合分页插件

@Configuration
// 在mybatisplus的配置类上也可以添加注解扫描，启动类和配置类二选一，添加一处即可
// @MapperScan("scan.your.mapper.package")
public class MybatisPlusConfig {/*** 新的分页插件,一缓和二缓遵循mybatis的规则,需要设置 MybatisConfiguration#useDeprecatedExecutor = false 避免缓存出现问题(该属性会在旧插件移除后一同移除)*/@Beanpublic MybatisPlusInterceptor mybatisPlusInterceptor() {MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));return interceptor;}}

@Test
void select() {Page<User> userPage = new Page<>(1,3);
//这里示范无条件查询，所以nulluserPage= userDao.selectPage(userPage,null);long total = userPage.getTotal();System.out.println("总条数:"+total);System.out.println("总页数:"+userPage.getPages());System.out.println("当前页数据:"+userPage.getRecords());
}

分页查询，用map集合接收,map集合当实体类,key就是Select后面的字段，包括别名

@Test
void selectByPage() {//ORM映射,这个问题解决了，就是SQL查出来的数据封装成Map集合Page<Map<String,Object>> userPage = new Page<>(1,3);userPage= userDao.selectMapsPage(userPage,null);long total = userPage.getTotal();System.out.println("总条数:"+total);System.out.println("总页数:"+userPage.getPages());System.out.println("当前页数据:"+userPage.getRecords());
}

20.乐观锁与springboot整合

在配置类：注册

@Bean
public MybatisPlusInterceptor mybatisPlusInterceptor() {MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();interceptor.addInnerInterceptor(new OptimisticLockerInnerInterceptor());return interceptor;
}

乐观锁的例子

package com.qf.MP2302.service.impl;import com.qf.MP2302.entity.Product;
import com.qf.MP2302.mapper.ProductMapper;
import com.qf.MP2302.service.ProductService;
import lombok.AllArgsConstructor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Transactional;
@Service
public class ProductServiceImpl implements ProductService {@Autowiredprivate ProductMapper productMapper;@Transactional(rollbackFor = Exception.class,isolation = Isolation.READ_COMMITTED)//隔离级别，调整为读已提交@Overridepublic boolean modPrice(Long id, Integer deltaPrice) {//1.根据id查询商品信息Product product = productMapper.selectById(id);Integer cunrrentPrice = product.getPrice();Integer newPrice = cunrrentPrice - deltaPrice;//2.修改数据库表product.setPrice(newPrice);int i = productMapper.updateById(product);//3.乐观锁的补偿机制，如果出现i=0的情况，说明出现了并发冲突，重试while (i==0){Product  productAgain=productMapper.selectById(id);Integer againPrice = productAgain.getPrice();int newPriceAgain = againPrice - deltaPrice;productAgain.setPrice(newPriceAgain);i=productMapper.updateById(productAgain);}return i==1;}
}

21.Mybatis-plus 代码自动生成器

导入依赖

   <dependencies><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.5.2</version></dependency><!--   mybatis-plus-generator  代码生成器   start  需要mysql依赖 --><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-generator</artifactId><version>3.5.2</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-freemarker</artifactId><version>2.2.9.RELEASE</version></dependency><!--   mybatis-plus-generator  代码生成器   end --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.47</version></dependency></dependencies>

通过主启动类，启动，来实现代码的自动生成

package com.qf.gen;import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.generator.FastAutoGenerator;
import com.baomidou.mybatisplus.generator.config.OutputFile;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;
import com.baomidou.mybatisplus.generator.fill.Column;import java.util.Arrays;
import java.util.Collections;
import java.util.List;public class Gen {public static void main(String[] args) {FastAutoGenerator.create("jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai&useSSL=false", "root", "2001")// 全局配置.globalConfig((scanner, builder) -> builder.author(scanner.apply("请输入作者名称？")).fileOverride().outputDir("F:/MPgen"))// 包配置.packageConfig((scanner, builder) -> builder.parent(scanner.apply("请输入包名？")).moduleName(scanner.apply("请输入模块名？")).pathInfo(Collections.singletonMap(OutputFile.xml, "F:/MPgen")))// 策略配置.strategyConfig((scanner, builder) -> builder.addInclude(getTables(scanner.apply("请输入表名，多个英文逗号分隔？所有输入 all"))).controllerBuilder().enableRestStyle().enableHyphenStyle().entityBuilder().enableLombok().addTableFills(new Column("create_time", FieldFill.INSERT)).build())/*模板引擎配置，默认 Velocity 可选模板引擎 Beetl 或 Freemarker.templateEngine(new BeetlTemplateEngine()).templateEngine(new FreemarkerTemplateEngine())*/.templateEngine(new FreemarkerTemplateEngine()).execute();}// 处理 all 情况protected static List<String> getTables(String tables) {return "all".equals(tables) ? Collections.emptyList() : Arrays.asList(tables.split(","));}
}

代码生成器使用流程

1. 搭建springboot+mp环境
2. 设计数据表
3. 搭建mp代码生成器工程，使用工程生成模块代码
4. 拷贝代码到指定目录
5. 移植其他项目各分层代码