使用ResponseBodyAdvice做分页处理

亦凉 2023-10-14 16:46 63阅读 0赞

**目录**

父pom文件

pom文件

配置文件

MyResponseBodyAdvice

ResponseDto

MyBatisConfig

UsersController

UsersMapper

UserMapper.xml

结果

--------------------

![aae30dfd75e8469db6b360e5e71a5aaf.png][]

## 父pom文件 ##

<?xml version="1.0" encoding="UTF-8"?>
    <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>4.0.0</modelVersion>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            
            <version>2.2.5.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.chensir</groupId>
        <artifactId>springboot</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>springboot</name>
        <description>springboot</description>
        <properties>
            <java.version>8</java.version>
            <hutool.version>5.8.3</hutool.version>
            <lombok.version>1.18.24</lombok.version>
            <alibaba-sdk.version>2.0.0</alibaba-sdk.version>
        </properties>
    
        <packaging>pom</packaging>
    
        <modules>
            <module>servlet</module>
            <module>spring-interceptor</module>
            <module>spring-aop</module>
            <module>spring-united-reslut</module>
            <module>spring-jdbc</module>
            <module>spring-mybatis</module>
        </modules>
    
        <dependencyManagement>
            <dependencies>
    
               
                <dependency>
                    <groupId>com.aliyun</groupId>
                    <artifactId>alibaba-dingtalk-service-sdk</artifactId>
                    <version>${alibaba-sdk.version}</version>
                </dependency>
    
                <dependency>
                    <groupId>cn.hutool</groupId>
                    <artifactId>hutool-all</artifactId>
                    <version>${hutool.version}</version>
                </dependency>
    
                <dependency>
                    <groupId>org.projectlombok</groupId>
                    <artifactId>lombok</artifactId>
                    <version>${lombok.version}</version>
                </dependency>
    
    
    
    
    
    
    
    
    
    
    
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

## pom文件 ##

<?xml version="1.0" encoding="UTF-8"?>
    <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>4.0.0</modelVersion>
        <parent>
            <groupId>com.chensir</groupId>
            <artifactId>springboot</artifactId>
            <version>0.0.1-SNAPSHOT</version>
            <relativePath>../pom.xml</relativePath>
        </parent>
    
        <artifactId>spring-mybatis</artifactId>
    
        <dependencies>
            <dependency>
                <groupId>com.github.pagehelper</groupId>
                <artifactId>pagehelper</artifactId>
                <version>5.1.10</version>
            </dependency>
    
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>2.1.4</version>
            </dependency>
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </dependency>
    
            <dependency>
                <groupId>cn.hutool</groupId>
                <artifactId>hutool-all</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                 <optional>true</optional>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter-test</artifactId>
                <version>2.1.4</version>
                <scope>test</scope>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <configuration>
                        <excludes>
                            <exclude>
                                <groupId>org.projectlombok</groupId>
                                <artifactId>lombok</artifactId>
                            </exclude>
                        </excludes>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    
    </project>

## 配置文件 ##

spring.datasource.url=jdbc:mysql://localhost/db1?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8&autoReconnect=true&rewriteBatchedStatements=true
    spring.datasource.username=root
    spring.datasource.password=root
    spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

## MyResponseBodyAdvice ##

package com.chensir.advice;
    
    import cn.hutool.core.lang.Dict;
    import cn.hutool.core.util.StrUtil;
    import cn.hutool.json.JSONUtil;
    import com.github.pagehelper.Page;
    import org.springframework.core.MethodParameter;
    import org.springframework.http.MediaType;
    import org.springframework.http.converter.StringHttpMessageConverter;
    import org.springframework.http.server.ServerHttpRequest;
    import org.springframework.http.server.ServerHttpResponse;
    import org.springframework.web.bind.annotation.ExceptionHandler;
    import org.springframework.web.bind.annotation.RestControllerAdvice;
    import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
    
    import javax.servlet.http.HttpServletRequest;
    
    // 拦截范围为 com.chensir.controller包下内容
    @RestControllerAdvice(basePackages = {"com.chensir.controller"})
    public class MyResponseBodyAdvice implements ResponseBodyAdvice {
        // 是否开启拦截 true开启 false不开启
        @Override
        public boolean supports(MethodParameter methodParameter, Class aClass) {
            // 此处应该改为true,否则除了异常外 走到此处为false后就直接返回,也不再继续往下走了！
            return true;
        }
    
        // 如果接口返回异常就在此处拦截 进行封装;value = Exception.class 对所有的异常均拦截！
        @ExceptionHandler(value = Exception.class)
        public Object defaultErrorHandler(HttpServletRequest req, Exception ex){
            ResponseDto<Object> responseDto = new ResponseDto<>();
            responseDto.setCode(501);
            responseDto.setMessage(ex.getMessage());
            return responseDto;
        }
    
        @Override
        public Object beforeBodyWrite(Object body, MethodParameter methodParameter, MediaType mediaType, Class aClass, ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse) {
            // 有的接口再返回时会自己封装code,message,data。如果body是ResponseDto类型的实例，那么就直接返回body
    //        if(body instanceof ResponseDto){
    //            return body;
    //        }
    
            ResponseDto<Object> responseDto = new ResponseDto<>();
            // 先用hutool定义为null
            String message = StrUtil.EMPTY;
            responseDto.setCode(0);
            responseDto.setMessage(message);
    
            if (body instanceof Page){
                Page page = (Page) body;
                int pages = page.getPages();//总页数
                long total = page.getTotal();//总条数
                Dict dict = Dict.create()
                        .set("total",total)
                        .set("pages",pages)
                        .set("item",body);
                responseDto.setData(dict);
            }else {
                responseDto.setData(body);
            }
    
            // 如果是string类型就用json封装一下;
            if (aClass == StringHttpMessageConverter.class) {
                return JSONUtil.toJsonStr(responseDto);
            } else {
                return responseDto;
            }
    
        }
    }

## ResponseDto<T> ##

package com.chensir.advice;
    
    import lombok.Data;
    
    import java.io.Serializable;
    
    // 泛型
    @Data
    public class ResponseDto<T> implements Serializable {
    
        // 返回码(内部拟定)
        private int code;
    
        // 返回信息
        private String message;
    
        private T data;
    }

## MyBatisConfig ##

package com.chensir.config;
    
    import com.github.pagehelper.PageInterceptor;
    import lombok.extern.slf4j.Slf4j;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.mybatis.spring.SqlSessionFactoryBean;
    import org.mybatis.spring.boot.autoconfigure.ConfigurationCustomizer;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.core.io.Resource;
    import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
    import org.springframework.core.io.support.ResourcePatternResolver;
    import org.springframework.util.CollectionUtils;
    
    import javax.sql.DataSource;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.Arrays;
    import java.util.List;
    
    @Configuration
    @Slf4j
    public class MyBatisConfig {
    
        @Autowired
        private ConfigurationCustomizer configurationCustomizer;
        /**
         * 自己注册SqlSessionFactory 目的是增强功能，添加分页插件
         * @param ds 代表数据源
         * @return
         * @throws Exception
         */
        @Bean
        public SqlSessionFactory sqlSessionFactory(DataSource ds) throws Exception {
            SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
            // 设置数据源
            factoryBean.setDataSource(ds);
    
            // 把分页插件设置到SqlSessionFactory插件库
            factoryBean.setPlugins(new PageInterceptor());
            // 配置mapper.xml地址
            factoryBean.setMapperLocations(resolveMapperLocations());
    
            //驼峰映射注册到SqlSessionFactory中
            org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
            configurationCustomizer.customize(configuration);
            factoryBean.setConfiguration(configuration);
    
    
            // 返回具体实例对象
            SqlSessionFactory bean = factoryBean.getObject();
            return bean;
        }
    
    
        /**
         * 开启驼峰映射
         * @return
         */
        @Bean
        public ConfigurationCustomizer configurationCustomizer(){
            return new ConfigurationCustomizer() {
                @Override
                public void customize(org.apache.ibatis.session.Configuration configuration) {
                    configuration.setMapUnderscoreToCamelCase(true);
                }
            };
        }
    
        /**
         * 查找 xxxMapper.xml
         * @return
         */
        public Resource[] resolveMapperLocations() {
            ResourcePatternResolver resourceResolver = new PathMatchingResourcePatternResolver();
            List<String> mapperLocations = new ArrayList<>();
            mapperLocations.add("classpath*:mapper/*Mapper.xml");
    //        mapperLocations.add("classpath*:com/meiwei/ping/dao/**/*Mapper.xml");
            List<Resource> resources = new ArrayList();
            if (!CollectionUtils.isEmpty(mapperLocations)) {
                for (String mapperLocation : mapperLocations) {
                    try {
                        Resource[] mappers = resourceResolver.getResources(mapperLocation);
                        resources.addAll(Arrays.asList(mappers));
                    } catch (IOException e) {
                        log.error("Get myBatis resources happened exception", e);
                    }
                }
            }
    
            return resources.toArray(new Resource[resources.size()]);
        }
    
    }

## UsersController ##

package com.chensir.controller;
    
    import com.chensir.entity.Users;
    import com.chensir.service.UsersService;
    import com.github.pagehelper.Page;
    import com.github.pagehelper.PageHelper;
    import com.github.pagehelper.PageInfo;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.annotation.Resource;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    @RestController
    public class UsersController {
    
        @Resource
        private UsersService usersService;
    
        @GetMapping("/demo1")
        public List selectUsersList(Integer pageNum,Integer pageSize) {
    
            // 启用分页，查询第一页，每页3条
            PageHelper.startPage(pageNum,pageSize);
            //-------------PageInfo方式---------------
    //        PageInfo<Users> usersPageInfo = new PageInfo<>(usersService.selectUsersList());
    //        return usersPageInfo;
            //-------------PageInfo方式---------------
    
            //-------------Page方式---------------
    //        List<Users> users = usersService.selectUsersList();
    //        Page page = (Page) users;
    //        int pages = page.getPages();
    //        long total = page.getTotal();
    //
    //
    //        Map<String,Object> pageMap = new HashMap<>();
    //        pageMap.put("pages",pages);
    //        pageMap.put("total",total);
    //        pageMap.put("items",users);
    //        return pageMap;
            //-------------Page方式---------------
    
    
            //-----------使用ResponseBodyAdvice------------
            List<Users> users = usersService.selectUsersList();
            return users;
            //-----------使用ResponseBodyAdvice------------
        }
    
        @GetMapping("/demo2")
        public Users selectUsers(){
            Users users = usersService.selectUsers();
            return users;
        }
    
        @GetMapping("/demo3")
        public Map selectUsersToMap(){
            return usersService.selectUsersToMap();
        }
    }

## UsersMapper ##

@Mapper
    public interface UsersMapper {
    
        List<Users> selectUsersList();
    
        Users selectUsers();
    
        Map<String,Object> selectUsersToMap();
    }

## UserMapper.xml ##

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="com.chensir.mapper.UsersMapper">
    
    
        <select id="selectUsersList" resultType="com.chensir.entity.Users">
            select * from users
        </select>
        <select id="selectUsers" resultType="com.chensir.entity.Users">
            select * from users where id = 1
        </select>
        <select id="selectUsersToMap" resultType="java.util.Map">
            select * from users where id = 1
        </select>
    </mapper>

## 结果 ##

{
      "code": 0,
      "message": "",
      "data": {
        "total": 5,
        "pages": 2,
        "item": [
          {
            "id": 1,
            "name": "chjnzkcn",
            "age": 18,
            "sex": "男",
            "tel": "123",
            "createTime": "2023-05-11",
            "updateTime": "2023-05-11"
          },
          {
            "id": 2,
            "name": "czvfzsvdv",
            "age": 20,
            "sex": "男",
            "tel": "2315",
            "createTime": "2023-05-11",
            "updateTime": "2023-05-11"
          },
          {
            "id": 3,
            "name": "sczvszv",
            "age": 18,
            "sex": "女",
            "tel": "2112321",
            "createTime": "2023-05-11",
            "updateTime": "2023-05-11"
          }
        ]
      }
    }

[aae30dfd75e8469db6b360e5e71a5aaf.png]: https://img-blog.csdnimg.cn/aae30dfd75e8469db6b360e5e71a5aaf.png