项目开始
初始化一个springboot项目
配置跨域
/**
* 解决跨域问题的配置
*/
@Configuration
public class CorsConfig implements WebMvcConfigurer {
/**
* 设置跨域
*/
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/**")
.allowedOriginPatterns("*")
.allowedMethods("GET", "HEAD", "POST", "PUT", "DELETE", "OPTIONS")
.allowCredentials(true)
.maxAge(3600)
.allowedHeaders("*");
}
}
配置分页
/**
* MybatisPlus配置
*
*/
@Configuration
@MapperScan("com.example.wublog.mapper")
public class MybatisPlusConfig {
/**
* 分页插件
*/
@Bean
public PaginationInterceptor paginationInterceptor() {
PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
return paginationInterceptor;
}
}
数据库建表
文章表
CREATE TABLE `blog`.`ms_article` (
`id` bigint(0) NOT NULL AUTO_INCREMENT,
`comment_counts` int(0) NULL DEFAULT NULL COMMENT '评论数量',
`create_date` bigint(0) NULL DEFAULT NULL COMMENT '创建时间',
`summary` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '简介',
`title` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '标题',
`view_counts` int(0) NULL DEFAULT NULL COMMENT '浏览数量',
`weight` int(0) NOT NULL COMMENT '是否置顶',
`author_id` bigint(0) NULL DEFAULT NULL COMMENT '作者id',
`body_id` bigint(0) NULL DEFAULT NULL COMMENT '内容id',
`category_id` int(0) NULL DEFAULT NULL COMMENT '类别id',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 25 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
标签表 id，文章id，标签id，通过文章id可以间接查到标签id
CREATE TABLE `blog`.`ms_tag` (
`id` bigint(0) NOT NULL AUTO_INCREMENT,
`article_id` bigint(0) NOT NULL,
`tag_id` bigint(0) NOT NULL,
PRIMARY KEY (`id`) USING BTREE,
INDEX `article_id`(`article_id`) USING BTREE,
INDEX `tag_id`(`tag_id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 1 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
用户表
CREATE TABLE `blog`.`ms_sys_user` (
`id` bigint(0) NOT NULL AUTO_INCREMENT,
`account` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '账号',
`admin` bit(1) NULL DEFAULT NULL COMMENT '是否管理员',
`avatar` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '头像',
`create_date` bigint(0) NULL DEFAULT NULL COMMENT '注册时间',
`deleted` bit(1) NULL DEFAULT NULL COMMENT '是否删除',
`email` varchar(128) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '邮箱',
`last_login` bigint(0) NULL DEFAULT NULL COMMENT '最后登录时间',
`mobile_phone_number` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '手机号',
`nickname` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '昵称',
`password` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '密码',
`salt` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '加密盐',
`status` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '状态',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 16 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
接口说明
接口url：/articles
请求方式：POST
请求参数
| 参数名称 | 参数类型 | 说明 |
|---|---|---|
| page | int | 当前页数 |
| pageSize | int | 每页显示的数量 |
返回数据
{
"success": true,
"code": 200,
"msg": "success",
"data": [
{
"id": 1,
"title": "springboot介绍以及入门案例",
"summary": "通过Spring Boot实现的服务，只需要依靠一个Java类，把它打包成jar，并通过`java -jar`命令就可以运行起来。\r\n\r\n这一切相较于传统Spring应用来说，已经变得非常的轻便、简单。",
"commentCounts": 2,
"viewCounts": 54,
"weight": 1,
"createDate": "2609-06-26 15:58",
"author": "12",
"body": null,
"tags": [
{
"id": 5,
"avatar": null,
"tagName": "444"
},
{
"id": 7,
"avatar": null,
"tagName": "22"
},
{
"id": 8,
"avatar": null,
"tagName": "11"
}
],
"categorys": null
},
{
"id": 9,
"title": "Vue.js 是什么",
"summary": "Vue (读音 /vjuː/，类似于 view) 是一套用于构建用户界面的渐进式框架。",
"commentCounts": 0,
"viewCounts": 3,
"weight": 0,
"createDate": "2609-06-27 11:25",
"author": "12",
"body": null,
"tags": [
{
"id": 7,
"avatar": null,
"tagName": "22"
}
],
"categorys": null
},
{
"id": 10,
"title": "Element相关",
"summary": "本节将介绍如何在项目中使用 Element。",
"commentCounts": 0,
"viewCounts": 3,
"weight": 0,
"createDate": "2609-06-27 11:25",
"author": "12",
"body": null,
"tags": [
{
"id": 5,
"avatar": null,
"tagName": "444"
},
{
"id": 6,
"avatar": null,
"tagName": "33"
},
{
"id": 7,
"avatar": null,
"tagName": "22"
},
{
"id": 8,
"avatar": null,
"tagName": "11"
}
],
"categorys": null
}
]
}
entity层
Tag
@Data
public class Tag {
private Long id;
private String avatar;
private String tagName;
}
SysUser
@Data
public class SysUser {
private Long id;
private String account;
private Integer admin;
private String avatar;
private Long createDate;
private Integer deleted;
private String email;
private Long lastLogin;
private String mobilePhoneNumber;
private String nickname;
private String password;
private String salt;
private String status;
}
Article
package com.example.wublog.pojo;
import lombok.Data;
@Data
public class Article {
public static final int Article_TOP = 1;
public static final int Article_Common = 0;
private Long id;
private String title;
private String summary;
private int commentCounts;
private int viewCounts;
/**
* 作者id
*/
private Long authorId;
/**
* 内容id
*/
private Long bodyId;
/**
*类别id
*/
private Long categoryId;
/**
* 置顶
*/
private int weight = Article_Common;
/**
* 创建时间
*/
private Long createDate;
}
统一结果封装
//统一结果封装
@Data
@AllArgsConstructor
public class Result {
private boolean success;
private int code;
private String msg;
private Object data;
public static Result success(Object data) {
return new Result(true,200,"success",data);
}
public static Result fail(int code,String msg) {
return new Result(false,code,msg,null);
}
}
controller层
@RestController
@RequestMapping("articles")
public class ArticleController {
@Autowired
private ArticleService articleService;
//Result是统一结果返回
@PostMapping
public Result articles(@RequestBody PageParams pageParams) {
//ArticleVo 页面接收的数据
List<ArticleVo> articles = articleService.listArticlesPage(pageParams);
return Result.success(articles);
}
}
与前端交互的Vo
@Data
public class ArticleVo {
private Long id;
private String title;
private String summary;
private int commentCounts;
private int viewCounts;
private int weight;
/**
* 创建时间
*/
private String createDate;
private String author;
private ArticleBodyVo body;
private List<TagVo> tags;
private List<CategoryVo> categorys;
}
service层
文章service接口
public interface ArticleService {
/**
* 分页查询文章列表
* @param pageParams
* @return
*/
List<ArticleVo> listArticlesPage(PageParams pageParams);
}
service接口的实现类
@Service
public class ArticleServiceImpl implements ArticleService {
@Autowired
private ArticleMapper articleMapper;
@Autowired
private TagService tagService;
@Autowired
private SysUserService sysUserService;
@Override
public Result listArticle(PageParams pageParams) {
/**
* 1、分页查询article数据库表
*/
Page<Article> page = new Page<>(pageParams.getPage(), pageParams.getPageSize());
LambdaQueryWrapper<Article> queryWrapper = new LambdaQueryWrapper<>();
//是否置顶进行排序, //时间倒序进行排列相当于order by create_data desc
queryWrapper.orderByDesc(Article::getWeight,Article::getCreateDate);
Page<Article> articlePage = articleMapper.selectPage(page, queryWrapper);
//分页查询
List<Article> records = articlePage.getRecords();
// 要返回我们定义的vo数据，就是对应的前端数据，不应该只返回现在的数据需要进一步进行处理
List<ArticleVo> articleVoList =copyList(records,true,true);
return Result.success(articleVoList);
}
private List<ArticleVo> copyList(List<Article> records,boolean isTag,boolean isAuthor) {
List<ArticleVo> articleVoList = new ArrayList<>();
for (Article record : records) {
articleVoList.add(copy(record,isTag,isAuthor));
}
return articleVoList;
}
private ArticleVo copy(Article article,boolean isTag,boolean isAuthor){
ArticleVo articleVo = new ArticleVo();
//BeanUtils.copyProperties用法 https://blog.csdn.net/Mr_linjw/article/details/50236279
BeanUtils.copyProperties(article, articleVo);
articleVo.setCreateDate(new DateTime(article.getCreateDate()).toString("yyyy-MM-dd HH:mm"));
//并不是所有的接口都需要标签和作者信息
if(isTag){
Long articleId = article.getId();
articleVo.setTags(tagService.findTagsByArticleId(articleId));
}
if (isAuthor) {
//拿到作者id
Long authorId = article.getAuthorId();
articleVo.setAuthor(sysUserService.findUserById(authorId).getNickname());
}
return articleVo;
}
}
用户的service接口
public interface UserService {
SysUser findUserById(Long userId);
}
service的接口实现类
@Service
public class SysUserServiceImpl implements SysUserService {
@Autowired
private SysUserMapper sysUserMapper;
@Override
public SysUser findUserById(Long id) {
//根据id查询
//为防止sysUser为空增加一个判断
SysUser sysUser = sysUserMapper.selectById(id);
if (sysUser == null){
sysUser = new SysUser();
sysUser.setNickname("码神之路");
}
return sysUser;
}
}
Tag的service接口
public interface TagsService {
List<TagVo> findTagsByArticleId(Long id);
}
Tag的service实现类
@Service
public class TagsServiceImpl implements TagsService {
@Autowired
private TagMapper tagMapper;
/**
* ms_article_tag是文章和标签的关联表
* ms_tag为单纯的标签的表
* @param articleId
* @return
*/
@Override
public List<TagVo> findTagsByArticleId(Long articleId) {
//mybatisplus无法进行多表查询
List<Tag> tags = tagMapper.findTagsByArticleId(articleId);
return copyList(tags);
}
private List<TagVo> copyList(List<Tag> tagList) {
List<TagVo> tagVoList = new ArrayList<>();
for (Tag tag : tagList) {
tagVoList.add(copy(tag));
}
return tagVoList;
}
private TagVo copy(Tag tag) {
TagVo tagVo = new TagVo();
BeanUtils.copyProperties(tag, tagVo);
return tagVo;
}
}
DAO层
文章的Dao层,由于我们直接继承了mybatisplus的BaseMapper所以基本的增删改查都不用再写了
public interface ArticleMapper extends BaseMapper<Article> {
}
标签的Dao层
public interface TagMapper extends BaseMapper<Tag> {
List<Tag> findTagsByArticleId(Long articleId);
}
作者的Dao层
public interface SysUserMapper extends BaseMapper<SysUser> {
}
MybatisPlus不支持多表查询,我们需要建立自己的xml文件进行联合查询操作
<?xml version="1.0" encoding="UTF-8" ?>
<!--MyBatis配置文件-->
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.wublog.mapper.TagMapper">
<sql id="all">
id,avatar,tag_name as tagName
</sql>
<!-- List<Tag> findTagsByArticleId(Long articleId);
在这个文件中，id代表方法名，parameterType表示输入变量的名字，resultType表示泛型的类型-->
<select id="findTagsByArticleId" parameterType="long" resultType="com.example.wublog.mapper.TagMapper">
select id,avatar,tag_name as tagName from ms_tag
where id in (select tag_id from ms_article_tag where article_id=#{articleId})
</select>
</mapper>
Ps:
- 使用@AutoWired注解mapper爆红，改@Resource
- 对象拷贝BeanUtil的用法blog.csdn.net/Mr_linjw/ar…
