SpringBoot 仿B站后端项目实战 Day01

                用户服务： 注册登录 /大会员权限/ 查找视频
                在线视频流播放+实时弹幕
                管理后台 视频上传/数据统计/系统消息推送

               SpringBoot + MySql + Mybatis + Maven

               前端 ： 服务转发 + 负载均衡
               后端：  业务处理 + 功能实现
                         缓存 + 队列

               Windows系统
               IDEA软件
               JDK1.8 / Maven

IDEA 中 配置JDK
设置本地Maven setting文件
重写IDEA默认配置

添加SpringBoot依赖 pom依赖
启动入口

        
            mysql
            mysql-connector-java
            8.0.28
        

        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            2.2.2
        

            org.springframework.boot
            spring-boot-devtools
            2.6.4

POST   （不具有幂等性）
      1. 文章组发送消息
      2. 注册用户
      3. 提交表单
GET
DELETE
PUT   用于请求中的负载创建或者替换资源    具有幂等性(一次调用或多次调用等价，不会有副作用)

package com.mao.bilibili.api;



import org.springframework.web.bind.annotation.*;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;


@RestController
public class RestfulApi {

    private final Map> datamap;

    public RestfulApi(){
        datamap = new HashMap<>();
        for (int i = 1; i < 3; i++) {
            HashMap data = new HashMap<>();
            data.put("id",i);
            data.put("name","name"+i);
            datamap.put(i,data);
        }
    }

    @GetMapping("/objects/{id}")
    public Map getData(@PathVariable("id") Integer id){
        return datamap.get(id);
    }

    @DeleteMapping("/objects/{id}")
    public String deleteData(@PathVariable("id") Integer id){
        datamap.remove(id);
        return "delete success";
    }

    @PostMapping("/objects")    //添加数据
    public String postData(@RequestBody Map data){
        //先获取最后的id值
        Integer[] ts = datamap.keySet().toArray(new Integer[0]);
        Arrays.sort(ts);
        int id = ts[ts.length - 1] + 1; //要添加的id值
        datamap.put(id,data);
        return "post success";
    }

    @PutMapping("/objects")
    public String putData(@RequestBody Map data){
        //先看datamap中是否有相同id值的
        Integer id = Integer.valueOf(String.valueOf(data.get("id")));
        Map containedData = datamap.get(id);
        if (containedData == null){
            Integer[] ts = datamap.keySet().toArray(new Integer[0]);
            Arrays.sort(ts);
            int nextId = ts[ts.length - 1] + 1; //要添加的id值
            datamap.put(nextId,data);
        }else {
            datamap.put(id,data);
        }
        return "put success";
    }

}

一些规范

package com.mao.bilibili.domain;

import lombok.Data;


@Data
public class JsonResponse {
    private String code;
    private String msg;
    private T data;

    public JsonResponse(String code,String msg){
        this.code =code;
        this.msg = msg;
    }

    public JsonResponse(T data){
        this.data = data;
        this.code = "0";
        this.msg = "success";
    }

    // 成功返回前端无数据
    public static JsonResponse success(){
        return new JsonResponse(null);
    }
    // 返回前端有数据
    public static JsonResponse success(String data){
        return new JsonResponse<>(data);
    }
    // 失败
    public static JsonResponse fail(){
        return new JsonResponse("1","fail");
    }
    // 返回特定状态码
    public static JsonResponse fail(String code,String msg){
        return new JsonResponse<>(code, msg);
    }
}

@Configuration
public class JsonHttpMessageConverterConfig {

    @Bean
    @Primary //提高优先级
    public HttpMessageConverters fastJsonHttpMessageConverters() {
        FastJsonHttpMessageConverter messageConverter = new FastJsonHttpMessageConverter();
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setDateFormat("yyyy-MM-dd HH:mm:ss");
        fastJsonConfig.setSerializerFeatures(
                SerializerFeature.PrettyFormat,
                //List字段如果为null,输出为[],而非null
                SerializerFeature.WriteNullListAsEmpty,
                //字符类型字段如果为null,输出为"",而非null
                SerializerFeature.WriteNullStringAsEmpty,
                //Boolean字段如果为null,输出为false,而非null
                SerializerFeature.WriteNullBooleanAsFalse,
                //消除对同一对象循环引用的问题，默认为false（如果不配置有可能会进入死循环）
                SerializerFeature.DisableCircularReferenceDetect,
                //是否输出值为null的字段,默认为false。
                SerializerFeature.WriteMapNullValue,
                SerializerFeature.MapSortField
        );
        messageConverter.setFastJsonConfig(fastJsonConfig);
        return new HttpMessageConverters(messageConverter);
    }
}

@ControllerAdvice       //Controller增强器
@Order(Ordered.HIGHEST_PRECEDENCE)
public class CommonGlobalExceptionHandler {

    @ExceptionHandler(value = Exception.class)
    @ResponseBody
    public JsonResponse commonExceptionHandler(HttpServletRequest request,Exception e){
        String errorMsg = e.getMessage();
        if (e instanceof ConditionException){
            String errorCode = ((ConditionException) e).getCode();
            return new JsonResponse<>(errorCode,errorMsg);
        }else {
            return new JsonResponse<>("500",errorMsg);
        }
    }
}

public class ConditionException extends RuntimeException{

    private static final long serialVersionUID = 1L;

    private String code;

    public ConditionException(String code,String name){
        super(name);
        this.code = code;
    }

    public ConditionException(String name){
        super(name);
        this.code = "500";   //通用异常
    }

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }
}

```java

{
        super(name);
        this.code = code;
    }

    public ConditionException(String name){
        super(name);
        this.code = "500";   //通用异常
    }

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }
}