本篇文章的主要内容是关于项目的跨域配置和给项目添加restful风格接口。
重点是文件粘贴

一、 跨域

跨域问题暂时也就那样，解决方法就是复制粘贴一个不知道从哪里来的CorsConfig文件，这样就可以解决问题：

import jakarta.servlet.*;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.context.annotation.Configuration;

import java.io.IOException;


/**
 * @author oyan
 * @date 2024/5/22 17:20
 * @description CorsConfig
 */
@Configuration
public class CorsConfig implements Filter {
    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        HttpServletRequest request = (HttpServletRequest) req;

        String origin = request.getHeader("Origin");
        if(origin!=null) {
            response.setHeader("Access-Control-Allow-Origin", origin);
        }

        String headers = request.getHeader("Access-Control-Request-Headers");
        if(headers!=null) {
            response.setHeader("Access-Control-Allow-Headers", headers);
            response.setHeader("Access-Control-Expose-Headers", headers);
        }

        response.setHeader("Access-Control-Allow-Methods", "*");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Credentials", "true");

        chain.doFilter(request, response);
    }

    @Override
    public void init(FilterConfig filterConfig) {

    }

    @Override
    public void destroy() {
    }
}

二、Restful风格

1. 什么是restful风格？

其实就是长这个样的：

就是返回的参数是这样的，很规整的。

2. 项目文件结构

接下来是这样的结构，你需要新建如下的包

3. 新建文件

新建枚举CodeEnum

/**
 * @author oyan
 * @date 2024/5/22 17:23
 * @description 枚举
 */
public enum CodeEnum {
    SUCCESS(200,"操作成功"),
    ERROR(400,"error"),
    TOKEN_NULL(403,"token不存在"),
    USER_INFO_ERROR(405,"用户信息错误"),
    FAIL_APPLY(407,"请求失败"),
    ROLE_ERROR(406,"角色错误"),
    TOKEN_ILLEGAL(408,"token不合法");



    int code;
    String msg;

    CodeEnum(int code, String message){
        this.code=code;
        this.msg=message;
    }
    public int getCode(){return code;}
    public String getMsg(){return msg;}
    public String toString(){
        return "\"{code\":\""+ this.code +"\","+
                "\"msg\":\""+ this.msg+"\"}";
    }
}

新建记录Rest

/**
 * @author Administrator
 * @date 2024/5/22 17:25
 * @description Rest restful风格的结果
 */
public record Rest<T>(int code, String message, T data) {
    public static <T> Rest<T> success(T data){return new Rest<>(CodeEnum.SUCCESS.getCode(),CodeEnum.SUCCESS.getMsg(),data);}
    public static <T> Rest<T> success(){return new Rest<>(CodeEnum.SUCCESS.getCode(), CodeEnum.SUCCESS.getMsg(), null);}
    public static <T> Rest<T> success(String msg){return new Rest<>(CodeEnum.SUCCESS.getCode(), msg,null);}
    public static <T> Rest<T> failure(CodeEnum codeEnum){return new Rest<>(codeEnum.getCode(),codeEnum.getMsg(),null);}
    public static <T> Rest<T> failure(String msg){return new Rest<>(400,msg,null);}
}

4. 在Controller中进行修改

以CategoryController为例：

@RestController
@RequestMapping("/category")
public class CategoryController {
    @Autowired
    private CategoryService categoryService;

    @GetMapping("/all")
    public Rest findAll() {
        try{
            return Rest.success(categoryService.findAll());
        }catch (Exception e){
            return Rest.failure(e.getMessage());
        }
    }

    @PostMapping("/input")
    public Rest insert(@RequestParam("name") String name, @RequestParam("parentCategory") Integer parentCategory, @RequestParam("level") Integer level) {
        System.out.println(name+parentCategory+level);
        Category category = new Category();
        category.setName(name);
        category.setParentCategory(parentCategory);
        category.setLevel(level);
        try {
            categoryService.insert(category);
            return Rest.success();
        }catch(Exception e) {
            return Rest.failure(e.getMessage());
        }

    }

    @PostMapping("/delete")
    public Rest delete(@RequestParam("id") Integer id) {
        try {
            categoryService.delete(id);
            return Rest.success();
        }catch (Exception e){
            return Rest.failure(e.getMessage());
        }

    }
    @PostMapping("/find")
    public Rest getCategoryById(@RequestParam("id") Integer id) {
        try {
            Category category = categoryService.getCategoryById(id);
            if(category == null){
                return Rest.failure("查询结果为空/编号不存在");
            }
            return Rest.success(category);
        }catch (Exception e){
            return Rest.failure(e.getMessage());
        }
    }


}