springbootProblemDetail

一直依赖 Spring Boot 默认的异常反馈内容比较单一，包含 Http Status Code, 时间，异常信息。但具体异常原因没有体现。这次 Spring Boot3对错误信息增强了。

RFC7807

RFC 7807 (Problem Details for HTTP APIs) : RFC 7807: Problem Details for HTTP APIs (rfc-editor.org)
RESTFul 服务中通常需要在响应体中包含错误详情，Spring 框架支持”Problem Details“。定义了Http 应答错误的处理细节，增强了响应错误的内容。包含标准和非标准的字段。同时支持 json 和 xm 两种格式。
基于 Http 协议的请求，可通过 Htp Status Code 分析响应结果，200 为成功， 4XX 为客户端错误，500 是服务器程序代码异常。status code 过于简单,不能进一步说明具体的错误原因和解决途径。比如 http status code 403.但并不能说明”是什么导致了 403“，以及如何解决问题。Http 状态代码可帮助我们区分错误和成功状态，但没法区分得太细致。RFC7807中对这些做了规范的定义。

配置文件

product:
  books:
    - isbn: book01
      name: java
      author: lisi
    - isbn: book02
      name: tomcat
      author: zhangsan
    - isbn: book03
      name: mybatis
      author: wangwu
# 访问地址
server:
  servlet:
    context-path: /api

# 开启RFC 7807
spring:
  mvc:
    problemdetails:
      enabled: true

springboot支持ProblemDetail

controller

@RestController
public class BookController {

    //注入BookContainer
    @Autowired
    private BookContainer bookContainer;

    @GetMapping("/book")
    public BookRecord getBook(String isbn){
        Optional<BookRecord> bookRecord = bookContainer.getBooks().stream().filter(el ->
                el.isbn().equals(isbn)
        ).findFirst();
        if(bookRecord.isEmpty()){
            throw new BookNotFoundException("isbn:" + isbn + "->没有此图书");
            
        }
        return bookRecord.get();
    }
}

pojo

public record BookRecord(String isbn, String name, String author) {
}

config

@Setter
@Getter
@ConfigurationProperties(prefix = "product")
public class BookContainer {
    private List<BookRecord> books;
}

exception

public class BookNotFoundException extends RuntimeException{
    public BookNotFoundException() {
        super();
    }

    public BookNotFoundException(String message) {
        super(message);
    }
}

handler(处理异常)

@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler({BookNotFoundException.class})
    public ProblemDetail handlerBookNotFoundException(BookNotFoundException e){
        //创建对象
        ProblemDetail problemDetail = ProblemDetail.forStatusAndDetail(HttpStatus.NOT_FOUND, e.getMessage());
        //设置值
        problemDetail.setType(URI.create("/api/probs/not_find"));
        problemDetail.setTitle("图书异常");
        //自定义字段
        problemDetail.setProperty("时间", Instant.now());

        return problemDetail;
    }
}

启动类

@EnableConfigurationProperties({BookContainer.class})
@SpringBootApplication
public class Lesson12ProblemDetailApplication {

    public static void main(String[] args) {
        SpringApplication.run(Lesson12ProblemDetailApplication.class, args);
    }

}

ErrorResponse

Spring Boot 识别ErrorResponse 类型作为异常的应答结果可以直接使用 ErrorResponse 作为异常处理方法的返回值，ErrorResponseException 是 ErrorResponse 的基本实现类
config, pojo, controller同上
exp

public class IsbnNotFoundException extends ErrorResponseException {
    public IsbnNotFoundException(HttpStatus httpStatus, String detail){
        super(httpStatus, createProblemDetail(httpStatus, detail), null);
    }

    private static ProblemDetail createProblemDetail(HttpStatus status, String detail){
        //封装
        ProblemDetail problemDetail = ProblemDetail.forStatus(status);
        problemDetail.setType(URI.create("/api/probs/not-find"));
        problemDetail.setTitle("图书异常");
        problemDetail.setDetail(detail);
        //自定义字段
        problemDetail.setProperty("严重程度", "低");

        return problemDetail;
    }
}

handler

public class GlobalExceptionHandler {
  @ExceptionHandler({BookNotFoundException.class})
    public ErrorResponse handlerException(BookNotFoundException e){
        ErrorResponse errorResponse = new ErrorResponseException(HttpStatus.NOT_FOUND, e);
        return errorResponse;
    }
}

错误信息

{
  "type": "/api/probs/not-find",
  "title": "图书异常",
  "status": 404,
  "detail": "isbn:book06->没有此图书",
  "instance": "/api/book",
  "严重程度": "低"
}