java - 如何将对象作为 URI 行中的查询参数传递？

Question

您能帮我解释一下我应该如何传递作者值吗？

@GetMapping(value = "/search")
    public ResponseEntity<List<Book>> searchBooksByTitleAndAuthor(
            @RequestParam(value = "title", required = false) final String title,
            @RequestParam(value = "author", required = false) final Author author) {
        HttpStatus httpStatus = HttpStatus.OK;
        List<Book> books = null;
        if (title == null && author == null) {
            log.info("Empty request");
            httpStatus = HttpStatus.BAD_REQUEST;
        } else if (title == null || author == null) {
            books = bookService.getBooksByTitleOrAuthor(title, author);
        } else {
            Optional<Book> book = bookService.getBookByTitleAndAuthor(title, author);
            if (book.isPresent()) {
                books = Arrays.asList(book.get());
            }
        }
        if (books == null) {
            return new ResponseEntity<>(httpStatus);
        } else {
            return new ResponseEntity<>(books, httpStatus);
        }
    }

和 Author 类看起来像:

@Entity
@NoArgsConstructor
@AllArgsConstructor
@Getter
@EqualsAndHashCode
@ToString
public final class Author {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Long id;

    private String name;

    private LocalDate dateOfBirth;

    private String bio;
}

在这种情况下使用author或@RequestParam而不是请求正文是一个好方法吗？我考虑过仅请求作者姓名的字符串，但这会影响服务的方法。

Answer 1

根据https://lankydanblog.com/2017/03/11/passing-data-transfer-objects-with-get-in-spring-boot/ ，...您可以(在 author.dateOfBirth 上设置一些转换注释后):

1. 在字符串参数上使用@RequestParam(并让您的 Controller /某人进行转换):

       ..., @RequestParam(value = "author", required = false) final String author) { 
   
        ...final Author author = new ObjectMapper().setDateFormat(simpleDateFormat)
                                .readValue(author, Author.class);
   

   在这种情况下，您会请求:

   http://localhost:8080/myApp/search?title=foo&author={"id"="1",...}
   

2. 或者:省略@RequestParam，但传递对象(并让 spring 负责转换):

   ...(@RequestParam(value = "title", required = false) final String title,
        final Author author)
   

   并请求如下:

   http://localhost:8080/myApp/search?title=foo&id=1&name=Donald E. Knuth&...
   

另请参阅:

• Spring MVC: Complex object as GET @RequestParam
• Spring REST - binding GET parameters to nested objects
• Spring map GET request parameters to POJO automatically