[問題]spring boot 報錯 NumberFormatException

看板java作者think12381時間5年前 (2019/12/12 22:33)推噓5(5推 0噓 13→)

留言18則, 7人參與討論串1/1

請問一下各位大大我目前正在學習Java spring boot 開發環境是採用 idea 目的是要採用網頁去DB裡面撈資料出來都會產生以下錯誤 Failed to convert value of type 'java.lang.String' to required type 'long'; nested exception is java.lang.NumberFormatException: For input string: "books" 看起來是說自串不能轉long 但是我這樣要怎麼對到 html去 google許久還是查不到解法請教各位大神謝謝以下是局部代碼實體 =========================================== @Entity public class Book2 { @Id @GeneratedValue(strategy = GenerationType.AUTO) private long id; private String name; private int status; private String author; private String description; =============================================== controller @GetMapping("/booklist/{id}") public String ListBook(@PathVariable("id") long id, Model model){ Optional<Book2> book2 = bookService.getOne(id); if(book2 == null){ book2 = Optional.of(new Book2()); } model.addAttribute("book", book2); System.out.println(book2.get().getName()+ " " + book2.get().getId() + " "+ book2.get().getAuthor()+ " "+ book2.get().getDescription()+ " "+ book2.get().getStatus()); return "books"; ============================================================================= book repository public interface BookRepository extends JpaRepository<Book2,Long> { ============================================================================== service @Service public class BookService { @Autowired private BookRepository bookRepository; =========================================================================== books.html <body> <div class = "container" style="max-width: 700px"> <h2 class = "page-header" style="margin-top: 50px">書單內容</h2> <div class="well"> <p> <strong> 作者 </strong> <span th:text = "${book.author}"> bb </span> </p> <p> <strong> 描述 </strong> <span th:text = "${book.description}"> cc </span> </p> <p> <strong> 書名 </strong> <span th:text = "${book.name}"> aa </span> </p> <p> <strong> 狀態 </strong> <span th:text = "${book.status}"> dd </span> </p> </div> </div> -- ※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 220.141.140.205 (臺灣) ※ 文章網址: https://www.ptt.cc/bbs/java/M.1576161180.A.50C.html

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ssccg

12/12 23:09, 5年前 , 1^F

12/12 23:09, 1^F

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think12381

12/13 06:57, 5年前 , 2^F

12/13 06:57, 2^F

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think12381

12/13 06:57, 5年前 , 3^F

12/13 06:57, 3^F