Field error in object 'books' on field 'bookId': rejected value [null]; codes [typeMismatch.books.bo

最新推荐文章于 2025-04-23 16:48:48 发布

原创最新推荐文章于 2025-04-23 16:48:48 发布

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博客讲述了在使用Spring时遇到的一个验证错误，具体为Field error in object 'books' on field 'bookId'，错误信息显示尝试将null值转换为int类型的bookId失败。作者尝试将books的参数重写为bookID后解决了问题，但当再次改回bookId时，错误未再现，怀疑可能是IDEA的bug。文中提供了Books类的部分代码，并表达了对问题原因的疑惑。

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错误信息

01-May-2020 20:43:35.866 WARNING [http-nio-555-exec-1] org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.logException Resolved [org.springframework.validation.BindException: org.springframework.validation.BeanPropertyBindingResult: 1 errors
Field error in object ‘books’ on field ‘bookId’: rejected value [null]; codes [typeMismatch.books.bookId,typeMismatch.bookId,typeMismatch.int,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [books.bookId,bookId]; arguments []; default message [bookId]]; default message [Failed to convert value of type ‘null’ to required type ‘int’; nested exception is org.springframework.core.convert.ConversionFailedException: Failed to convert from type [null] to type [int] for value ‘null’; nested exception is java.lang.IllegalArgumentException: A null value cannot be assigned to a primitive type]]

解决方法
底层的books的参数重写为bookID
PS: 但是当我重写回bookId的时候又没有问题了,怀疑是idea有bug

在这里插入图片描述
下面是Books类的代码,一开始bookId报错,重写成bookID后不报错了,但是再次重写成bookId不报错.

package com.psj.pojo;

public class Books {
    private int bookId;
    private String bookName;
    private int bookCounts;
    private String detail;

    public Books() {
    }


    public int getBookId() {
        return bookId;
    }

    public void setBookId(int bookId) {
        this.bookId = bookId;
    }

    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public int getBookCounts() {
        return bookCounts;
    }

    public void setBookCounts(int bookCounts) {
        this.bookCounts = bookCounts;
    }

    public String getDetail() {
        return detail;
    }

    public void setDetail(String detail) {
        this.detail = detail;
    }


    public Books(int bookId, String bookName, int bookCounts, String detail) {
        this.bookId = bookId;
        this.bookName = bookName;
        this.bookCounts = bookCounts;
        this.detail = detail;
    }
    @Override
    public String toString() {
        return "Books{" +
                "bookId=" + bookId +
                ", bookName='" + bookName + '\'' +
                ", bookCounts=" + bookCounts +
                ", detail='" + detail + '\'' +
                '}';
    }
}