SpringBoot +thymeleaf +layui 提交更新接口提示：JSON parse error: Unrecognized token ‘bookId‘: was expecting-蒲公英云

SpringBoot +thymeleaf +layui 提交更新接口提示：JSON parse error: Unrecognized token ‘bookId‘: was expecting

LayUI 前端代码：

form.on('submit(formDemo)',function(messge){
                 console.log(messge.field);
                 console.log(obj.data);
                    $.ajax({
                            url:"/api/book/update",
                            type:"POST",
                            contentType: "application/json; charset=utf-8",
                            dataType: "json",   
                            data: {
                                "bookId":data.bookId,
                                "bookName":data.bookName,
                                   "bookAuthor":data.bookAuthor,
                                   "bookPublish":data.bookPublish,
                                   "booCategory":messge.field.booCategory,
                                   "bookPrice": data.bookPrice
                            },
                            success:function (msg) {
                                console.log(msg);
                                // var returnCode = msg.returnValue//取得返回数据（Sting类型的字符串）的信息进行取值判断
                                if (msg) {
                                    //layer.closeAll('loading');
                                    //layer.load(2);
                                    layer.msg("修改成功", {icon: 6});
                                    // 加载层 - 风格
                                } else {
                                    layer.msg("修改失败", {icon: 5});
                                }
                            }
                        })
                        return false;//阻止表单跳转,网页url不显示提交的参数。
                    })
    }

返回数据格式不规范.当dataType指定为json后,1.4+以上的jquery版本对json格式要求更加严格.如果不是严格的json格式,就不能正常执行success回调函数.

JSON格式:　 
1）键名称：用双引号 括起 　　 
2）字符串：用使用双引号 括起 
3）数字，布尔类型不需要 使用双引号 括起

调整后的代码：

//提交编辑表单
        form.on('submit(formDemo)',function(messge){
                 console.log(messge.field);
                 console.log(obj.data);
                 var str={
                                "bookId":data.bookId,
                                "bookName":data.bookName,
                                   "bookAuthor":data.bookAuthor,
                                   "bookPublish":data.bookPublish,
                                   "booCategory":messge.field.booCategory,
                                   "bookPrice": data.bookPrice
                            };
                    $.ajax({
                            url:"/api/book/update",
                            type:"POST",
                            contentType: "application/json; charset=utf-8",
                            dataType: "json",   
                            data: JSON.stringify(str),
                            success:function (msg) {
                                console.log(msg);
                                // var returnCode = msg.returnValue//取得返回数据（Sting类型的字符串）的信息进行取值判断
                                if (msg) {
                                    //layer.closeAll('loading');
                                    //layer.load(2);
                                    layer.msg("修改成功", {icon: 6});
                                    // 加载层 - 风格
                                } else {
                                    layer.msg("修改失败", {icon: 5});
                                }
                            }
                        })
                        return false;//阻止表单跳转,网页url不显示提交的参数。
                    })
    }