java 无法将“org.springframework.web.multipart.commons.CommonsMultipartFile”类型的值转换为所需类型
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Failed to convert value of type 'org.springframework.web.multipart.commons.CommonsMultipartFile' to required type
提问by gstackoverflow
I have following controller method:
我有以下控制器方法：
@RequestMapping(value = "/owner/terminals/save", method = RequestMethod.POST)
public String saveTerminal( @RequestParam(value = "name") String name,
@RequestParam(value = "file") @Valid OnlyForImagesFileWrapper file,
BindingResult bindingResult )
{
...
and I see the following stacktrace:
我看到以下堆栈跟踪：
org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'org.springframework.web.multipart.commons.CommonsMultipartFile' to required type 'com.terminal.domain.validation.OnlyForImagesFileWrapper'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [org.springframework.web.multipart.commons.CommonsMultipartFile] to required type [com.terminal.domain.validation.OnlyForImagesFileWrapper]: no matching editors or conversion strategy found
at org.springframework.beans.TypeConverterSupport.doConvert(TypeConverterSupport.java:74)
....
Caused by: java.lang.IllegalStateException: Cannot convert value of type [org.springframework.web.multipart.commons.CommonsMultipartFile] to required type [com.terminal.domain.validation.OnlyForImagesFileWrapper]: no matching editors or conversion strategy found
at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:267)
... 71 more
OnlyForImagesFileWrapper source:
OnlyForImagesFileWrapper 来源：
public class OnlyForImagesFileWrapper {
@Extensions(imageFormats = {".jpg",".png",".gif",".bmp"}, videoFormats = {})
private MultipartFile multipartFile;
...
}
How to avoid the problem?
如何避免问题？
Where can I set conversion politic for this controller method for multipart file?
我在哪里可以为多部分文件的这个控制器方法设置转换策略？
P.S.
聚苯乙烯
I tryed to write my custom initbinder:
我尝试编写我的自定义 initbinder：
@InitBinder
public void initBinder(WebDataBinder binder) {
binder.registerCustomEditor(CommonsMultipartFile.class, new PropertyEditorSupport() {
@Override
public void setValue(Object file) {
setValue(new OnlyForImagesFileWrapper((MultipartFile) file));
}
});
}
But this method doesn't invoke when I submit form and I see stacktrace mentioned above.
但是当我提交表单并且我看到上面提到的堆栈跟踪时，此方法不会调用。
P.S.
聚苯乙烯
result after M. Deinuminstruction execution(when I inside saveTerminalmethod):
M. Deinum指令执行后的结果（当我在saveTerminal方法中时）：
Also I noticed that my initbinder method doesn't invoke.
我还注意到我的 initbinder 方法没有调用。
More details about my code(state after M. Denium advice):
有关我的代码的更多详细信息（在 M. Denium 建议之后声明）：
jsp:
jsp：
<input type="file" id="newFile" name="file" class="file" size="21.5" accept=".jpg,.png,.gif,.bmp" style="opacity: 0;">
arguments of controller method:
控制器方法的参数：
...
@ModelAttribute @Valid OnlyForImagesFileWrapper wrapper,
BindingResult bindingResult,
...
采纳答案by M. Deinum
As I commented you are making things too complex. Change your wrapper to the following (with the appropriate getters and setters).
正如我评论的那样，你让事情变得太复杂了。将您的包装器更改为以下内容（使用适当的 getter 和 setter）。
public class OnlyForImagesFileWrapper {
@Extensions(imageFormats = {".jpg",".png",".gif",".bmp"}, videoFormats = {})
private MultipartFile file;
private String name;
...
}
Then your controller method
然后你的控制器方法
@RequestMapping(value = "/owner/terminals/save", method = RequestMethod.POST)
public String saveTerminal( @ModelAttribute @Valid OnlyForImagesFileWrapper wrapper, BindingResult bindingResult ) { ... }
And of course in your configuration make sure you have a MultipartFileResolverconfigured to properly handle the MultipartFileargument as explained in the reference guide.
当然，在你的配置中，确保你有一个MultipartFileResolver配置来正确处理参考指南中MultipartFile解释的参数。
