Struts2 文件上传 - 未调用 execute()

Question

I'm using Struts2 2.5.20 and have written a file upload action that almost works. I can see in the debugger that setReport(), setReportContentType() and setReportFileName() are being called and the parameter values are correct. However, the execute() method is never invoked. I tried following the call stack to see where it should have been called, but there's just layer after layer of interceptors that I can't find the bottom.

Does anyone know what the reason for execute() might be?

public class ImportReportAction extends CampaignerActionSupport implements ValidationAware
{
  private File              report;
  private String            reportContentType;
  private String            reportFileName;


  @Override
  public String execute() throws Exception
  {
    ...
    return SUCCESS;
  }

  public void setReport(
    File report)
  {
    this.report = report;
  }   

  public void setReportContentType(
    String reportContentType)
  {
    this.reportContentType = reportContentType;
  }

  @RequiredFieldValidator(type = ValidatorType.FIELD, key = "errors.required", messageParams = { "getText('labels.report.file')" })
  public void setReportFileName(
    String reportFileName)
  {
    this.reportFileName = reportFileName;
  }
}

Update: I've discovered that the problem is in having the RequiredFieldValidator annotation. When that is present, the validation always fails but the s:actionerror tag is not displaying any message. When the annotation is not present, it allows a user to not pick a file and still calls execute().

The new question is: how to I correctly annotate my class for validation of a file upload?

Answer 1

我必须删除 @RequiredFieldValidator 注释，使我的操作实现 ValidationAware，然后实现一个 validate() 方法并手动将验证放在那里。