struts2 File标签上传文件

1、action.class

private File pictureType;
    private String pictureTypeContentType;
    private String pictureTypeFileName;

public String editType() throws IOException{
        Type t=typeService.find(Type.class, id);
        System.out.println("id="+id);
        System.out.println(UploadPath);
        System.out.println(pictureTypeFileName);

        File saved=new File(UploadPath+Constants.TypeDir, t.getId()+"."+pictureTypeContentType.split("/")[1]);

        InputStream ins=null;
        OutputStream ous=null;
        try {
            saved.getParentFile().mkdirs();
            ins=new FileInputStream(pictureType);
            ous=new FileOutputStream(saved);
            byte[] b=new byte[1024];
            int len=0;
            while((len=ins.read(b))!=-1){
                ous.write(b, 0, len);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            if(ous!=null){
                ous.close();
            }
            if(ins!=null){
                ins.close();
            }
            t.setPicUrl(Constants.TypeDir+"/"+t.getId()+"."
                    + pictureTypeContentType.split("/")[1]);
            typeService.save(t);
        }
        return SUCCESS;
    }

2、表单

<s:form action="editType_manage" enctype="multipart/form-data">
        <s:file label="修改商店图片" name="pictureType"></s:file>
        <s:submit value="确认修改" />
    </s:form>

3、action得不到文件的几个原因

（1）三个变量，没有get-set方法

（2）Form没有设置enctype="multipart/form-data"