系统找不到jsf2.0中指定的文件

Question

我在 eclipse ide 中使用 jsf2.0。我在本地文件夹中存储图像时遇到问题。图像存储在本地文件夹中，大小为 0 字节。图像被读取和写入 0 字节。

Backing Bean:

public class uploadImageAction {

public void handleFileUpload(FileUploadEvent event) throws IOException {


    FacesContext context = FacesContext.getCurrentInstance();
    PhotoBean photoBean = (PhotoBean) context.getApplication().evaluateExpressionGet(context, "#{photoBean}", PhotoBean.class);
    PhotoBean photoBean2 = (PhotoBean) context.getApplication().evaluateExpressionGet(context, "#{photoBean2}", PhotoBean.class);

    ExternalContext extContext=FacesContext.getCurrentInstance().getExternalContext();

    File file = new  File(extContext.getRealPath(event.getFile().getFileName()));


      System.out.println("Hibernate save image into database");
        Session session = HibernateUtil1.getSessionFactory().openSession();

        session.beginTransaction();

        //save image into database
        //File file = new File("D:\\1.gif");
        //byte[] bFile = new byte[(int) file.length()];
        //System.out.println("DDDDDDDDDDDD"+bFile);

        byte[] bfile = new byte[(int)file.length()];
        System.out.println("DDDDDDDDDDDD"+bfile);
        try {
             FileInputStream fileInputStream = new FileInputStream(file);
             //convert file into array of bytes
             fileInputStream.read(bfile);
             fileInputStream.close();
            } catch (Exception e) {
                System.out.println("Cannnoy");
             e.printStackTrace();
            }

        String urlImage = file.toString();

        String imageName = event.getFile().getFileName();


        photoBean.setPathName(file);

        //file = photoBean.getPathName();

        photoBean.setImageName(imageName);

        imageName = photoBean.getImageName();

        photoBean.setUrl(urlImage);

        urlImage = photoBean.getUrl();


    //  PhotoDaoService photoDaoService = new PhotoDaoService();

        System.out.println("+++++++++++++++++++++++++"+file);


 System.out.println("CHECK BYTES"+bfile);
     //   uploadImageBean upldImageBean = new uploadImageBean();
        //upldImageBean.setImageByte(bfile);
        photoBean.setByteImage(bfile);
        //avatar.setImage(bFile);
       // System.out.println("dfdffdf"+upldImageBean.setImageByte(bFile));


        session.save(photoBean);


        //Get image from database
         photoBean2 = (PhotoBean)session.get(PhotoBean.class, photoBean.getId());
        byte[] bImage = photoBean2.getByteImage();
        System.out.println("QQQQQQQQQQQQQQQ"+bImage);
        int i=0;
        try{
            FileOutputStream fos = new FileOutputStream("e:/out/out"+0+".jpg"); 
            fos.write(bImage);
            fos.close();
            FacesMessage msg = new FacesMessage("Succesful", event.getFile().getFileName()
                    + " is uploaded.");

                    FacesContext.getCurrentInstance().addMessage(null, msg);
        }catch(Exception e){
            e.printStackTrace();
            System.out.println("UPLOAD DISPLAY EXCEPTION");
        }

        session.getTransaction().commit();
    }

}

发生错误：

Hibernate save image into database
bytes[B@12fb7ef
java.io.FileNotFoundException: E:\Mecherie_project\.metadata\.plugins \org.eclipse.wst.server.core\tmp0\wtpwebapps\image_web\baby.jpg (The system cannot find  the file specified)

at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:120)
at image.uploadImageAction.handleFileUpload(uploadImageAction.java:45)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at   sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.sun.el.parser.AstValue.invoke(AstValue.java:234)

Answer 1

正如回答的那样很多 次 之前，您不应该不存储/定位上传的内容公共网络内容中的文件。您应该改用绝对路径。例如，

File file = new File("/path/to/images", filename);
// ...

上传的文件不会神奇地出现在扩展的 WAR 中，因此使用 FileInputStream 读取它根本不起作用。您必须从 event.getFile().getInputStream() 读取它，然后将其写入任意 OutputStream，例如 FileOutputStream。

但现在您的真正问题比之前的问题更加清晰。您似乎想将上传的文件保存在数据库中。那么不需要首先将文件存储在本地磁盘文件系统上。只需将接收到的字节直接流式传输到 byte[] 并将其保存在数据库中。

InputStream input = event.getFile().getInputstream();
ByteArrayOutputStream output = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];

for (int length; (length = input.read(buffer)) > -1;) {
    output.write(buffer, 0, length);
}

photoBean.setByteImage(output.toByteArray());