Question

我使用此代码并尝试从服务器下载png图片。这是代码

import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.imageio.ImageIO;
import org.apache.commons.net.ftp.FTPClient;
public class NetTest {
  public static void main(String[] args){
    FTPClient client = new FTPClient( );
    OutputStream outStream;
    try {

      client.connect( "server" );
      client.login("noman@mindzone.co.in", "pass");

      String remoteFile = "Pages/page0001.png";
      outStream = new FileOutputStream( "C:\\asd.png" );
      client.retrieveFile(remoteFile, outStream);

    } catch(IOException ioe) {
      ioe.printStackTrace();
      System.out.println( "Error communicating with FTP server." );
    } finally {
      try {
        client.disconnect( );
      } catch (IOException e) {
        System.out.println( "Problem disconnecting from FTP server" );
      }
    }

  }
}

此代码没有给我任何错误但是当我打开图像时它会显示无效图像。

Answer 1

这个主题是你的解决方案：

http://www.ajaxapp.com/2009/02/21/a-simple-java-ftp-connection-file-download-and-upload/

Answer 2

您的图像已损坏，因为FTPClient默认使用TEXT_FILE_TYPE。因此，您必须将文件类型设置为二进制，如下所示：

client.setFileType(FTP.BINARY_FILE_TYPE);

Answer 3

您既没有刷新输出流也没有在finally块中关闭。试试吧。

Answer 4

try {

        Log.e("downloadFTP login : ", "Success");
        OutputStream desFileStream = new BufferedOutputStream( new FileOutputStream(desFilePath));
        Log.d(TAG,"FileOutputStream");
        status = mFTPClient.retrieveFile(srcFilePath, desFileStream);
        Log.d(TAG, "4");
        desFileStream.close();

        Log.e("downloadFTP status : ", "" + status);
        Log.d(TAG, "5");
        return status;
} catch (Exception e) {
    Log.d(TAG, "download failed");
}
return status;

}

如何使用FTPClient从FTP下载图像？

4 个答案: