java - FTPClient 如何解决 org.apache.commons.net.io.CopyStreamException : IOException caught while copying

Question

我正在尝试使用 Apache Commons Net FTPSClient 将带有 Java 应用程序的 .zip 文件上传到 FTP 服务器。

<pre><code>import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPSClient;

public class FTPUploader {
    /**
     * Zips the source file first and then uploads it to the ftp server
     * @param source - The file to be uploaded
     * @param target - The file on the ftp server to upload to
     */
    public static void upload(String source, String target){
        BufferedInputStream stream = null;
        File zippedFile = new File("/temp/"+UUID.randomUUID()+".zip");
        File targetFile = new File(target);
        FTPSClient client = new FTPSClient();
        System.out.println("[FTPClient] Starting Upload of "+source+" to "+target);
        try {
            //Establish connection to FTP Server
            client.connect("localhost");
            client.login("user", "password"); //changed
            client.setFileType(FTP.BINARY_FILE_TYPE);
            client.enterLocalPassiveMode();
            client.execPBSZ(0);
            client.execPROT("P");
            //Get the original File
            File file = new File(source);
            //Zip the file before uploading
            if(file.isDirectory()){
                ZipUtil.zipDirectory(source, zippedFile.getPath());
            }
            else{
                ZipUtil.zipFile(source, zippedFile.getPath());
            }
            //Go to the directory on the ftp server
            String directoryPath = targetFile.getParentFile().getPath();
            //If it doesn't exist create it
            if(!client.changeWorkingDirectory(directoryPath)){
                client.makeDirectory(directoryPath);
                client.changeWorkingDirectory(directoryPath);
            }
            //Create an InputStream of the zipped file to be uploaded
            stream = new BufferedInputStream(new FileInputStream(zippedFile));
            //Store zipped file to server
            if(client.storeFile(targetFile.getName(), stream)){
                System.out.println("[FTPClient] Done!");
            }
            else{
                System.out.println("[FTPClient] Upload failed: "+client.getReplyString());
            }
            //Finish up
            client.logout();
        } catch (IOException e) {
            System.out.println("[FTPClient] Error! Last Reply: "+client.getReplyString());
            e.printStackTrace();
        } finally {
            try {
                if (stream != null) {
                    stream.close();
                }
                client.disconnect();
                zippedFile.delete();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

org.apache.commons.net.io.CopyStreamException: IOException caught while copying.
    at org.apache.commons.net.io.Util.copyStream(Util.java:136)
    at org.apache.commons.net.ftp.FTPClient._storeFile(FTPClient.java:675)
    at org.apache.commons.net.ftp.FTPClient.__storeFile(FTPClient.java:639)
    at org.apache.commons.net.ftp.FTPClient.storeFile(FTPClient.java:2030)
    ... 2 more
 Caused by: java.net.SocketException: Broken pipe (Write failed)
    at java.net.SocketOutputStream.socketWrite0(Native Method)
    at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111)
    at java.net.SocketOutputStream.write(SocketOutputStream.java:155)
    at sun.security.ssl.OutputRecord.writeBuffer(OutputRecord.java:431)
    at sun.security.ssl.OutputRecord.write(OutputRecord.java:417)
    at sun.security.ssl.SSLSocketImpl.writeRecordInternal(SSLSocketImpl.java:886)
    at sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:857)
    at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:123)
    at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
    at java.io.BufferedOutputStream.write(BufferedOutputStream.java:126)
    at org.apache.commons.net.io.Util.copyStream(Util.java:124)
    ... 5 more</code></pre>

我检查的事情:

• 与 FTP 服务器的连接正常
• 登录成功
• FTP 服务器上的目录已成功创建
• 在 FTP 服务器上创建具有正确名称的空 .zip 文件
• 远程目录的权限为 755(可以写入)
• 本地和远程文件路径均正确且本地文件存在

有人知道如何解决这个错误吗？

Answer 1

该问题是由 FTP 服务器引起的。它有一个设置，强制 FTP 客户端在数据通道上重用来自控制 channel 的 SSL session ，而 apache commons FTP 客户端显然不会这样做。使用“TLSOptions NoSessionReuseRequired”禁用服务器上的要求解决了该问题。

值得注意的是，该要求似乎有安全背景，因为当不需要使用相同的 SSL session 时，数据通道可能会被劫持。请参阅这个答案:https://stackoverflow.com/a/32404418/10173457