ObjectInputStream and Apache-Commons-Net FTPClient

Question

I'm trying to read a file from an FTP server accessed with the FTPClient class from the Apache Commons library, but method to get a file retrieveFile(remoteFileName, OutputStream) needs an OutputStream. I'm trying to get the object without first writing the file to the disk. Is there any way I can get the ObjectInputStream to read from an OutputStream? Or some other way that I haven't thought of yet?

EDIT: I've tried two ways:

public class FTPObjectReader
{
    public static Object read()
    {
        try
        {
            FTPClient ftp = new FTPClient(); 
            // Connect and stuff

            // Way one
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            ftp.retrieveFile("Data.dat", baos);
            baos.close();
            ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
            ObjectInputStream = new ObjectInputStream(bais);
            Object o = ois.readObject();

            // Way two
            ObjectInputStream ois = new ObjectInputStream(ftp.retrieveFileStream("Data.dat"));
            Object o = ois.readObject();
        }
    }
}

Stack trace:

java.io.StreamCorruptedException: invalid type code: 0A
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.readArray(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.defaultReadFields(Unknown Source)
    at java.io.ObjectInputStream.readSerialData(Unknown Source)
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.defaultReadFields(Unknown Source)
    at java.io.ObjectInputStream.readSerialData(Unknown Source)
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.defaultReadFields(Unknown Source)
    at java.io.ObjectInputStream.readSerialData(Unknown Source)
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.readObject(Unknown Source)
    at com.microgodrad.dev.Net.FTPObjectReader(FTPObjectReader.java:14)
    at com.microgodrad.dev.Net.main(Net.java:162) // File that calls this function

What object? Does the file you're retrieving really contain a serialized object? — user207421, Nov 20 '14 at 01:54
Yes, I used an ObjectOutputStream to write in the first place. — Qyriad, Nov 20 '14 at 02:04

score 0 · Answer 1 · answered Nov 20 '14 at 01:56

0

Use a ByteArrayOutputStream, then when it's closed wrap its byte array in a ByteArrayInputStream and wrap that in an ObjectInputStream.

answered Nov 20 '14 at 01:56

user207421

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When I perform `readObject()` on the ObjectInputStream I get a StreamCorruptedException. – Qyriad Nov 20 '14 at 02:20
Please post the entire exception, message, and stack trace, in your question; also the code you are now using. – user207421 Nov 20 '14 at 04:53
Edited original question with your requested information. – Qyriad Nov 20 '14 at 15:18
@MicroGodrad If the file doesn't start with 0xAC it can't be the result of serialization. This one starts with 0x0A, which is a line feed. Examine your assumptions. Or possibly you need to set binary mode on the FTP transfer. – user207421 Nov 20 '14 at 23:06

ObjectInputStream and Apache-Commons-Net FTPClient

1 Answers1