How to upload a file using Java HttpClient library

Question

I want to write Java application that will upload a file to the Apache server with PHP. The Java code uses Jakarta HttpClient library version 4.0 beta2:

import java.io.File;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.FileEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.util.EntityUtils;


public class PostFile {
  public static void main(String[] args) throws Exception {
    HttpClient httpclient = new DefaultHttpClient();
    httpclient.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);

    HttpPost httppost = new HttpPost("http://localhost:9002/upload.php");
    File file = new File("c:/TRASH/zaba_1.jpg");

    FileEntity reqEntity = new FileEntity(file, "binary/octet-stream");

    httppost.setEntity(reqEntity);
    reqEntity.setContentType("binary/octet-stream");
    System.out.println("executing request " + httppost.getRequestLine());
    HttpResponse response = httpclient.execute(httppost);
    HttpEntity resEntity = response.getEntity();

    System.out.println(response.getStatusLine());
    if (resEntity != null) {
      System.out.println(EntityUtils.toString(resEntity));
    }
    if (resEntity != null) {
      resEntity.consumeContent();
    }

    httpclient.getConnectionManager().shutdown();
  }
}

The PHP file upload.php is very simple:

<?php
if (is_uploaded_file($_FILES['userfile']['tmp_name'])) {
  echo "File ". $_FILES['userfile']['name'] ." uploaded successfully.\n";
  move_uploaded_file ($_FILES['userfile'] ['tmp_name'], $_FILES['userfile'] ['name']);
} else {
  echo "Possible file upload attack: ";
  echo "filename '". $_FILES['userfile']['tmp_name'] . "'.";
  print_r($_FILES);
}
?>

Reading the response I get the following result:

executing request POST http://localhost:9002/upload.php HTTP/1.1

HTTP/1.1 200 OK
Possible file upload attack: filename ''.
Array
(
)

So the request was successful, I was able to communicate with server, however PHP didn't notice the file - the method is_uploaded_file returned false and $_FILES variable is empty. I have no idea why this might happend. I have tracked HTTP response and request and they look ok:
request is:

POST /upload.php HTTP/1.1
Content-Length: 13091
Content-Type: binary/octet-stream
Host: localhost:9002
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.0-beta2 (java 1.5)
Expect: 100-Continue

˙Ř˙ŕ..... the rest of the binary file...

and response:

HTTP/1.1 100 Continue

HTTP/1.1 200 OK
Date: Wed, 01 Jul 2009 06:51:57 GMT
Server: Apache/2.2.8 (Win32) DAV/2 mod_ssl/2.2.8 OpenSSL/0.9.8g mod_autoindex_color PHP/5.2.5 mod_jk/1.2.26
X-Powered-By: PHP/5.2.5
Content-Length: 51
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: text/html

Possible file upload attack: filename ''.Array
(
)

I was testing this both on the local windows xp with xampp and remote Linux server. I have also tried to use previous version of HttpClient - version 3.1 - and the result was even more unclear, is_uploaded_file returned false, however $_FILES array was filled with proper data.

Answer 1

Aah you just need to add a name parameter in the

FileBody constructor. ContentBody cbFile = new FileBody(file, "image/jpeg", "FILE_NAME");

Hope it helps.

Answer 2

There is my working solution for sending image with post, using apache http libraries (very important here is boundary add It won't work without it in my connection):

            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
            byte[] imageBytes = baos.toByteArray();

            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(StaticData.AMBAJE_SERVER_URL + StaticData.AMBAJE_ADD_AMBAJ_TO_GROUP);

            String boundary = "-------------" + System.currentTimeMillis();

            httpPost.setHeader("Content-type", "multipart/form-data; boundary="+boundary);

            ByteArrayBody bab = new ByteArrayBody(imageBytes, "pic.png");
            StringBody sbOwner = new StringBody(StaticData.loggedUserId, ContentType.TEXT_PLAIN);
            StringBody sbGroup = new StringBody("group", ContentType.TEXT_PLAIN);

            HttpEntity entity = MultipartEntityBuilder.create()
                    .setMode(HttpMultipartMode.BROWSER_COMPATIBLE)
                    .setBoundary(boundary)
                    .addPart("group", sbGroup)
                    .addPart("owner", sbOwner)
                    .addPart("image", bab)
                    .build();

            httpPost.setEntity(entity);

            try {
                HttpResponse response = httpclient.execute(httpPost);
                ...then reading response

Answer 3

The correct way will be to use multipart POST method. See here for example code for the client.

For PHP there are many tutorials available. This is the first I've found. I recommend that you test the PHP code first using an html client and then try the java client.

Answer 4

A newer version example is here.

Below is a copy of the original code:

/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */
package org.apache.http.examples.entity.mime;

import java.io.File;

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

/**
 * Example how to use multipart/form encoded POST request.
 */
public class ClientMultipartFormPost {

    public static void main(String[] args) throws Exception {
        if (args.length != 1)  {
            System.out.println("File path not given");
            System.exit(1);
        }
        CloseableHttpClient httpclient = HttpClients.createDefault();
        try {
            HttpPost httppost = new HttpPost("http://localhost:8080" +
                    "/servlets-examples/servlet/RequestInfoExample");

            FileBody bin = new FileBody(new File(args[0]));
            StringBody comment = new StringBody("A binary file of some kind", ContentType.TEXT_PLAIN);

            HttpEntity reqEntity = MultipartEntityBuilder.create()
                    .addPart("bin", bin)
                    .addPart("comment", comment)
                    .build();


            httppost.setEntity(reqEntity);

            System.out.println("executing request " + httppost.getRequestLine());
            CloseableHttpResponse response = httpclient.execute(httppost);
            try {
                System.out.println("----------------------------------------");
                System.out.println(response.getStatusLine());
                HttpEntity resEntity = response.getEntity();
                if (resEntity != null) {
                    System.out.println("Response content length: " + resEntity.getContentLength());
                }
                EntityUtils.consume(resEntity);
            } finally {
                response.close();
            }
        } finally {
            httpclient.close();
        }
    }

}

Answer 5

I ran into the same problem and found out that the file name is required for httpclient 4.x to be working with PHP backend. It was not the case for httpclient 3.x.

So my solution is to add a name parameter in the FileBody constructor. ContentBody cbFile = new FileBody(file, "image/jpeg", "FILE_NAME");

Hope it helps.

Answer 6

If you are testing this on your local WAMP you might need to set up the temporary folder for file uploads. You can do this in your PHP.ini file:

upload_tmp_dir = "c:\mypath\mytempfolder\"

You will need to grant permissions on the folder to allow the upload to take place - the permission you need to grant vary based on your operating system.