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

For those having a hard time implementing the accepted answer (which requires org.apache.http.entity.mime.MultipartEntity) you may be using org.apache.httpcomponents 4.2.* In this case, you have to explicitly install httpmime dependency, in my case:

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpmime</artifactId>
    <version>4.2.5</version>
</dependency>

Answer 2

I knew I am late to the party but below is the correct way to deal with this, the key is to use InputStreamBody in place of FileBody to upload multi-part file.

   try {
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost postRequest = new HttpPost("https://someserver.com/api/path/");
        postRequest.addHeader("Authorization",authHeader);
        //don't set the content type here            
        //postRequest.addHeader("Content-Type","multipart/form-data");
        MultipartEntity reqEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);


        File file = new File(filePath);
        FileInputStream fileInputStream = new FileInputStream(file);
        reqEntity.addPart("parm-name", new InputStreamBody(fileInputStream,"image/jpeg","file_name.jpg"));

        postRequest.setEntity(reqEntity);
        HttpResponse response = httpclient.execute(postRequest);

        }catch(Exception e) {
            Log.e("URISyntaxException", e.toString());
   }

Answer 3

An update for those trying to use MultipartEntity...

org.apache.http.entity.mime.MultipartEntity is deprecated in 4.3.1.

You can use MultipartEntityBuilder to create the HttpEntity object.

File file = new File();

HttpEntity httpEntity = MultipartEntityBuilder.create()
    .addBinaryBody("file", file, ContentType.create("image/jpeg"), file.getName())
    .build();

For Maven users the class is available in the following dependency (almost the same as fervisa's answer, just with a later version).

<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpmime</artifactId>
  <version>4.3.1</version>
</dependency>

Answer 4

Ok, the Java code I used was wrong, here comes the right Java class:

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.mime.MultipartEntity;
import org.apache.http.entity.mime.content.ContentBody;
import org.apache.http.entity.mime.content.FileBody;
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:9001/upload.php");
    File file = new File("c:/TRASH/zaba_1.jpg");

    MultipartEntity mpEntity = new MultipartEntity();
    ContentBody cbFile = new FileBody(file, "image/jpeg");
    mpEntity.addPart("userfile", cbFile);


    httppost.setEntity(mpEntity);
    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();
  }
}

note using MultipartEntity.