Upload an image.

[dudejonne]

Okay, I got an applet from a friend working, the applet makes an Image called image. Is there a way to upload the image to my server like an image uploader like imageshack.us. Is this possible through Java? Or maybe can I send the Image image from Java to php?

[travishein]

have you tried commons-httpclient, a Java HTTP client library, have your applet use this to invoke a POST to your server, and on the server side have a PHP handler receive the post body and extract the image and do what ever you do with it then.

[dudejonne]

Thanks, but I really don't know how to do that, could you help me out a little?

I try to send an Image called image to php and then let php upload it to my server, just like imageshack.us does (so it returns a link and the people can view the image). But the only difference is I don't want to let the user browse his files, I just want to upload the image out of the Java applet.

[dudejonne]

bump it up a little

[travishein]

well, you have the sources for the applet ? as my suggestion to use the commons-httpclient to POST the image as the stream would require you to get into the applet. Also likely you would need to have some experience with building the applet again, e.g. Ant build script. And then to have the modified code .jar file deployed to your web server, but you mentioned applet was already working, so this part has been done before. I just keep forgetting to actually upload my modified jar file to the server and pull out hair wondering why the changes aren't working :). Andthe commons-httpclient will require adding their jar file and dependencies to the applet code base class:

commons-httpclient.jar
commons-codec.jar
commons-logging.jar

so, to use a custom HTTP POST, there are standards for multi-part form data content types, and RFC 2045 (MIME) encoding of the contents. but if you are using a custom PHP receiver on the server side, we might just as well stream the raw image data, and perhaps set a HTTP header for the file name we want the server to save it as.

for example, once you have the Image object

/**
 *Created on Oct 29, 2009
 */

import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.io.IOException;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;

import javax.imageio.ImageIO;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.InputStreamRequestEntity;
import org.apache.commons.httpclient.methods.PostMethod;


public class ImageTest {

  public void theProgram() {
    
    // how ever you get your image object, like if its generated, or drawn.
    BufferedImage bimg = new BufferedImage(100, 100, BufferedImage.TYPE_3BYTE_BGR);

    // now that have the image, do the upload to the server.
    try {
      int statusCode =  uploadImage(bimg, "http://your.server.example.com/uploadImageHandler", "myImage.png");
      System.out.println("HTTP result code: " + statusCode); 
    } 
    catch (IOException ex) {
      // failed to upload 
    }
  }

  /**
   * uses commons-httpclient to send it to your server
   * @param bimg an image object to be uploaded
   * @param uploadUrl the HTTP url to our server-side handler to receive the image stream and do what ever with it.
   * @param targetFileName, the name we want this image saved as, such as in the uploads folder on the server.
   * @return
   */
  public int uploadImage(RenderedImage bimg, String uploadUrl, String targetFileName) throws IOException {
    int statusCode = HttpStatus.SC_INTERNAL_SERVER_ERROR;
    
    HttpClient httpClient = new HttpClient();
    PostMethod postMethod = new PostMethod(uploadUrl);
    
    PipedOutputStream pout = new PipedOutputStream();
    PipedInputStream pin = new PipedInputStream(pout);
    
    // set any other request headers  
    postMethod.setRequestHeader("Content-Type", "image/png");
    
    // some header we invent to have the server able to save this stream to a file
    // the server-side handler will need to look for this.
    postMethod.setRequestHeader("Target-File-Name", targetFileName);
    postMethod.setRequestEntity(new InputStreamRequestEntity(pin));
    ImageIO.write(bimg, "png", pout);
   
    try {
      statusCode = httpClient.executeMethod(postMethod);
    }
    finally {
      postMethod.releaseConnection();
    }
    
    return statusCode;
  }
}

see also: Image IO


I'ts been a while since I have used PHP on the server side, but you would need to have a handler to receive this post, look for the Target-File-Name HTTP header we stuffed into there, and then open the file for writing in some uploads folder or something, and then begin writing what ever it reads from the request into this file, until the end of the request.

I don't like not setting the content length on the upload ahead of time, likely would be more robust, but unless we did some kind of write the image to a file on the applet side first, we can't know how large the rendered file would be until after its renderer.

Hope thats helpful.

[dudejonne]

ImageGrabber.java:14: package org.apache.commons.httpclient does not exist
import org.apache.commons.httpclient.HttpClient;
^
ImageGrabber.java:15: package org.apache.commons.httpclient does not exist
import org.apache.commons.httpclient.HttpStatus;
^
ImageGrabber.java:16: package org.apache.commons.httpclient.methods does not exi
st
import org.apache.commons.httpclient.methods.InputStreamR equestEntity;
^
ImageGrabber.java:17: package org.apache.commons.httpclient.methods does not exi
st
import org.apache.commons.httpclient.methods.PostMethod;
^
ImageGrabber.java:99: non-static method uploadImage(java.awt.image.RenderedImage
,java.lang.String,java.lang.String) cannot be referenced from a static context
int statusCode = uploadImage(bimg, "C:/Documents and Settings/Jonneh/Bure
aublad/Server/", "myImage.png");
^
ImageGrabber.java:109: cannot find symbol
symbol : variable bimgt
location: class ImageGrabber
new Viewer(bimgt);
^
ImageGrabber.java:117: cannot find symbol
symbol : variable HttpStatus
location: class ImageGrabber
int statusCode = HttpStatus.SC_INTERNAL_SERVER_ERROR;
^
ImageGrabber.java:119: cannot find symbol
symbol : class HttpClient
location: class ImageGrabber
HttpClient httpClient = new HttpClient();
^
ImageGrabber.java:119: cannot find symbol
symbol : class HttpClient
location: class ImageGrabber
HttpClient httpClient = new HttpClient();
^
ImageGrabber.java:120: cannot find symbol
symbol : class PostMethod
location: class ImageGrabber
PostMethod postMethod = new PostMethod(uploadUrl);
^
ImageGrabber.java:120: cannot find symbol
symbol : class PostMethod
location: class ImageGrabber
PostMethod postMethod = new PostMethod(uploadUrl);
^
ImageGrabber.java:131: cannot find symbol
symbol : class InputStreamRequestEntity
location: class ImageGrabber
postMethod.setRequestEntity(new InputStreamRequestEntity(pin));
^
12 errors



I did imported that stuf, should I download something extra or something to get it work? Also, I don't care about the file size or anything, I just want to store the image on my server or send it to php the easiest way. Thanks!

[dudejonne]

I got another code working:

try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(bimg, "jpeg", baos);
byte[] data = baos.toByteArray();
URL u = new URL(here goes the url);
HttpURLConnection out = (HttpURLConnection) u.openConnection();
out.setRequestMethod("POST");
out.setDoOutput(true);
out.setDoInput(true);
out.setRequestProperty("Content-Type", "image/png");
out.setRequestProperty("Content-Length", Integer.toString(data.length));
out.connect();
OutputStream outs = out.getOutputStream();
outs.write(data);
outs.flush();
outs.close();
BufferedReader blah = new BufferedReader(new InputStreamReader(out.getInputStream()));
String blahS;
while((blahS = blah.readLine()) != null)
System.out.println(blahS);
} catch (Exception e) {
e.printStackTrace();
}

But it gives this error:

java.lang.ClassCastExeption: sun.net. www .protocol.file.FileURLConnection cannot be cast to java.net.HttpURLConnector

Who knows how to fix it?

[travishein]

I have been doing more thinking, if this is for an applet in a browser, perhaps the commons-httpclient way is a bit too heavyweight. so before i send you down a fox hole, see the discussion for a HttpUrlConnection apprach later on in this reply

so. if we did want to still use the commons-httpclient, we need
http://mirror.csclub.uwaterloo.ca/ap...client-3.1.zip
I haven't used their current 4.0 yet, its pretty new. so i'd stick with the 3.1 for now.

and its dependencies
http://apache.mirror.iweb.ca/commons...-1.1.1-bin.zip
http://apache.parentinginformed.com/...ec-1.4-bin.zip

After you download these (3) pieces, each will contain a .jar file. we need to have that jar file used on the javac path, AND the applet runtime path. like if you use javac before on its own, now would need to javac -classpath commons-httpclient-3.1.jar:commons-logging-1.1.1.jar:commons-codec-1.4.jar

or something, how ever your build environment finds and staples lib files into the compile path.

and for deployment the applet tag needs to have these 3 jar files also added to its codebase path.


The alternate approach using HttpUrlConnection works entirely with what's already bundled into the Java runtime, likely more convenient in your situation.

A good general example of how this works can be found here

and adapted their example,

  /**
   * uses HttpUrlRequest to send it to your server
   * @param bimg an image object to be uploaded
   * @param uploadUrl the HTTP url to our server-side handler to receive the image stream and do what ever with it.
   * @param targetFileName, the name we want this image saved as, such as in the uploads folder on the server.
   * @return
   */
  public int uploadHttpUrlConnectionImage(RenderedImage bimg, String uploadUrl, String targetFileName) throws IOException {
    URL url;
    HttpURLConnection connection = null;  
    try {
      //Create connection
      url = new URL(uploadUrl);
      connection = (HttpURLConnection)url.openConnection();
      connection.setRequestMethod("POST");
      connection.setRequestProperty("Content-Type",  "image/png");
      connection.setRequestProperty("Target-File-Name", targetFileName);  
      
      
      connection.setUseCaches (false);
      connection.setDoInput(true);
      connection.setDoOutput(true);

      //Send request
      DataOutputStream wr = new DataOutputStream (
                  connection.getOutputStream ());
      
      ImageIO.write(bimg, "png", wr);
      wr.flush ();
      wr.close ();

      //Get Response  
      InputStream is = connection.getInputStream();
      BufferedReader rd = new BufferedReader(new InputStreamReader(is));
      String line;
      StringBuffer response = new StringBuffer(); 
      while((line = rd.readLine()) != null) {
        response.append(line);
        response.append('\r');
      }
      rd.close();
      
      return connection.getResponseCode();

    } catch (Exception e) {

      e.printStackTrace();
      return 500;

    } finally {

      if(connection != null) {
        connection.disconnect(); 
      }
    }
  }

all this stuff is in the java.io package, so addding imports and compiling won't require those 3 jar files for the commons-httplclient thing.

[dudejonne]

Thanks for your reply, I'll try it out later.
But isn't it much simpler to do something like this:
ImageIO.write(bufferedImage,"jpg",file);
?
Wouldn't that store a buffered image as jpg on my server? If the applet was on my server too?

[dudejonne]

Wait, now I have an applet that stores the image in the same folder as the applet. If I would upload the applet to my server, would it work too?

[travishein]

Yea, i guess if you ran the applet in a web browser on the server, as a user with the write permission to a folder in the server, and if the saving to a local file is simpler and it does work, then in that case, it would get the file to the 'server' , since its the same file system. Usually applets need to be signed to allow them to have access to the local file system of the system that is running the browser client. but in your special case, that's also the server. I've been thinking in client/server land so long I never would have considered the simple special case of client is the server. :)

[dudejonne]

Ok thnx, now I only need to get the applet working.

[dudejonne]

okay bummer..
ImageIO.write(bufferedImage,"jpg",file);
isn't working.
Anyone has a (simple? :) ) other solution?

[jfileupload]

To avoid developing from scratch you could use JImageUpload. It's an applet allows to preview and upload images. It can upload overs HTTP or FTP. Also, if you need to scale image before upload then you can use JImageFilter add-on. You can try out them from jfileupload.com web site.

Hope it could help.