Custom JavaFX WebView Protocol Handler - webview

Question

I am trying to write my own protocol handler for a JavaFX application that uses webview to access a single website. What I have done so far
My custom URLStreamHandlerFactory
public class MyURLStreamHandlerFactory implements URLStreamHandlerFactory {
public URLStreamHandler createURLStreamHandler(String protocol) {
System.out.println("Protocol: " + protocol);
if (protocol.equalsIgnoreCase("http") || protocol.equalsIgnoreCase("https")) {
return new MyURLStreamHandler();
} else {
return new URLStreamHandler() {
#Override
protected URLConnection openConnection(URL u) throws IOException {
return new URLConnection(u) {
#Override
public void connect() throws IOException {
}
};
}
};
}
}
}
My custom URLStreamHandler
public class MyURLStreamHandler extends java.net.URLStreamHandler{
protected HttpURLConnection openConnection(URL u){
MyURLConnection q = new MyURLConnection(u);
return q;
}
}
My custom HttpURLConnection
public class MyURLConnection extends HttpURLConnection {
static int defaultPort = 443;
InputStream in;
OutputStream out;
Socket s;
publicMyURLConnection(URL url) {
super(url);
try {
setRequestMethod("POST");
} catch (ProtocolException ex) {
ex.printStackTrace();
}
}
public void setRequestProperty(String name, String value){
super.setRequestProperty(name, value);
System.out.println("Namee: " + name);
System.out.println("Value: " + value);
}
public String getRequestProperty(String name){
System.out.println("GET REQUEST: ");
return super.getRequestProperty(name);
}
public OutputStream getOutputStream() throws IOException {
OutputStream os = super.getOutputStream();
System.out.println("Output: " + os);
return os;
}
public InputStream getInputStream() throws IOException {
InputStream is = super.getInputStream();
System.out.println("INout stream: " + is);
return is;
}
#Override
public void connect() throws IOException {
}
#Override
public void disconnect() {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public boolean usingProxy() {
throw new UnsupportedOperationException("Not supported yet.");
}
When I run the application I get the following error althouhg it seems to set some headers
Jul 08, 2013 11:09:04 AM com.sun.webpane.webkit.network.URLLoader doRun
WARNING: Unexpected error
java.net.UnknownServiceException: protocol doesn't support input
at java.net.URLConnection.getInputStream(URLConnection.java:839)
at qmed.QMedURLConnection.getInputStream(MyURLConnection.java:67)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:468)
at com.sun.webpane.webkit.network.URLLoader.receiveResponse(URLLoader.java:383)
at com.sun.webpane.webkit.network.URLLoader.doRun(URLLoader.java:142)
at com.sun.webpane.webkit.network.URLLoader.access$000(URLLoader.java:44)
at com.sun.webpane.webkit.network.URLLoader$1.run(URLLoader.java:106)
at com.sun.webpane.webkit.network.URLLoader$1.run(URLLoader.java:103)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.webpane.webkit.network.URLLoader.run(URLLoader.java:103)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)
All I want to do is get the response back for a given request and reads its binary data. I want the protocol to behave exactly the same way as the default one and only check the binary data of a given respone. What am I doing wrong?
The application is doing all shorts of URLConnections. Is it correct to use a HTTPURLConnection as my custom URLConnection class when the protocol is http or https and start a default URLStreamHandler when other protocols are used like I am doing in MyURLStreamHandlerFactory? Should I just extend the default URLConnection class in MYURLConnection to handle all protocols the same?
Any help would be much appreciated as this is a project threatening problem
Thank you

Answer 1

It might be that all you are missing is a setDoInput(true) or override getDoInput() and return true (that's what i did).
If that does not help check out my working solution:
MyURLStreamHandlerFactory:
import java.net.URLStreamHandler;
import java.net.URLStreamHandlerFactory;
public class MyURLStreamHandlerFactory implements URLStreamHandlerFactory
{
public URLStreamHandler createURLStreamHandler(String protocol)
{
if (protocol.equals("myapp"))
{
return new MyURLHandler();
}
return null;
}
}
Register Factory:
URL.setURLStreamHandlerFactory(new MyURLStreamHandlerFactory());
MyURLHandler :
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
public class MyURLHandler extends URLStreamHandler
{
#Override
protected URLConnection openConnection(URL url) throws IOException
{
return new MyURLConnection(url);
}
}
MyURLConnection:
import java.io.*;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.net.URLConnection;
/**
* Register a protocol handler for URLs like this: <code>myapp:///pics/sland.gif</code><br>
*/
public class MyURLConnection extends URLConnection
{
private byte[] data;
#Override
public void connect() throws IOException
{
if (connected)
{
return;
}
loadImage();
connected = true;
}
public String getHeaderField(String name)
{
if ("Content-Type".equalsIgnoreCase(name))
{
return getContentType();
}
else if ("Content-Length".equalsIgnoreCase(name))
{
return "" + getContentLength();
}
return null;
}
public String getContentType()
{
String fileName = getURL().getFile();
String ext = fileName.substring(fileName.lastIndexOf('.'));
return "image/" + ext; // TODO: switch based on file-type
}
public int getContentLength()
{
return data.length;
}
public long getContentLengthLong()
{
return data.length;
}
public boolean getDoInput()
{
return true;
}
public InputStream getInputStream() throws IOException
{
connect();
return new ByteArrayInputStream(data);
}
private void loadImage() throws IOException
{
if (data != null)
{
return;
}
try
{
int timeout = this.getConnectTimeout();
long start = System.currentTimeMillis();
URL url = getURL();
String imgPath = url.toExternalForm();
imgPath = imgPath.startsWith("myapp://") ? imgPath.substring("myapp://".length()) : imgPath.substring("myapp:".length()); // attention: triple '/' is reduced to a single '/'
// this is my own asynchronous image implementation
// instead of this part (including the following loop) you could do your own (synchronous) loading logic
MyImage img = MyApp.getImage(imgPath);
do
{
if (img.isFailed())
{
throw new IOException("Could not load image: " + getURL());
}
else if (!img.hasData())
{
long now = System.currentTimeMillis();
if (now - start > timeout)
{
throw new SocketTimeoutException();
}
Thread.sleep(100);
}
} while (!img.hasData());
data = img.getData();
}
catch (InterruptedException e)
{
e.printStackTrace();
}
}
public OutputStream getOutputStream() throws IOException
{
// this might be unnecessary - the whole method can probably be omitted for our purposes
return new ByteArrayOutputStream();
}
public java.security.Permission getPermission() throws IOException
{
return null; // we need no permissions to access this URL
}
}
Some parts of MyURLConnection might not be necessary for it to work, but like this it works for me.
Usage in JavaFX WebView:
<img src="myapp:///pics/image.png"/>
Note about permissions:
I used an applet with AllPermissions for my test with the above code.
In a Sandbox-Applet this won't work, as the setFactory permission is missing.

Answer 2

This is not directly related to the question asked, but might make the question itself obsolete.
With Java SE 6 Update 10 Java Applets support to access resources on any domain and port which is correctly set up with a crossdomain.xml.
With this the reason to register your own protocol might become obsolete, as you can access all resources that you need.
Another idea is: If you are trying to create a kind of network sniffer, why not directly use a network sniffer/analyzer program designed for such a task?

Answer 3

By activating Logging and Tracing in the Java Control-Panel your Java-Console will print all attempts and executed network calls including those from the WebView.
You can see all HTTP & HTTPS calls and their return-code + cookie data.
You might also see other protocol connections, but probably not any data sent over them.
This applies to Applets in a Browser.
If you need this in a different context maybe there is a way to activate the same options by passing command line parameters.