Launch options to force Java socket connections to localhost? - java

I'm trying to find a way to force any connection attempts a Jar makes to an external IP through my proxy server, which is running on localhost(Also a Java application).
Once the proxy server receives the connection it will open a connection with the external IP and begin routing the IO to and from the client/server.
I've been Googling this for 2 days, and I haven't had any luck, I believe I'm using the wrong terms in my search attempts.
If you've got any ideas, please let me know, I'll try anything.
Thanks in advance. - Sean.

If is that a "real" Proxy the you could specify the proxy to use using java system properties.
You have two alternatives:
Specify the proxy in the command line
Hardcode it into your app
Well you actually have three
Specify a .properties file, and read from there, and set it as System property ( which is pretty much option 2 but more dynamic )
From command line you'll use:
java -Dhttp.proxyHost=localhost -Dhttp.proxyPort=8080 -jar YourJar.jar
With that all the http connections you perform will go through localhost at port 8080
The second is add this at the main method of your program:
public static void main( String [] args ) {
System.setProperty("http.proxyHost", "localhost");
System.setProperty("http.proxyPort", "8080");
.....
}
Which does the same.
Finally loading from myapp.properties
public static void main( String [] args ) {
try { // there are cleaner ways of course
ResorceBundle bundle = ResourceBundle.getBundle("myapp");
System.setProperty("http.proxyHost", bundle.getString("proxy.server"));
System.setProperty("http.proxyPort", bundle.getString("proxy.port"));
} catch( MissingResourceException missingResourceException ){}
....
}
You just have to make sure myapp.properties is available from the classpath
More information about this functionality here

If you are asking about general (NOT HTTP / FTP specific!) proxying of Socket connections, then the simple answer is that it is not supported by Java.
When you configure a proxy for HTTP and FTP traffic, the proxying happens at the application protocol level. The Java-side proxy properties tell the URLConnection layer to connect to your designated proxy rather than the IP address from the URL your application is trying to connect to. The Java Socket level is unaware that this is happening. It just sees a requests to connect to the proxy.
This work because the HTTP and FTP protocols specifically support proxying. For instance, the first 'line' of an HTTP GET request message gives the full URL of the page that the client is requesting. If the GET request goes to a proxy, the proxy can figure out where is has to send it.
Looking at the problem of proxying at the Socket level, the first observation is that the standard Java class libraries don't support this. The second observation is that it is actually unimplementable ... unless you implement this as an alternative transport layer. The reason is that IP and TCP/IP simply do not support the notion of explicitly proxying or relaying messages / streams. And even if you did implement such a transport, it doesn't fit into the standard Socket model.
So, if you are really asking about proxying all of the network traffic for a Java application, this can only be implemented outside of the JVM; i.e. at the network transport level of the JVM's (physical or virtual) host operating system.

If it's HTTP traffic or FTP traffic, you could try the following system properties:
http.proxyHost (default: )
http.proxyPort (default: 80 if http.proxyHost specified)
http.nonProxyHosts (default:
See this link for details:
http://java.sun.com/docs/books/tutorial/networking/urls/_setProxy.html

Related

Soap Connection timed out in Java client but not in SOAPUI

I created a soap client with wsimport and a given wsdl. I also used SoapUI to test the service. Using SoapUI I had no problem but when using my Java client I get
java.net.ConnectException: Connection timed out: connect
The default values I have in the requestContext are as follows
com.sun.xml.internal.ws.connect.timeout=100000
javax.xml.ws.service.endpoint.address=[fully qualified domain name endpoint]
com.sun.xml.internal.ws.request.timeout=100000
javax.xml.ws.soap.http.soapaction.use=null
com.sun.xml.internal.ws.client.ContentNegotiation=none
javax.xml.ws.soap.http.soapaction.uri=null
I've tried increasing the timeout but it still doesn't connect.
Has anyone else had a similar problem?
As you mentioned the problem is of proxy, it has been answered in below links.
How to use an HTTP proxy in java
Proxy settings in a java program
If you are using proxy with authentication then you have set authenticator along with the proxy. This is answered here.
Authenticated HTTP proxy with Java
EDIT:
As correctly mentioned by William Burnham, you have set to set the properties before calling them.
Morever, I recommend you to clear the property soon after getting response using System.clearProperty(key) as the property is set for complete instance of jvm till it is restarted and hence can cause problems for other outgoing connections.
The problem was I was behind a proxy. I did different tests and found that using a web browser (or SoapUI) I was able to access the resource but from the command line it wasn't working.
After much searching, it was a simple fix: either passing the property as a jvm argument or manually setting it in the code with System.setProperty("java.net.useSystemProxies", "true"). The JVM wasn't using the proxy on its own.
EDIT
As I used wsimport I have a jax-ws client. It's important that proxy settings be configured prior to instantiantion.
ANOTHER EDIT
If by chance you're having problems and you're using an application server to make the soap request through the proxy, you may have to specify java.net.useSystemProxies=true (or similar) in the server's configuration--for example catalina.properties if using tomcat.

Java Equivilent of InternetSetOption

I am looking for a way to programmatically change Windows Internet Options (proxy settings more specific). I saw in C# there is a class called InternetSetOption which I believe will do want I need. I was wondering is there a Java equivalent?
If not is there anyway I can in Java change Windows network proxy settings INSTANTLY because changing registry would work but you need to reboot or restart explorer.exe which aren't options for this application.
I think I found what you are looking for here.
Here is some example code:
//Set the http proxy to webcache.mydomain.com:8080
System.setProperty("http.proxyHost", "webcache.mydomain.com");
System.setPropery("http.proxyPort", "8080");
// Next connection will be through proxy.
URL url = new URL("http://java.sun.com/");
InputStream in = url.openStream();
// Now, let's 'unset' the proxy.
System.setProperty("http.proxyHost", null);
// From now on http connections will be done directly.
Now,this works reasonably well, even if a bit cumbersome, but it can get tricky if your application is multi-threaded. Remember, system properties are “VM wide” settings, so all threads are affected. Which means that the code in one thread could, as a side effect, render the code in an other thread inoperative.
EDIT:
Here is some more specific examples:
Let's look at a few examples assuming we're trying to execute the main method of the GetURL class:
$ java -Dhttp.proxyHost=webcache.mydomain.com GetURL
All http connections will go through the proxy server at webcache.mydomain.com listening on port 80 (we didn't specify any port, so the default one is used).
$ java -Dhttp.proxyHost=webcache.mydomain.com -Dhttp.proxyPort=8080
-Dhttp.noProxyHosts=”localhost|host.mydomain.com” GetURL
In that second example, the proxy server will still be at webcache.mydomain.com, but this time listening on port 8080. Also, the proxy won't be used when connecting to either localhost or host.mydonain.com.
EDIT 2:
Perhaps something along these lines then:
System.setProperty( "http.proxyHost", "webcache.mydomain.com" );
System.setProperty( "http.proxyPort", "8080" );
System.setProperty( "https.proxyHost", "webcache.mydomain.com" );
System.setProperty( "https.proxyPort", "8080" );

Using Proxy server for Java application

So i have a java app that uses Google Analytics API to gather some info. I am putting this application to run in my oracle cloud managed server which has a firewall and blocks any web calls to work. So, they setup a proxy for me to use....I've never set up a proxy to work with a java application before, I've been reading at tutorials like this: http://docs.oracle.com/javase/1.5.0/docs/guide/net/proxies.html
And i have no idea how to set this up...anyone want to point me in the right direction?
You must tell your application that there's a proxy somewhere.
As the documentation says, you must set some properties in your virtual machine. You can do it programatically:
//Set the http proxy to webcache.mydomain.com:8080
System.setProperty("http.proxyHost", "webcache.mydomain.com");
System.setPropery("http.proxyPort", "8080");
// Next connection will be through proxy.
URL url = new URL("http://java.sun.com/");
InputStream in = url.openStream();
// Now, let's 'unset' the proxy.
System.clearProperty("http.proxyHost");
// From now on http connections will be done directly.
Or use https.proxy... if the connection is HTTPS.
Besides, if you have access to the application server start script, you could add those properties as VM properties with -Dhttp.proxyHost....
The solution in my case was to configure the JVM with a HTTPS proxy:
System.setProperty("https.proxyHost", "proxy");
System.setProperty("https.proxyPort", "3128");

How to deploy to specific URL

I have 2 grizzly applications I'd like to run side by side on different URLs on the same server. When I change my url from localhost to api.url.local for local debugging it throws a java.nio.channels.UnresolvedAddressException. Is there something I need to do in order for java to recognize another URL (ie - modify hosts file)? Or am I going in the wrong direction?
I'm currently on Windows but will be deploying to Linux. (If it were up to me, I'd run Linux)
public class Main {
public static final URI BASE_URI = getBaseURI();
private static URI getBaseURI() {
return UriBuilder.fromUri("http://localhost/").port(9998).build();
}
protected static HttpServer startServer() throws IOException {
ResourceConfig rc = new PackagesResourceConfig("com.my.package.api.resources");
rc.getFeatures()
.put(JSONConfiguration.FEATURE_POJO_MAPPING, true);
return GrizzlyServerFactory.createHttpServer(BASE_URI, rc);
}
public static void main(String[] args) throws IOException {
AnnotationConfigApplicationContext annotationCtx = new AnnotationConfigApplicationContext(Config.class);
HttpServer httpServer = startServer();
System.out.println(String.format("Jersey app started with WADL available at " + "%sapplication.wadl\nHit enter to stop it...", BASE_URI, BASE_URI));
System.in.read();
httpServer.stop();
}
}
Running two different applications under different urls on the same machine with one ip address is quite easy. But can require some setup depending on what you want to do.
My assumption is that you're doing this on your development machine. The biggest issue here is that the two servers require different port numbers.
Server #1
http://localhost:8080/
Server #2
http://localhost:8081/
If you want named instances instead. You will have to update your hosts file to point the named instance you want to your local machine. BUT, you'll still have to do separate ports per application.
Server #1
http://api.url.local:8080/
Server #2
http://api.url.local2:8081/
You will also have to update your tomcat (I'm assuming you're using tocmat) config. In the element, I believe you will have to update the 'name' attribute to be the name of your application's URL.
Friendly warning, if you are using the same IP Address, but different host names, SSL certificates will not work very well. Typically in that sort of setup you will need either a wildcard or unified communications certificate.
When you deploy to production, I would recommend using Apache HTTP Server as a proxy to your two applications and have two separate IP Address' unless you can use a SSL wildcard or a unified communications certificate.
This part of the answer is for if you wanted to run one application under two different URLs.
Proxy your application with a Apache Http Server instance and use mod_proxy to forward your two different server names or ip address' to the same Java instance.
My recommendation though, just run two instances of your application. Don't worry too much about resources, hardware is really cheep and worth a lot less then worrying about how to run one instance for two different sites.

SOAP connections through a proxy using URLEndpoint

I've had to update a previous java application that requests a SOAP response from an external web service. This service is outside our firewall which now requires us to go through a proxy instead of hitting the URL directly.
Currently the Java App uses URLEndpoint that takes a string for the URL. Usually when I am getting to a URL through a proxy I create a URL like so:
URL url = new URL("http", "theproxy.com", 5555, finalUrl);
The problem is URLEndpoint only takes a string for the url, I tried to convert URL to string using toExternalForm() but it malformed the URL.
Any ideas as to a way around this?
EDIT: I can't use System.setProperty as this runs with a whole heap of other Java applications in tomcat.
second edit: I can't set a system properties as it will override all other applications running on the server, I can't use jsocks as the proxy we run through squid proxy which does not support socks4/5
Any help appreciated.
That's not how proxy's work. The way a proxy works is that you take your normal URL:
http://example.com/service
and instead of looking up "example.com" and port 80, the message is sent to your proxy host instead (http://theproxy.com:5555).
Java has built in proxy handling using http.proxyHost and http.proxyPort System properties.
So in your case you would need to do:
System.setProperty("http.proxyHost", "theproxy.com");
System.setProperty("http.proxyPort", "5555");
Then your code should, ideally, "Just Work".
Here is a page documenting the proxy properties.
Use Apache HttpClient and do as show in this example.
About the URL constructor with individual proxy setting:
http://edn.embarcadero.com/article/29783
(sorry don't have privileges to comment)

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