system.setproperty problem

[hsn]

hello everyone.
i am trying to use the system.setproperty to set the proxy in my computer.

public static void main(String[] args) {
 
    // TODO Auto-generated method stub
 
 
        System.setProperty("http.proxyHost","192.222.222.2");
        System.setProperty("http.proxyPort","808");
        System.setProperty("http.nonProxyHosts","yahoo.com");
 
        detect2();
 
 
 
    }
 
 
 
    public static void detect2() {
 
        try {
            //System.setProperty("java.net.useSystemProxies","true");
 
            List l = ProxySelector.getDefault().select(new URI("http://www.yahoo.com/"));
 
            for (Iterator iter = l.iterator(); iter.hasNext(); ) {
            Proxy proxy = (Proxy) iter.next();
            System.out.println("proxy type : " + proxy.type());
            InetSocketAddress addr = (InetSocketAddress)
            proxy.address();
            if(addr == null) {
 
            System.out.println("No Proxy");
            } else {
 
            System.out.println("proxy hostname : " +addr.getHostName());
            System.out.println("proxy port : " +addr.getPort());
 
            }
 
            }
 
        } 
        catch (Exception e) {
            e.printStackTrace();
        }
 
 
 
 
 
    }
 
    public static void detect(String location)
 
    {
 
        String proxyHost;
 
        int proxyPort;
 
        try {
 
            ProxyInfo info[] = ProxyService.getProxyInfo(new URL(location));
 
            if(info != null && info.length>0)
 
            {
 
            proxyHost = info[0].getHost();
 
            proxyPort = info[0].getPort();
 
            System.out.println("PROXY = " + proxyHost + ":" + proxyPort);
 
            }
 
        }
        catch (Exception ex) {
            System.err.println("could not retrieve proxy configuration, attempting direct connection." + ex);
        }
 
    }
 
 

IF YOU run this code you will find that the proxy has been changed from direct to http and the host and the port will be as it is specified in the code.
after you run it the first time please comment the following line of code

System.setProperty("http.proxyHost","192.222.222.2");
System.setProperty("http.proxyPort","808");
System.setProperty("http.nonProxyHosts","yahoo.com");
 

and run the program again.
you will find that the proxy returned to Direct.

i need to know how can i set save the changes i added to system.property so all the browsers will use this proxy.

kind regards
hsn

[hsn]

if someone else knows who to set the proxy in the computer so it could be used by the browsers in a different way. please help

hsn

[JosAH]

System properties aren't persistent; i.e. all properties are gone when the JVM has stopped. You can set your properties on the command line:
-Dkey=value associates key with value as a system property before your main() is run.

kind regards,

Jos

[hsn]

hello Jos.
i have never used the terminal to run java code. after u posted you reply, i search online and i learned it.
after compiling the java code i enter this command

java MainTest -D http.proxyHost= "yahoo.com" -D http.proxyPort=999

is this the correct syntax??

hsn

[JosAH]

Put those -Dkey=value parameter(s) at the start (following 'java'), otherwise they are just arguments for your main() method.

kind regards,

Jos

[hsn]

hello Jos.
i have tried your advice. i was able to use -D and the data was changed.
but then when i try to run the program again just to make sure that the data were saved, but the proxy was returned to Direct.

[JosAH]

@hsn
Reread my reply #3: properties aren't persisten. When your program stops running all those properties are gone.

kind regards,

Jos

[hsn]

thanks Jos. at least now i know how useful are setproperties