How do I fix this UnknownHostException?

public static final String readURL(String url)throws Throwable
{
        try {
            InputStream in = (InputStream) fetch(url);
            byte[] bArr = readBytes(in);
            return new String(bArr);
        } catch (Throwable e) {
            throw e;
            }
}


public static final Object fetch(String address) throws MalformedURLException,IOException {
    URL url = new URL(address);
    Object content = url.getContent();
    return content;
}

I am behind a proxy and when I try

readURL("http://abc.com")

to access URL http://abc.com it throws java.net.UnknownHostException: I have:

<uses-permission android:name="android.permission.INTERNET" /> 

in manifest file.

Any quick solutions?