You need to encode the URI to replace illegal characters with legal encoded characters. If you first make a URL (so you don’t have to do the parsing yourself) and then make a URI using the five-argument constructor, then the constructor will do the encoding for you.
import java.net.*;
public class Test {
public static void main(String[] args) {
String myURL = "http://finance.yahoo.com/q/h?s=^IXIC";
try {
URL url = new URL(myURL);
String nullFragment = null;
URI uri = new URI(url.getProtocol(), url.getHost(), url.getPath(), url.getQuery(), nullFragment);
System.out.println("URI " + uri.toString() + " is OK");
} catch (MalformedURLException e) {
System.out.println("URL " + myURL + " is a malformed URL");
} catch (URISyntaxException e) {
System.out.println("URI " + myURL + " is a malformed URL");
}
}
}