URLs and URIs - Java Network Programming - page 153

The output of this is what you actually want:
https: //www.google.com/search?hl=en&as_q=Java&as_epq=I/O
In this case, you could have skipped encoding several of the constant strings such as
“Java” because you know from inspection that they don't contain any characters that
need to be encoded. However, in general, these values will be variables, not constants;
and you'll need to encode each piece to be safe.
Example 5-8 is a QueryString class that uses URLEncoder to encode successive name
and value pairs in a Java object, which will be used for sending data to server-side
programs. To add name-value pairs, call the add() method, which takes two strings as
arguments and encodes them. The getQuery() method returns the accumulated list of
encoded name-value pairs.
Example 5-8. The QueryString class
import java.io.UnsupportedEncodingException ;
import java.net.URLEncoder ;
public class QueryString {
private StringBuilder query = new StringBuilder ();
public QueryString () {
}
public synchronized void add ( String name , String value ) {
query . append ( '&' );
encode ( name , value );
}
private synchronized void encode ( String name , String value ) {
try {
query . append ( URLEncoder . encode ( name , "UTF-8" ));
query . append ( '=' );
query . append ( URLEncoder . encode ( value , "UTF-8" ));
} catch ( UnsupportedEncodingException ex ) {
throw new RuntimeException ( "Broken VM does not support UTF-8" );
}
}
public synchronized String getQuery () {
return query . toString ();
}
@Override
public String toString () {
return getQuery ();
}
}