How do I add query string to HttpMethod?

To send query string information in HTTP GET command you either using passing a simple string or an array of NameValuePair object into the HttpMethod‘s setQueryString() method. We also need to encode the parameter values before passing it to the method.

package org.kodejava.example.commons.httpclient;

import org.apache.commons.httpclient.*;
import org.apache.commons.httpclient.util.URIUtil;
import org.apache.commons.httpclient.methods.GetMethod;

import java.io.IOException;

public class SendingQueryParameter {
    public static void main(String[] args) {
        HttpClient client = new HttpClient();
        HttpMethod method = new GetMethod("http://www.kodejava.org/browse.php");

        try {
            //
            // Set query string information for accessing the page using a
            // simple string information.
            //
            method.setQueryString(URIUtil.encodeQuery("catid=47&page=1"));

            //
            // Other cleaner alternative is to use the NameValuePair object to
            // define the parameters for a HTTP GET method.
            //
            NameValuePair param1 = new NameValuePair("catid", URIUtil.encodeQuery("47"));
            NameValuePair param2 = new NameValuePair("page", URIUtil.encodeQuery("1"));
            NameValuePair[] params = new NameValuePair[] {param1, param2};
            method.setQueryString(params);

            client.executeMethod(method);
            
        } catch (URIException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            method.releaseConnection();
        }
    }
}

How do I setting a proxy for HttpClient?

In this example you will see how to configure proxy for the HttpClient.

package org.kodejava.example.commons.httpclient;

import org.apache.commons.httpclient.Credentials;
import org.apache.commons.httpclient.HostConfiguration;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.UsernamePasswordCredentials;
import org.apache.commons.httpclient.auth.AuthScope;
import org.apache.commons.httpclient.methods.GetMethod;

import java.io.IOException;

public class HttpGetProxy {
    private static final String PROXY_HOST = "proxy.host.com";
    private static final int PROXY_PORT = 8080;

    public static void main(String[] args) {
        HttpClient client = new HttpClient();
        HttpMethod method = new GetMethod("http://www.kodejava.org");

        HostConfiguration config = client.getHostConfiguration();
        config.setProxy(PROXY_HOST, PROXY_PORT);

        String username = "guest";
        String password = "s3cr3t";
        Credentials credentials = new UsernamePasswordCredentials(username, password);
        AuthScope authScope = new AuthScope(PROXY_HOST, PROXY_PORT);

        client.getState().setProxyCredentials(authScope, credentials);

        try {
            client.executeMethod(method);

            if (method.getStatusCode() == HttpStatus.SC_OK) {
                String response = method.getResponseBodyAsString();
                System.out.println("Response = " + response);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            method.releaseConnection();
        }
    }
}