Common HTTPclient and proxy

Question

I am using apache's common httpclient library. Is it possible to make HTTP request over proxy? More specific, I need to use proxy list for multithreaded POST requests (right now I am testing with single threaded GET requests).

I tried to use:

        httpclient.getHostConfiguration().setProxy("67.177.104.230", 58720);

I get errors with that code:

21.03.2012. 20:49:17 org.apache.commons.httpclient.HttpMethodDirector executeWithRetry
INFO: I/O exception (java.net.ConnectException) caught when processing request: Connection refused: connect
21.03.2012. 20:49:17 org.apache.commons.httpclient.HttpMethodDirector executeWithRetry
INFO: Retrying request
21.03.2012. 20:49:19 org.apache.commons.httpclient.HttpMethodDirector executeWithRetry
INFO: I/O exception (java.net.ConnectException) caught when processing request: Connection refused: connect
21.03.2012. 20:49:19 org.apache.commons.httpclient.HttpMethodDirector executeWithRetry
INFO: Retrying request
21.03.2012. 20:49:21 org.apache.commons.httpclient.HttpMethodDirector executeWithRetry
INFO: I/O exception (java.net.ConnectException) caught when processing request: Connection refused: connect
21.03.2012. 20:49:21 org.apache.commons.httpclient.HttpMethodDirector executeWithRetry
INFO: Retrying request
org.apache.commons.httpclient.ProtocolException: The server xxxxx failed to respond with a valid HTTP response
    at org.apache.commons.httpclient.HttpMethodBase.readStatusLine(HttpMethodBase.java:1846)
    at org.apache.commons.httpclient.HttpMethodBase.readResponse(HttpMethodBase.java:1590)
    at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:995)
    at org.apache.commons.httpclient.ConnectMethod.execute(ConnectMethod.java:144)
    at org.apache.commons.httpclient.HttpMethodDirector.executeConnect(HttpMethodDirector.java:495)
    at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:390)
    at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:170)
    at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:396)
    at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:324)
    at test.main(test.java:42)

When I remove that line, everything runs fine as expected.

Answer 1

For httpclient 4.1.x you can set the proxy like this (taken from this example):

    HttpHost proxy = new HttpHost("127.0.0.1", 8080, "http");

    DefaultHttpClient httpclient = new DefaultHttpClient();
    try {
        httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);

        HttpHost target = new HttpHost("issues.apache.org", 443, "https");
        HttpGet req = new HttpGet("/");

        System.out.println("executing request to " + target + " via " + proxy);
        HttpResponse rsp = httpclient.execute(target, req);
        ...
    } finally {
        // When HttpClient instance is no longer needed,
        // shut down the connection manager to ensure
        // immediate deallocation of all system resources
        httpclient.getConnectionManager().shutdown();
    }

Answer 2

Here is how to do that with the last version of HTTPClient (4.3.4)

    CloseableHttpClient httpclient = HttpClients.createDefault();
    try {
        HttpHost target = new HttpHost("localhost", 443, "https");
        HttpHost proxy = new HttpHost("127.0.0.1", 8080, "http");

        RequestConfig config = RequestConfig.custom()
                .setProxy(proxy)
                .build();
        HttpGet request = new HttpGet("/");
        request.setConfig(config);

        System.out.println("Executing request " + request.getRequestLine() + " to " + target + " via " + proxy);

        CloseableHttpResponse response = httpclient.execute(target, request);
        try {
            System.out.println("----------------------------------------");
            System.out.println(response.getStatusLine());
            EntityUtils.consume(response.getEntity());
        } finally {
            response.close();
        }
    } finally {
        httpclient.close();
    }

Answer 3

Starting from Apache HTTPComponents 4.3.x HttpClientBuilder class sets the proxy defaults from System properties http.proxyHost and http.proxyPort or else you can override them using setProxy method.

Answer 4

Although this question is very old, but I see still there are no exact answer. I will try to answer the question here.

I believe the question in short here is how to set the proxy settings for the Apache commons HttpClient (org.apache.commons.httpclient.HttpClient).

Code snippet below should work :

HttpClient client = new HttpClient();
HostConfiguration hostConfiguration = client.getHostConfiguration();
hostConfiguration.setProxy("localhost", 8080);
client.setHostConfiguration(hostConfiguration);