Apache HttpComponents:org.apache.http.client.ClientProtocolException

Question

所以我使用apache HttpComponents来处理java中的http请求.现在我想重用一下DefaultHttpClient,应该对这个例子有什么看法:http://wiki.apache.org/HttpComponents/QuickStart .示例本身给出了一个ssl错误,因此我进行了修改并简化了一点.现在我总是得到一个org.apache.http.client.ClientProtocolException

这是我的示例程序,基本上我只是使用相同的请求2个网页DefaultHttpClient.

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;


public class ClientFormLogin {

    public static void main(String[] args) throws Exception {

        DefaultHttpClient httpclient = new DefaultHttpClient();

        //Handle first request.
        HttpGet httpget = new HttpGet("http://tweakers.net/nieuws/82969/amazon-nederland-opent-digitale-deuren-in-september.html");
        HttpResponse response = httpclient.execute(httpget);
        System.out.println("Execute finished");
        HttpEntity entity = response.getEntity();
        String page = readInput(entity.getContent());
        System.out.println("Request one finished without problems!");

        //Handle second request
        HttpGet httpost = new HttpGet("http://gathering.tweakers.net/forum/list_messages/1506977/last");
        response = httpclient.execute(httpost);
        entity = response.getEntity();
        page = readInput(entity.getContent());
        System.out.println("Request two finished without problems!");
    }

    private static String readInput(InputStream in) throws IOException {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        byte bytes[] = new byte[1024];

        int n = in.read(bytes);

        while (n != -1) {
            out.write(bytes, 0, n);
            n = in.read(bytes);
        }

        return new String(out.toString());
    }
}

当runnig我的例子我得到了下面的错误

Request one finished without problems!
Exception in thread "main" org.apache.http.client.ClientProtocolException
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:909)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:784)
    at ClientFormLogin.main(ClientFormLogin.java:29)
Caused by: org.apache.http.HttpException: Unable to establish route: planned = {}->http://gathering.tweakers.net; current = {}->http://tweakers.net
    at org.apache.http.impl.client.DefaultRequestDirector.establishRoute(DefaultRequestDirector.java:842)
    at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:645)
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:480)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906)
    ... 3 more

任何人都可以给我一些指示我如何解决这个问题,除了DefaultHttpClient为每个请求使用new .

---

编辑

我刚刚发现,如果我留在同一个域,我没有问题,所以:

page1: 'http://tweakers.net/nieuws/82969/amazon-nederland-opent-digitale-deuren-in-september.html'
page2: 'http://tweakers.net/nieuws/82973/website-nujij-belandt-op-zwarte-lijst-google-door-malware.html'

如果我到达,我没有问题:

page1: 'http://tweakers.net/nieuws/82969/amazon-nederland-opent-digitale-deuren-in-september.html'
page2: 'http://gathering.tweakers.net/forum/list_messages/1506076/last'

我收到了错误.

我在发布问题后一分钟就看到了这一点.除非有人能告诉我如何才能使用相同的2个域名,DefaultHttpClient我的问题已经回答了.

Answer 1

这可能是由于v4.2 BasicClientConnectionManager中最近的一个错误影响了跨站点重定向.见http://issues.apache.org/jira/browse/HTTPCLIENT-1193.

根据维护者的说法,一个临时解决方法是使用SingleClientConnManager或PoolingClientConnectionManager.也许是这样的:

ClientConnectionManager connManager = new PoolingClientConnectionManager();
DefaultHttpClient httpclient = new DefaultHttpClient(connManager);
...