HttpClient4.5.6设置代理以及代理验证（用户名和密码）

HttpClient4.5.6设置代理以及代理验证（用户名和密码）

下载 httpcomponents-client-4.5.6-bin 在Apache官网有，贴上链接：http://hc.apache.org/downloads.cgi 下载以后把对应的包导入工程即可（java和maven工程都行），下面说明如何设置代理验证:

import java.io.IOException;
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.junit.jupiter.api.Test;

public class DownloadPage
{
    @Test
    public void downLoad()
    {
        try
        {
            // 设置代理HttpHost
            HttpHost proxy = new HttpHost("openproxy.huawei.com", 8080, "http");

            // 设置要访问的HttpHost,即是目标站点的HttpHost
            HttpHost target = new HttpHost("baidu.com", 80);

            // 设置认证
            CredentialsProvider provider = new BasicCredentialsProvider();

            provider.setCredentials(new AuthScope(proxy), new UsernamePasswordCredentials("username", "password"));

            CloseableHttpClient httpClient = HttpClients.custom().setDefaultCredentialsProvider(provider).build();

            RequestConfig config = RequestConfig.custom().setProxy(proxy).build();

            HttpGet httpGet = new HttpGet("/");

            httpGet.setConfig(config);

            CloseableHttpResponse resp = httpClient.execute(target, httpGet);

            if (resp.getStatusLine().getStatusCode() == 200)
            {
                System.out.println("OK");
            }
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
}

在执行请求时，请求设置用代理进行访问，但是代理需要验证，那么就会找到provider设置相关联的用户名和密码进行验证，所以设置provider时需要注意关联。说明一下setCredentials()这个方法可以添加多个验证账号和密码，看源代码可知就是ConcurrentHashMap（Map）的操作。