Java使用okhttp3调用Http代理IP的代码样例

温馨提示：
1. 此样例同时支持访问http和https网页
2. 使用用户名密码访问的情况下，每次请求httpclient不会发送两次进行认证从而导致请求耗时增加，建议使用白名单访问
3. 使用用户名密码验证时必须重写 Authenticator 的 authenticate方法

import okhttp3.*;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Proxy;

public class TestProxyOKHttpClient {
	public static void main(String args[]) throws IOException {
		// 目标网站
		String targetUrl = "https://example.com";

		// 用户名密码授权
		final String username = "username";
		final String password = "password";

		String ip = "159.138.141.125";   // 代理服务器IP
		int port = 16875;

		Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(ip, port));
		Authenticator authenticator = new Authenticator() {
			@Override
			public Request authenticate(Route route, Response response) throws IOException {
				String credential = Credentials.basic(username, password);
				return response.request().newBuilder()
						.header("Proxy-Authorization", credential)
						.build();
			}
		};
		OkHttpClient client = new OkHttpClient.Builder()
				.proxy(proxy)
				.proxyAuthenticator(authenticator)
				.build();

		Request request = new Request.Builder()
				.url(targetUrl)
				.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36
				 (KHTML, like Gecko) Chrome/60.0.3100.0 Safari/537.36")
				.build();

		Response response = client.newCall(request).execute();
		System.out.println(response.body().string());

	}
}