TinyProxyDemo.java

package com.example.tinyproxy;

import org.apache.http.HttpHost;
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.conn.HttpHostConnectException;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class TinyProxyDemo {

    public static void main(String[] args) throws Exception {
        try (CloseableHttpClient client = HttpClients.createDefault()) {
            HttpHost target = new HttpHost("jsonplaceholder.typicode.com", 443, "https");
            HttpHost proxy = new HttpHost("127.0.0.1", 8888, "http");

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

            HttpGet request = new HttpGet("/posts/42");
            request.setConfig(config);

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

            try (CloseableHttpResponse response = client.execute(target, request)) {
                System.out.println("----------------------------------------");
                System.out.println(response.getStatusLine());
                System.out.println(EntityUtils.toString(response.getEntity()));
            } catch (HttpHostConnectException e) {
                if (e.getHost().equals(proxy)) {

                    System.out.println("Proxy " + proxy + " is unavailable, making request direct to " + target);

                    request.setConfig(null);

                    try (CloseableHttpResponse response = client.execute(target, request)) {
                        System.out.println("----------------------------------------");
                        System.out.println(response.getStatusLine());
                        System.out.println(EntityUtils.toString(response.getEntity()));
                    }

                } else {
                    throw e;
                }
            }
        }
    }

}