import java.io.IOException;
import java.net.URI;

import org.apache.http.Header;
import org.apache.http.HeaderIterator;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.ProtocolVersion;
import org.apache.http.RequestLine;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.message.BasicHttpRequest;
import org.apache.http.params.HttpParams;
import org.apache.http.protocol.HttpContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ApacheHttpClientExecuteSSRF extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        try {

            String sink = request.getParameter("host"); // $ Source

            HttpHost host = new HttpHost(sink);
            HttpRequest req = new BasicHttpRequest("GET", "/");
            HttpUriRequest uriReq = new HttpUriRequest() {
                @Override
                public String getMethod() {
                    return "GET";
                }

                @Override
                public URI getURI() {
                    return URI.create("https://" + sink);
                }

                @Override
                public void abort() throws UnsupportedOperationException {
                }

                @Override
                public boolean isAborted() {
                    return false;
                }

                @Override
                public RequestLine getRequestLine() {
                    return null;
                }

                @Override
                public ProtocolVersion getProtocolVersion() {
                    return null;
                }

                @Override
                public boolean containsHeader(String name) {
                    return false;
                }

                @Override
                public Header[] getHeaders(String name) {
                    return null;
                }

                @Override
                public Header getFirstHeader(String name) {
                    return null;
                }

                @Override
                public Header getLastHeader(String name) {
                    return null;
                }

                @Override
                public Header[] getAllHeaders() {
                    return null;
                }

                @Override
                public void addHeader(Header header) {
                }

                @Override
                public void addHeader(String name, String value) {
                }

                @Override
                public void setHeader(Header header) {
                }

                @Override
                public void setHeader(String name, String value) {
                }

                @Override
                public void setHeaders(Header[] headers) {
                }

                @Override
                public void removeHeader(Header header) {
                }

                @Override
                public void removeHeaders(String name) {
                }

                @Override
                public HeaderIterator headerIterator() {
                    return null;
                }

                @Override
                public HeaderIterator headerIterator(String name) {
                    return null;
                }

                @Override
                public HttpParams getParams() {
                    return null;
                }

                @Override
                public void setParams(HttpParams params) {
                }
            };
            HttpContext context = null;
            HttpClient client = new HttpClient() {
                @Override
                public HttpResponse execute(HttpHost target, HttpRequest request) throws IOException {
                    return null;
                }

                @Override
                public HttpResponse execute(HttpHost target, HttpRequest request, HttpContext context) throws IOException {
                    return null;
                }

                @Override
                public <T> T execute(HttpHost target, HttpRequest request, ResponseHandler<? extends T> responseHandler)
                        throws IOException {
                    return null;
                }

                @Override
                public <T> T execute(HttpHost target, HttpRequest request, ResponseHandler<? extends T> responseHandler,
                        HttpContext context) throws IOException {
                    return null;
                }

                @Override
                public HttpResponse execute(HttpUriRequest request) throws IOException {
                    return null;
                }

                @Override
                public HttpResponse execute(HttpUriRequest request, HttpContext context) throws IOException {
                    return null;
                }

                @Override
                public <T> T execute(HttpUriRequest request, ResponseHandler<? extends T> responseHandler)
                        throws IOException {
                    return null;
                }

                @Override
                public <T> T execute(HttpUriRequest request, ResponseHandler<? extends T> responseHandler,
                        HttpContext context) throws IOException {
                    return null;
                }
            };
            ResponseHandler<Object> handler = null;

            client.execute(host, req); // $ Alert
            client.execute(host, req, context); // $ Alert
            client.execute(host, req, handler); // $ Alert
            client.execute(host, req, handler, context); // $ Alert
            client.execute(uriReq); // $ Alert
            client.execute(uriReq, context); // $ Alert
            client.execute(uriReq, handler); // $ Alert
            client.execute(uriReq, handler, context); // $ Alert

        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}