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Java example source code file (HttpProxyServer.java)

This example Java source code file (HttpProxyServer.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytebuf, exception, fullhttprequest, fullhttpresponse, httpintermediaryhandler, httpobjectaggregator, httpproxyserver, httpservercodec, httpterminalhandler, inetsocketaddress, linebasedframedecoder, net, network, override, string, testmode

The HttpProxyServer.java Java example source code

/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package io.netty.handler.proxy;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.base64.Base64;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpHeaderNames;
import io.netty.handler.codec.http.HttpMethod;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpRequestDecoder;
import io.netty.handler.codec.http.HttpResponseEncoder;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http.HttpVersion;
import io.netty.util.CharsetUtil;
import io.netty.util.internal.StringUtil;

import java.net.InetSocketAddress;
import java.net.SocketAddress;

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.Matchers.*;
import static org.junit.Assert.*;

final class HttpProxyServer extends ProxyServer {

    HttpProxyServer(boolean useSsl, TestMode testMode, InetSocketAddress destination) {
        super(useSsl, testMode, destination);
    }

    HttpProxyServer(
            boolean useSsl, TestMode testMode, InetSocketAddress destination, String username, String password) {
        super(useSsl, testMode, destination, username, password);
    }

    @Override
    protected void configure(SocketChannel ch) throws Exception {
        ChannelPipeline p = ch.pipeline();
        switch (testMode) {
        case INTERMEDIARY:
            p.addLast(new HttpServerCodec());
            p.addLast(new HttpObjectAggregator(1));
            p.addLast(new HttpIntermediaryHandler());
            break;
        case TERMINAL:
            p.addLast(new HttpServerCodec());
            p.addLast(new HttpObjectAggregator(1));
            p.addLast(new HttpTerminalHandler());
            break;
        case UNRESPONSIVE:
            p.addLast(UnresponsiveHandler.INSTANCE);
            break;
        }
    }

    private boolean authenticate(ChannelHandlerContext ctx, FullHttpRequest req) {
        assertThat(req.method(), is(HttpMethod.CONNECT));

        if (testMode != TestMode.INTERMEDIARY) {
            ctx.pipeline().addBefore(ctx.name(), "lineDecoder", new LineBasedFrameDecoder(64, false, true));
        }

        ctx.pipeline().remove(HttpObjectAggregator.class);
        ctx.pipeline().get(HttpServerCodec.class).removeInboundHandler();

        boolean authzSuccess = false;
        if (username != null) {
            CharSequence authz = req.headers().get(HttpHeaderNames.PROXY_AUTHORIZATION);
            if (authz != null) {
                String[] authzParts = StringUtil.split(authz.toString(), ' ', 2);
                ByteBuf authzBuf64 = Unpooled.copiedBuffer(authzParts[1], CharsetUtil.US_ASCII);
                ByteBuf authzBuf = Base64.decode(authzBuf64);

                String expectedAuthz = username + ':' + password;
                authzSuccess = "Basic".equals(authzParts[0]) &&
                               expectedAuthz.equals(authzBuf.toString(CharsetUtil.US_ASCII));

                authzBuf64.release();
                authzBuf.release();
            }
        } else {
            authzSuccess = true;
        }

        return authzSuccess;
    }

    private final class HttpIntermediaryHandler extends IntermediaryHandler {

        private SocketAddress intermediaryDestination;

        @Override
        protected boolean handleProxyProtocol(ChannelHandlerContext ctx, Object msg) throws Exception {
            FullHttpRequest req = (FullHttpRequest) msg;
            FullHttpResponse res;
            if (!authenticate(ctx, req)) {
                res = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.UNAUTHORIZED);
                res.headers().set(HttpHeaderNames.CONTENT_LENGTH, 0);
            } else {
                res = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
                String uri = req.uri();
                int lastColonPos = uri.lastIndexOf(':');
                assertThat(lastColonPos, is(greaterThan(0)));
                intermediaryDestination = new InetSocketAddress(
                        uri.substring(0, lastColonPos), Integer.parseInt(uri.substring(lastColonPos + 1)));
            }

            ctx.write(res);
            ctx.pipeline().get(HttpServerCodec.class).removeOutboundHandler();
            return true;
        }

        @Override
        protected SocketAddress intermediaryDestination() {
            return intermediaryDestination;
        }
    }

    private final class HttpTerminalHandler extends TerminalHandler {

        @Override
        protected boolean handleProxyProtocol(ChannelHandlerContext ctx, Object msg) throws Exception {
            FullHttpRequest req = (FullHttpRequest) msg;
            FullHttpResponse res;
            boolean sendGreeting = false;

            if (!authenticate(ctx, req)) {
                res = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.UNAUTHORIZED);
                res.headers().set(HttpHeaderNames.CONTENT_LENGTH, 0);
            } else if (!req.uri().equals(destination.getHostString() + ':' + destination.getPort())) {
                res = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.FORBIDDEN);
                res.headers().set(HttpHeaderNames.CONTENT_LENGTH, 0);
            } else {
                res = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
                sendGreeting = true;
            }

            ctx.write(res);
            ctx.pipeline().get(HttpServerCodec.class).removeOutboundHandler();

            if (sendGreeting) {
                ctx.write(Unpooled.copiedBuffer("0\n", CharsetUtil.US_ASCII));
            }

            return true;
        }
    }
}

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