org.apache.hadoop.gateway.dispatch.AbstractGatewayDispatch.java Source code

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Here is the source code for org.apache.hadoop.gateway.dispatch.AbstractGatewayDispatch.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.hadoop.gateway.dispatch;

import org.apache.hadoop.gateway.filter.GatewayResponse;
import org.apache.hadoop.io.IOUtils;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpUriRequest;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;

public abstract class AbstractGatewayDispatch implements Dispatch {

    private static final int STREAM_COPY_BUFFER_SIZE = 4096;
    private static final Set<String> REQUEST_EXCLUDE_HEADERS = new HashSet<>();

    static {
        REQUEST_EXCLUDE_HEADERS.add("Host");
        REQUEST_EXCLUDE_HEADERS.add("Authorization");
        REQUEST_EXCLUDE_HEADERS.add("Content-Length");
        REQUEST_EXCLUDE_HEADERS.add("Transfer-Encoding");
    }

    protected HttpClient client;

    @Override
    public void init() {
    }

    protected void writeResponse(HttpServletRequest request, HttpServletResponse response, InputStream stream)
            throws IOException {
        //    ResponseStreamer streamer =
        //        (ResponseStreamer)request.getAttribute( RESPONSE_STREAMER_ATTRIBUTE_NAME );
        //    if( streamer != null ) {
        //      streamer.streamResponse( stream, response.getOutputStream() );
        //    } else {
        if (response instanceof GatewayResponse) {
            ((GatewayResponse) response).streamResponse(stream);
        } else {
            OutputStream output = response.getOutputStream();
            IOUtils.copyBytes(stream, output, STREAM_COPY_BUFFER_SIZE);
            //KNOX-685: output.flush();
            output.close();
        }
        //    }
    }

    @Override
    public HttpClient getHttpClient() {
        return client;
    }

    @Override
    public void setHttpClient(HttpClient client) {
        this.client = client;
    }

    @Override
    public URI getDispatchUrl(HttpServletRequest request) {
        StringBuffer str = request.getRequestURL();
        String query = request.getQueryString();
        if (query != null) {
            str.append('?');
            str.append(query);
        }
        URI url = URI.create(str.toString());
        return url;
    }

    public void doGet(URI url, HttpServletRequest request, HttpServletResponse response)
            throws IOException, URISyntaxException {
        response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
    }

    public void doPost(URI url, HttpServletRequest request, HttpServletResponse response)
            throws IOException, URISyntaxException {
        response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
    }

    public void doPut(URI url, HttpServletRequest request, HttpServletResponse response)
            throws IOException, URISyntaxException {
        response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
    }

    public void doDelete(URI url, HttpServletRequest request, HttpServletResponse response)
            throws IOException, URISyntaxException {
        response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
    }

    public void doOptions(URI url, HttpServletRequest request, HttpServletResponse response)
            throws IOException, URISyntaxException {
        response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
    }

    public void copyRequestHeaderFields(HttpUriRequest outboundRequest, HttpServletRequest inboundRequest) {
        Enumeration<String> headerNames = inboundRequest.getHeaderNames();
        while (headerNames.hasMoreElements()) {
            String name = headerNames.nextElement();
            if (!outboundRequest.containsHeader(name) && !getOutboundRequestExcludeHeaders().contains(name)) {
                String value = inboundRequest.getHeader(name);
                outboundRequest.addHeader(name, value);
            }
        }
    }

    public Set<String> getOutboundRequestExcludeHeaders() {
        return REQUEST_EXCLUDE_HEADERS;
    }

}