com.continuuity.http.InternalHttpResponder.java Source code

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Here is the source code for com.continuuity.http.InternalHttpResponder.java

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/**
 * Copyright 2012-2014 Continuuity, Inc.
 *
 * Licensed 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 com.continuuity.http;

import com.google.common.base.Charsets;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import com.google.common.collect.Multimap;
import com.google.common.io.ByteStreams;
import com.google.common.io.Files;
import com.google.common.io.InputSupplier;
import com.google.gson.Gson;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBufferInputStream;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.handler.codec.http.HttpResponseStatus;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;
import java.nio.ByteBuffer;
import java.util.List;

/**
 * InternalHttpResponder is used when a handler is being called internally by some other handler, and thus there
 * is no need to go through the network.  It stores the status code and content in memory and returns them when asked.
 */
public class InternalHttpResponder implements HttpResponder {
    private int statusCode;
    private List<ChannelBuffer> contentChunks;
    private InputSupplier<? extends InputStream> inputSupplier;

    private static final Gson gson = new Gson();

    public InternalHttpResponder() {
        contentChunks = Lists.newLinkedList();
        statusCode = 0;
    }

    @Override
    public void sendJson(HttpResponseStatus status, Object object) {
        sendJson(status, object, object.getClass());
    }

    @Override
    public void sendJson(HttpResponseStatus status, Object object, Type type) {
        sendJson(status, object, type, gson);
    }

    @Override
    public void sendJson(HttpResponseStatus status, Object object, Type type, Gson gson) {
        setResponseContent(status, gson.toJson(object, type).getBytes(Charsets.UTF_8));
    }

    @Override
    public void sendString(HttpResponseStatus status, String data) {
        if (data == null) {
            sendStatus(status);
        } else {
            setResponseContent(status, data.getBytes(Charsets.UTF_8));
        }
    }

    @Override
    public void sendStatus(HttpResponseStatus status) {
        statusCode = status.getCode();
    }

    @Override
    public void sendStatus(HttpResponseStatus status, Multimap<String, String> headers) {
        statusCode = status.getCode();
    }

    @Override
    public void sendByteArray(HttpResponseStatus status, byte[] bytes, Multimap<String, String> headers) {
        setResponseContent(status, bytes);
    }

    @Override
    public void sendBytes(HttpResponseStatus status, ByteBuffer buffer, Multimap<String, String> headers) {
        byte[] bytes = new byte[buffer.remaining()];
        int position = buffer.position();
        buffer.get(bytes);
        buffer.position(position);
        setResponseContent(status, bytes);
    }

    @Override
    public void sendError(HttpResponseStatus status, String errorMessage) {
        Preconditions.checkArgument(!status.equals(HttpResponseStatus.OK),
                "Response status cannot be OK for errors");

        setResponseContent(status, errorMessage.getBytes(Charsets.UTF_8));
    }

    @Override
    public void sendChunkStart(HttpResponseStatus status, Multimap<String, String> headers) {
        statusCode = status.getCode();
        contentChunks.clear();
    }

    @Override
    public void sendChunk(ChannelBuffer content) {
        contentChunks.add(content);
    }

    @Override
    public void sendChunkEnd() {
        ChannelBuffer[] chunks = new ChannelBuffer[contentChunks.size()];
        contentChunks.toArray(chunks);
        final ChannelBuffer body = ChannelBuffers.wrappedBuffer(chunks);
        body.markReaderIndex();

        inputSupplier = new InputSupplier<InputStream>() {
            @Override
            public InputStream getInput() throws IOException {
                body.resetReaderIndex();
                return new ChannelBufferInputStream(body);
            }
        };
    }

    @Override
    public void sendContent(HttpResponseStatus status, ChannelBuffer content, String contentType,
            Multimap<String, String> headers) {
        setResponseContent(status, content.array());
    }

    private void setResponseContent(HttpResponseStatus status, byte[] content) {
        statusCode = status.getCode();
        inputSupplier = ByteStreams.newInputStreamSupplier(content);
    }

    @Override
    public void sendFile(File file, Multimap<String, String> headers) {
        statusCode = HttpResponseStatus.OK.getCode();
        inputSupplier = Files.newInputStreamSupplier(file);
    }

    public InternalHttpResponse getResponse() {
        return new BasicInternalHttpResponse(statusCode, inputSupplier);
    }
}