//
// ========================================================================
// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package com.facebook.presto.jdbc.internal.jetty.client.util;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.nio.charset.UnsupportedCharsetException;
import java.util.Locale;
import com.facebook.presto.jdbc.internal.jetty.client.api.Response;
import com.facebook.presto.jdbc.internal.jetty.client.api.Response.Listener;
import com.facebook.presto.jdbc.internal.jetty.client.api.Result;
import com.facebook.presto.jdbc.internal.jetty.http.HttpFields;
import com.facebook.presto.jdbc.internal.jetty.http.HttpHeader;
/**
* <p>Implementation of {@link Listener} that buffers the content up to a maximum length
* specified to the constructors.</p>
* <p>The content may be retrieved from {@link #onSuccess(Response)} or {@link #onComplete(Result)}
* via {@link #getContent()} or {@link #getContentAsString()}.</p>
*/
public abstract class BufferingResponseListener extends Listener.Adapter
{
private final int maxLength;
private volatile byte[] buffer = new byte[0];
private volatile String encoding;
/**
* Creates an instance with a default maximum length of 2 MiB.
*/
public BufferingResponseListener()
{
this(2 * 1024 * 1024);
}
/**
* Creates an instance with the given maximum length
*
* @param maxLength the maximum length of the content
*/
public BufferingResponseListener(int maxLength)
{
this.maxLength = maxLength;
}
@Override
public void onHeaders(Response response)
{
HttpFields headers = response.getHeaders();
long length = headers.getLongField(HttpHeader.CONTENT_LENGTH.asString());
if (length > maxLength)
{
response.abort(new IllegalArgumentException("Buffering capacity exceeded"));
}
else
{
String contentType = headers.get(HttpHeader.CONTENT_TYPE);
if (contentType != null)
{
String charset = "charset=";
int index = contentType.toLowerCase(Locale.ENGLISH).indexOf(charset);
if (index > 0)
{
String encoding = contentType.substring(index + charset.length());
// Sometimes charsets arrive with an ending semicolon
index = encoding.indexOf(';');
if (index > 0)
encoding = encoding.substring(0, index);
this.encoding = encoding;
}
}
}
}
@Override
public void onContent(Response response, ByteBuffer content)
{
long newLength = buffer.length + content.remaining();
if (newLength > maxLength)
{
response.abort(new IllegalArgumentException("Buffering capacity exceeded"));
}
else
{
byte[] newBuffer = new byte[(int)newLength];
System.arraycopy(buffer, 0, newBuffer, 0, buffer.length);
content.get(newBuffer, buffer.length, content.remaining());
buffer = newBuffer;
}
}
@Override
public abstract void onComplete(Result result);
public String getEncoding()
{
return encoding;
}
/**
* @return the content as bytes
* @see #getContentAsString()
*/
public byte[] getContent()
{
return buffer;
}
/**
* @return the content as a string, using the "Content-Type" header to detect the encoding
* or defaulting to UTF-8 if the encoding could not be detected.
* @see #getContentAsString(String)
*/
public String getContentAsString()
{
String encoding = this.encoding;
if (encoding == null)
return getContentAsString(StandardCharsets.UTF_8);
return getContentAsString(encoding);
}
/**
* @param encoding the encoding of the content bytes
* @return the content as a string, with the specified encoding
* @see #getContentAsString()
*/
public String getContentAsString(String encoding)
{
try
{
return new String(getContent(), encoding);
}
catch (UnsupportedEncodingException x)
{
throw new UnsupportedCharsetException(encoding);
}
}
/**
* @param encoding the encoding of the content bytes
* @return the content as a string, with the specified encoding
* @see #getContentAsString()
*/
public String getContentAsString(Charset encoding)
{
return new String(getContent(), encoding);
}
}