001// Copyright 2009, 2012 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.internal.services;
016
017import org.apache.tapestry5.internal.util.Base64OutputStream;
018import org.apache.tapestry5.internal.util.MacOutputStream;
019import org.apache.tapestry5.internal.util.TeeOutputStream;
020import org.apache.tapestry5.services.ClientDataSink;
021import org.apache.tapestry5.services.URLEncoder;
022
023import java.io.BufferedOutputStream;
024import java.io.IOException;
025import java.io.ObjectOutputStream;
026import java.io.OutputStream;
027import java.security.Key;
028import java.util.zip.GZIPOutputStream;
029
030public class ClientDataSinkImpl implements ClientDataSink
031{
032    private final Base64OutputStream base64OutputStream;
033
034    private final ObjectOutputStream objectOutputStream;
035
036    private final URLEncoder urlEncoder;
037
038    private boolean closed;
039
040    private final MacOutputStream macOutputStream;
041
042    public ClientDataSinkImpl(URLEncoder urlEncoder, Key hmacKey) throws IOException
043    {
044        this.urlEncoder = urlEncoder;
045
046        base64OutputStream = new Base64OutputStream();
047        macOutputStream =  MacOutputStream.streamFor(hmacKey);
048
049        final BufferedOutputStream pipeline = new BufferedOutputStream(new GZIPOutputStream(
050                new TeeOutputStream(macOutputStream, base64OutputStream)));
051
052        OutputStream guard = new OutputStream()
053        {
054            @Override
055            public void write(int b) throws IOException
056            {
057                pipeline.write(b);
058            }
059
060            @Override
061            public void close() throws IOException
062            {
063                closed = true;
064
065                pipeline.close();
066            }
067
068            @Override
069            public void flush() throws IOException
070            {
071                pipeline.flush();
072            }
073
074            @Override
075            public void write(byte[] b) throws IOException
076            {
077                pipeline.write(b);
078            }
079
080            @Override
081            public void write(byte[] b, int off, int len) throws IOException
082            {
083                pipeline.write(b, off, len);
084            }
085        };
086
087
088        objectOutputStream = new ObjectOutputStream(guard);
089    }
090
091    public ObjectOutputStream getObjectOutputStream()
092    {
093        return objectOutputStream;
094    }
095
096    public String getClientData()
097    {
098        if (!closed)
099        {
100            try
101            {
102                objectOutputStream.close();
103            } catch (IOException ex)
104            {
105                // Ignore.
106            }
107        }
108
109        return macOutputStream.getResult() + ":" + base64OutputStream.toBase64();
110    }
111
112    public String getEncodedClientData()
113    {
114        return urlEncoder.encode(getClientData());
115    }
116}