001    // Copyright 2005 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    
015    package org.apache.tapestry.contrib.components;
016    
017    import java.io.BufferedOutputStream;
018    import java.io.CharArrayWriter;
019    import java.io.ObjectOutputStream;
020    
021    import org.apache.tapestry.AbstractComponent;
022    import org.apache.tapestry.IMarkupWriter;
023    import org.apache.tapestry.IRequestCycle;
024    import org.apache.tapestry.util.io.BinaryDumpOutputStream;
025    
026    /**
027     * Used to dump out an object's serialized representation in a mix of hex and ascii. The output is
028     * formatted for a fixed width font, typically should be enclosed in <pre> tags.
029     * 
030     * @see org.apache.tapestry.util.io.BinaryDumpOutputStream
031     * @author Howard M. Lewis Ship
032     * @since 4.0
033     */
034    
035    public abstract class DumpObject extends AbstractComponent
036    {
037        // Parameters:
038    
039        public abstract Object getObject();
040    
041        protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
042        {
043            if (cycle.isRewinding())
044                return;
045    
046            String asText = convert(getObject());
047    
048            writer.print(asText);
049        }
050    
051        String convert(Object object)
052        {
053            try
054            {
055                CharArrayWriter writer = new CharArrayWriter();
056                BinaryDumpOutputStream bdos = new BinaryDumpOutputStream(writer);
057                ObjectOutputStream oos = new ObjectOutputStream(new BufferedOutputStream(bdos));
058    
059                oos.writeObject(object);
060    
061                oos.close();
062    
063                return writer.toString();
064            }
065            catch (Exception ex)
066            {
067                return ex.toString();
068            }
069        }
070    }