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.html;
016    
017    import java.util.Collections;
018    import java.util.Iterator;
019    import java.util.List;
020    import java.util.Properties;
021    import java.util.StringTokenizer;
022    
023    import org.apache.tapestry.BaseComponent;
024    import org.apache.tapestry.IMarkupWriter;
025    import org.apache.tapestry.IRender;
026    import org.apache.tapestry.IRequestCycle;
027    import org.apache.tapestry.web.WebUtils;
028    
029    /**
030     * Supports the {@link org.apache.tapestry.pages.Exception} page by displaying the request,
031     * session, servlet context and servlet object for the current request.
032     * 
033     * @author Howard M. Lewis Ship
034     * @since 4.0
035     */
036    public abstract class RequestDisplay extends BaseComponent
037    {
038        private boolean _even;
039    
040        public void renderSystemProperties(IMarkupWriter writer)
041        {
042            _even = true;
043    
044            Properties p = System.getProperties();
045    
046            String pathSeparator = p.getProperty("path.separator");
047    
048            writer.begin("div");
049            writer.attribute("class", "described-object-title");
050            writer.print("JVM System Properties");
051            writer.end();
052            writer.println();
053    
054            writer.begin("table");
055            writer.attribute("class", "described-object");
056    
057            Iterator i = WebUtils.toSortedList(p.keys()).iterator();
058    
059            while (i.hasNext())
060            {
061                String key = (String) i.next();
062                String value = p.getProperty(key);
063    
064                renderKeyAndValue(writer, key, value, pathSeparator);
065            }
066    
067            writer.end();
068        }
069    
070        private void renderKeyAndValue(IMarkupWriter writer, String key, String value,
071                String pathSeparator)
072        {
073            String[] values = split(key, value, pathSeparator);
074    
075            for (int i = 0; i < values.length; i++)
076            {
077                writer.begin("tr");
078    
079                writer.attribute("class", _even ? "even" : "odd");
080    
081                _even = !_even;
082    
083                writer.begin("th");
084    
085                if (i == 0)
086                    writer.print(key);
087    
088                writer.end();
089                writer.begin("td");
090                writer.print(values[i]);
091                writer.end("tr");
092                writer.println();
093            }
094        }
095    
096        private String[] split(String key, String value, String pathSeparator)
097        {
098            if (!key.endsWith(".path"))
099                return new String[]
100                { value };
101    
102            StringTokenizer tokenizer = new StringTokenizer(value, pathSeparator);
103            List values = Collections.list(tokenizer);
104    
105            return (String[]) values.toArray(new String[values.size()]);
106        }
107    
108        public IRender getSystemPropertiesRenderer()
109        {
110            return new IRender()
111            {
112                public void render(IMarkupWriter writer, IRequestCycle cycle)
113                {
114                    renderSystemProperties(writer);
115                }
116            };
117        }
118    }