Question

Must comment on the code at every "/* Comment Here */" section about what the code is doing.

import java.io.*;

import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;

import java.util.Map;
import java.util.HashMap;

public class Configuration extends DefaultHandler
{
private Map map;
private String configurationFile;

/* Comment Here */
public Configuration(String configurationFile) throws ConfigurationException {
   this.configurationFile = configurationFile;

   map = new HashMap();

   try {
   // Use the default (non-validating) parser
   SAXParserFactory factory = SAXParserFactory.newInstance();

   // Parse the input
   SAXParser saxParser = factory.newSAXParser();
   saxParser.parse( new File(configurationFile), this);
   }
   catch (javax.xml.parsers.ParserConfigurationException pce) {
       throw new ConfigurationException("javax.xml.parsers.ParserConfigurationException");
   }
   catch (org.xml.sax.SAXException se) {
       throw new ConfigurationException("org.xml.sax.SAXException");
   }
   catch (java.io.IOException ioe) {
       throw new ConfigurationException("java.io.IOException");
   }
}

   /* Comment Here */
public void startElement(String namespaceURI,
String lName,   
String qName,   
Attributes attrs)  
throws SAXException
{
String elementName = lName; // element name
if ("".equals(elementName))
       elementName = qName; // namespaceAware = false

   /* Comment Here */
if (attrs != null) {
for (int i = 0; i < attrs.getLength(); i++) {
String aName = attrs.getLocalName(i); // Attr name
if ("".equals(aName))
           aName = attrs.getQName(i);

       /* Comment Here */
       map.put(elementName+"."+aName,attrs.getValue(i));
}
}
}

   /* Comment Here */
   public String getLogFile() {
       return (String)map.get("logfile.log");
   }

   /* Comment Here */
   public String getDocBase() {
       return (String)map.get("context.docBase");
   }

   /* Comment Here */
   public String getServerName() {
       return (String)map.get("webserver.title");
   }
}

Answer 1

import java.io.*;

import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;

import java.util.Map;
import java.util.HashMap;

public class Configuration extends DefaultHandler
{
private Map map;
private String configurationFile;

/* Constructor is created which takes input string from parameter and stores into this class private data type string which is configurationFile as it's a private variable of the class it cannot be accessed by any other class except Configuration classs itself. If any Exception occurs the it is handled by ConfigurationException itself */

/* Map instance is also created & as we can see XML is also parsed in this section of class and its expections are properlly handled */
public Configuration(String configurationFile) throws ConfigurationException {
   this.configurationFile = configurationFile;

   map = new HashMap();

   try {
   // Use the default (non-validating) parser
   SAXParserFactory factory = SAXParserFactory.newInstance();

   // Parse the input
   SAXParser saxParser = factory.newSAXParser();
   saxParser.parse( new File(configurationFile), this);
   }
   catch (javax.xml.parsers.ParserConfigurationException pce) {
       throw new ConfigurationException("javax.xml.parsers.ParserConfigurationException");
   }
   catch (org.xml.sax.SAXException se) {
       throw new ConfigurationException("org.xml.sax.SAXException");
   }
   catch (java.io.IOException ioe) {
       throw new ConfigurationException("java.io.IOException");
   }
}

   /* This funtion takes parameters and stores it to its local variable and exceptions are properly handled by its exceptionm handlers */
public void startElement(String namespaceURI,
String lName,   
String qName,   
Attributes attrs)  
throws SAXException
{
String elementName = lName; // element name
if ("".equals(elementName))
       elementName = qName; // namespaceAware = false

   /* We check for attris if its not null then the condition is fulfilled and it enter the if condition */
if (attrs != null) {
for (int i = 0; i < attrs.getLength(); i++) {
String aName = attrs.getLocalName(i); // Attr name
if ("".equals(aName))
           aName = attrs.getQName(i);

       /* aName and its respective values are inserted into the map which has been defiened into the constructor. */
       map.put(elementName+"."+aName,attrs.getValue(i));
}
}
}

   /* Returns the local name from Log File */
   public String getLogFile() {
       return (String)map.get("logfile.log");
   }

   /* The docBase attribute is a path to the WAR file or exploded deployment directory. It is relative to the webapps directory,. it return the value from map */
   public String getDocBase() {
       return (String)map.get("context.docBase");
   }

   /* Returns the server name which is in the map */
   public String getServerName() {
       return (String)map.get("webserver.title");
   }
}