All,
Here is the source that I came up with to do this. Please critique
it. I would like to have concrete comments as to how it could be
improved For example, I read a TechTip that said it would be better
to use a scanner or at least String.split() in lieu of the
StringTokenizer.
Todd
//=========================================
import java.util.StringTokenizer;
import java.util.Vector;
/**
*
* @author heidenthal
*/
public class DataRecord
{
public DataRecord( String value, String description )
{
// Fill the data record with the passed information
this.value = new String( value );
this.description = new String( description );
// The record value needs to have its data type defined
// for the typed return of the value
dataType = determineType( value );
}
public String getDescription()
{
return description;
}
public <T> T getValue()
{
@SuppressWarnings( "unchecked" ) // TODO check cast and don't
suppress
Class <T> type = dataType.getClassType();
return type.cast( dataType.castValue( value ) );
}
public Class getClassType()
{
return dataType.getClassType();
}
private DataType determineType( String value )
{
dataType = DataType.STRING;
// boolean type
if( isBoolean( value ) )
{
dataType = DataType.BOOLEAN;
}
else if( isInteger( value ) ) // int type
{
dataType = DataType.INTEGER;
}
else if( isDouble( value ) ) // double type
{
dataType = DataType.DOUBLE;
}
else if( isDoubleArray( value ) ) // double[] type
{
dataType = DataType.DOUBLE_ARRAY;
}
return dataType;
}
private boolean isBoolean( String value )
{
if( value.equalsIgnoreCase( "true" ) ||
value.equalsIgnoreCase( "false" ) )
{
return true;
}
return false;
}
private boolean isInteger( String value )
{
try
{
Integer.parseInt( value );
return true;
}
catch( Exception exception )
{
return false;
}
}
private boolean isDouble( String value )
{
try
{
Double.parseDouble( value );
return true;
}
catch( Exception exception )
{
return false;
}
}
private boolean isDoubleArray( String value )
{
if( value.contains( "{" ) && value.contains( "}" ) )
{
return true;
}
return false;
}
private String value;
private String description;
private DataType dataType;
@SuppressWarnings( "unchecked" ) // TODO check cast and don't
suppress
private enum DataType
{
STRING( String.class )
{
String castValue( String value )
{
return value;
}
},
BOOLEAN( Boolean.class )
{
Boolean castValue( String value )
{
return Boolean.parseBoolean( value );
}
},
INTEGER( Integer.class )
{
Integer castValue( String value )
{
return Integer.parseInt( value );
}
},
DOUBLE( Double.class )
{
Double castValue( String value )
{
return Double.parseDouble( value );
}
},
DOUBLE_ARRAY( Double[].class )
{
Double[] castValue( String value )
{
Vector<Double> values = new Vector<Double>();
StringTokenizer tokenizer =
new StringTokenizer( value.substring( 1 ),
" }" );
while( tokenizer.hasMoreTokens() )
{
values.add( Double.parseDouble( tokenizer.nextToken() ) );
}
Double[] valuesArray = new Double[values.size()];
valuesArray = values.toArray( valuesArray );
return valuesArray;
}
};
DataType( Class clazz )
{
this.clazz = clazz;
}
abstract <T> T castValue( String value );
Class getClassType()
{
return clazz;
}
private Class clazz;
}
}
//========================================
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Locale;
import java.util.StringTokenizer;
/**
*
* @author heidenthal
*/
public class DataCollection extends HashMap<String, DataRecord>
{
public DataCollection( String filename )
{
buildDefaultMap( filename );
}
public void buildDefaultMap( String filename )
{
String line = null;
InputStream reader =
Class.class.getResourceAsStream( filename );
try
{
BufferedReader bufferedReader =
new BufferedReader( new
InputStreamReader( reader ) );
while( (line = bufferedReader.readLine()) != null )
{
// Break the line into the key and data record
StringTokenizer str = new StringTokenizer( line,"=" );
// Get the key for the data
String key =
str.nextToken().trim().toUpperCase(Locale.ENGLISH);
// Get the record value
String value = str.nextToken( "=," ).trim();
// Get the description (if it exists)
String description = str.nextToken( "\n" ).trim();
// Create a new data record and add it to the
collection
DataRecord dataRecord = new DataRecord( value,
description );
this.put( key, dataRecord );
}
}
catch( IOException ioException )
{
System.err.println( "Unable to open " + filename );
System.err.println( ioException );
}
}
public <T> T get( String key ) throws NullPointerException
{
DataRecord dataRecord =
super.get( key.trim().toUpperCase(Locale.ENGLISH) );
@SuppressWarnings( "unchecked" ) // TODO check cast and don't
suppress
Class<T> type = dataRecord.getClassType();
return type.cast( dataRecord.getValue() );
}
}
