PropertiesReader

// 2012-11-30 johnpfeiffer
// TODO: ascertain whether when duplicates exist it always gets the last value from the source?
// TODO: case insensitive method?
// TODO: static factory constructor build() that allows for caseInsensitive option


package kittyandbear.net;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Properties;
import java.util.Set;

public class PropertiesReader
{
    public static final String CLASSVERSION = "0.30";
    static final String NEWLINE = System.getProperty("line.separator");
    private Properties properties;


    PropertiesReader( String pathFile ) throws IOException, IllegalArgumentException
    {
        if( pathFile == null )
        {
            throw new IllegalArgumentException( "ERROR: pathFile cannot be null" );
        }
        if( pathFile.isEmpty() )
        {
            throw new IllegalArgumentException( "ERROR: pathFile cannot be empty" );
        }
        try
        {
            // FileReader can support UTF8 better and BufferedReader should support larger files better
            BufferedReader input = new BufferedReader( new FileReader( pathFile ) );
            properties = new Properties();
            properties.load( input );
            input.close();

        }catch( FileNotFoundException e )
        {
            throw new IllegalArgumentException( "ERROR: file not found: " + e.getMessage() );
        }
    }

    protected Properties get()
    {
        return properties;
    }

    public String getPropertyValue( String key ) throws IllegalArgumentException
    {
        if( key == null )
        {
            throw new IllegalArgumentException( "ERROR: key cannot be null" );
        }
        if( key.isEmpty() )
        {
            throw new IllegalArgumentException( "ERROR: key cannot be empty" );
        }
        return properties.getProperty( key );
    }

    public ArrayList <String> getKeysAndValues()
    {
        ArrayList <String> unsortedList = new ArrayList <String>();
        Enumeration <?> props = properties.propertyNames();
        while( props.hasMoreElements() )
        {
            String key = (String) props.nextElement();
            String value = properties.getProperty( key );
            unsortedList.add( key + "=" + value );
        }
        return unsortedList;
    }

    public ArrayList <String> getKeysSorted()
    {
        ArrayList <String> sortedList = new ArrayList <String>();
        Set <Object> set = properties.keySet();
        Iterator <Object> it = set.iterator();
        while( it.hasNext() )
        {
            sortedList.add( it.next().toString() );
        }
        Collections.sort( sortedList );         // case sensitive so A before a
        return sortedList;
    }

    public ArrayList <String> getKeysAndValuesSortedByKeys()
    {
        ArrayList <String> sortedKeyAndValueList = new ArrayList <String>();
        ArrayList <String> sortedKeyList = getKeysSorted();     // case sensitive so A before a
        for( String key : sortedKeyList )
        {
            sortedKeyAndValueList.add( key + "=" + properties.getProperty( key ) );
        }
        return sortedKeyAndValueList;
    }

    public String getKeysAndValuesSortedByKeysString() // convenience method
    {
        StringBuilder strb = new StringBuilder();

        ArrayList <String> source = getKeysAndValuesSortedByKeys();     // case sensitive so A before a
        for( String line : source )
        {
            strb.append( line + NEWLINE );
        }
        return strb.toString();
    }

} // end class