Utils.java

package de.mpicbg.knime.knutils;

import org.knime.core.data.DataCell;
import org.knime.core.data.DataType;
import org.knime.core.data.def.DoubleCell;
import org.knime.core.data.def.IntCell;
import org.knime.core.data.def.StringCell;


/**
 * Document me!
 *
 * @author Holger Brandl
 */
public class Utils {

    /**
     * Try to determine whether this application is running under Windows or some other platform by examing the
     * "os.name" property.
     *
     * @return true if this application is running under a Windows OS
     */
    public static boolean isWindowsPlatform() {
        String os = System.getProperty("os.name");
        return os != null && os.startsWith("Windows");
    }


    public static boolean isMacOSPlatform() {
        String os = System.getProperty("os.name");
        return os != null && os.equals("Mac OS X");
    }
    
    /**
     * converts a float array into a double array
     * @param input
     * @return array with doubles
     */
    public static double[] convertFloatsToDoubles(float[] input)
    {
        if (input == null)
        {
            return null;
        }
        double[] output = new double[input.length];
        for (int i = 0; i < input.length; i++)
        {
            output[i] = input[i];
        }
        return output;
    }
    
    /**
     * converts a double array into a float array; USE WITH CAUTION as precision might be lost! 
     * @param input
     * @return array with doubles
     */
    public static float[] convertDoublesToFloats(double[] input)
    {
        if (input == null)
        {
            return null;
        }
        float[] output = new float[input.length];
        for (int i = 0; i < input.length; i++)
        {
            output[i] = (float) input[i];
        }
        return output;
    }

    /**
     * retrieves the KNIME DataType corresponding to a java class
     *
     * @param intStrOrDouble
     * @return
     */
    public static DataType mapType(Class intStrOrDouble) {
        if (intStrOrDouble.equals(Integer.class)) {
            return IntCell.TYPE;

        } else if (intStrOrDouble.equals(Double.class) || intStrOrDouble.equals(Float.class)) {
            return DoubleCell.TYPE;

        } else if (intStrOrDouble.equals(String.class)) {
            return StringCell.TYPE;

        } else {
            throw new RuntimeException("Could not map unknown type '" + intStrOrDouble + "'to knime-type");
        }
    }
    
    /**
     * Creates a new data cell of the given data type with the value
     * supports, missing, double, integer, string (TODO: and date/time)
     * @param dtype
     * @param value
     * @return data cell, or null if given data type is not supported or value cannot be casted to given data type
     */
    public static DataCell createCellByType(DataType dtype, Object value) {
    	
    	// MISSING
    	if (value == null) {
            return DataType.getMissingCell();
        }

    	// DOUBLE
        if (dtype.equals(DoubleCell.TYPE)) {
            if (value instanceof String) {
                if (((String) value).trim().isEmpty()) {
                    return DataType.getMissingCell();
                }
                try {
                	value = Double.parseDouble((String) value);
                } catch(NumberFormatException e) {
                	return null;
                }
            }

            if (value instanceof Integer) {
                value = ((Integer) value).doubleValue();
            }

            return new DoubleCell((Double) value);
        }
        
        // INTEGER
        if (dtype.equals(IntCell.TYPE)) {
            if (value instanceof String) {
                if (((String) value).trim().isEmpty()) {
                    return DataType.getMissingCell();
                }

                try {
                	value = Integer.parseInt((String) value);
                } catch(NumberFormatException e) {
                	return null;
                }
            }

            return new IntCell((Integer) value);
        }
        
        //STRING
        if (dtype.equals(StringCell.TYPE)) {

            return new StringCell(value.toString());
        } 
        
        // DATE/TIME
        /*if (dtype.equals(DateAndTimeCell.TYPE)) {
        	Date d = new Date()
            Date date = (Date) value;
            Calendar cal = GregorianCalendar.getInstance();
            cal.setTime(date);

            return new DateAndTimeCell(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH));
        } */
        return null;
    }


    public static void main(String[] args) {
        isWindowsPlatform();

        isMacOSPlatform();
    }
}