import java.util.*;
import java.lang.reflect.*;

public class ConvertUtil {
    private static Map<Class,Class> primitiveMap = new HashMap<Class,Class>();
    static {
	primitiveMap.put(boolean.class, Boolean.class);
	primitiveMap.put(byte.class, Byte.class);
	primitiveMap.put(char.class, Character.class);
	primitiveMap.put(short.class, Short.class);
	primitiveMap.put(int.class, Integer.class);
	primitiveMap.put(long.class, Long.class);
	primitiveMap.put(float.class, Float.class);
	primitiveMap.put(double.class, Double.class);
    }

    /**
     * Best try to convert string to destination class. If destClass is one of
     * the supported primitive classes, an object of that type is returned. 
     * Otherwise, the original string is returned.
     */
    public static Object convert(String value, Class<?> destClass) {
	if ((value == null) || "".equals(value)) {
	    return value;
	}

	if (destClass.isPrimitive()) {
	    destClass = primitiveMap.get(destClass);
	}

	try {
	    Method m = destClass.getMethod("valueOf", String.class);
	    int mods = m.getModifiers();
	    if (Modifier.isStatic(mods) && Modifier.isPublic(mods)) {
		return m.invoke(null, value);
	    }
	}
	catch (NoSuchMethodException e) {
	    if (destClass == Character.class) {
		return Character.valueOf(value.charAt(0));
	    }
	}
	catch (IllegalAccessException e) {
	    // this won't happen
	}
	catch (InvocationTargetException e) {
	    // when this happens, the string cannot be converted to the intended type
            // we are ignoring it here - the original string will be returned.
            // But it can be re-thrown if desired!
	}

	return value;
    }

    public static void main(String[] args) throws ClassNotFoundException {
	System.out.printf("Convert to boolean: %s, %s\n", 
	    "true",
	    ConvertUtil.convert("true", boolean.class).getClass().getName()
	);
	System.out.printf("Convert to byte: %s, %s\n", 
	    "12",
	    ConvertUtil.convert("12", Byte.class).getClass().getName()
	);
	System.out.printf("Convert to char: %s, %s\n", 
	    "hello",
	    ConvertUtil.convert("hello", Character.class).getClass().getName()
	);
	System.out.printf("Convert to short: %s, %s\n", 
	    "34",
	    ConvertUtil.convert("34", short.class).getClass().getName()
	);
	System.out.printf("Convert to int: %s, %s\n", 
	    "90123456",
	    ConvertUtil.convert("90123456", int.class).getClass().getName()
	);
	System.out.printf("Convert to long: %s, %s\n", 
	    "current time",
	    ConvertUtil.convert("" + System.currentTimeMillis(), Long.class).getClass().getName()
	);
	System.out.printf("Convert to float: %s, %s\n", 
	    "12.34",
	    ConvertUtil.convert("12.34", Float.class).getClass().getName()
	);
	System.out.printf("Convert to double: %s, %s\n", 
	    "3512895.435423",
	    ConvertUtil.convert("3512895.435423", Class.forName("java.lang.Double")).getClass().getName()
	);
    }
}

public class DateConverter {
    public static Date valueOf(String dateStr) {
        // parse date string and return java.util.Date object
    }
}

Date d = (Date) ConvertUtil.convert("10/12/2010", Class.forName("DateConverter"));