package org.andromda.core.common;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
/**
* A class used for converting simple types to other types (i.e.
* java.lang.String -> java.lang.Integer, etc).
*
* @author Chad Brandon
*/
public class Converter
{
/**
* The prefix of the 'valueOf' method available on wrapper classes.
*/
private static final String VALUE_OF_METHOD_NAME = "valueOf";
/**
* Attempts to convert the <code>object</code> to the <code>expectedType</code>.
*
* @param object the object to convert.
* @param expectedType the type to which it should be converted.
* @return the converted object
*/
public static Object convert(
Object object,
Class expectedType)
{
try
{
if (expectedType == String.class)
{
object = object.toString();
}
else if (expectedType == Class.class)
{
object = ClassUtils.loadClass(object.toString());
}
else
{
final Class originalType = expectedType;
if (expectedType.isPrimitive())
{
expectedType = (Class)primitiveWrappers.get(expectedType);
}
Method method = null;
try
{
method = expectedType.getDeclaredMethod(
VALUE_OF_METHOD_NAME,
new Class[] {object.getClass()});
object = method.invoke(
expectedType,
new Object[] {object});
}
catch (final NoSuchMethodException exception)
{
// - ignore
}
// - if we couldn't find the method try with the constructor
if (method == null)
{
Constructor constructor;
try
{
constructor = expectedType.getConstructor(new Class[] {originalType});
object = constructor.newInstance(new Object[] {object});
}
catch (final NoSuchMethodException exception)
{
throw new IntrospectorException("Could not convert '" + object + "' to type '" +
expectedType.getName() + "'");
}
}
}
}
catch (final Throwable throwable)
{
throw new IntrospectorException(throwable);
}
return object;
}
/**
* Stores each primitive and its associated wrapper class.
*/
private static final Map primitiveWrappers = new HashMap();
/**
* Initialize the primitiveWrappers.
*/
static
{
primitiveWrappers.put(
boolean.class,
Boolean.class);
primitiveWrappers.put(
int.class,
Integer.class);
primitiveWrappers.put(
long.class,
Long.class);
primitiveWrappers.put(
short.class,
Short.class);
primitiveWrappers.put(
byte.class,
Byte.class);
primitiveWrappers.put(
float.class,
Float.class);
primitiveWrappers.put(
double.class,
Double.class);
primitiveWrappers.put(
char.class,
Character.class);
}
}