net.hasor.utils.json.JSONEnumConvertor Maven / Gradle / Ivy
// ========================================================================
// Copyright (c) 2004-2009 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
package net.hasor.utils.json;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.logging.Logger;
/* ------------------------------------------------------------ */
/**
* Convert an {@link Enum} to JSON.
* If fromJSON is true in the constructor, the JSON generated will
* be of the form {class="com.acme.TrafficLight",value="Green"}
* If fromJSON is false, then only the string value of the enum is generated.
*/
public class JSONEnumConvertor implements JSON.Convertor {
protected final static Logger logger = Logger.getLogger(JSONEnumConvertor.class.getName());
private boolean _fromJSON;
private Method _valueOf;
{
try {
Class e = Loader.loadClass(getClass(), "java.lang.Enum");
_valueOf = e.getMethod("valueOf", new Class[] { Class.class, String.class });
} catch (Exception e) {
throw new RuntimeException("!Enums", e);
}
}
public JSONEnumConvertor() {
this(false);
}
public JSONEnumConvertor(boolean fromJSON) {
_fromJSON = fromJSON;
}
public Object fromJSON(Map map) {
if (!_fromJSON)
throw new UnsupportedOperationException();
try {
Class c = Loader.loadClass(getClass(), (String) map.get("class"));
return _valueOf.invoke(null, new Object[] { c, map.get("value") });
} catch (Exception e) {
logger.warning(e.getMessage());
}
return null;
}
public void toJSON(Object obj, JSON.Output out) {
if (_fromJSON) {
out.addClass(obj.getClass());
out.add("value", obj.toString());
} else {
out.add(obj.toString());
}
}
}