/*
* Copyright 2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.data.hadoop.store.expression;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.springframework.expression.AccessException;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.MethodExecutor;
import org.springframework.expression.TypedValue;
/**
* A {@link MethodExecutor} handling formatting using a {@link SimpleDateFormat}.
*
* @author Janne Valkealahti
* @author Rodrigo Meneses
*
*/
public class DateFormatMethodExecutor implements MethodExecutor {
private final static String DEFAULT_FORMAT = "yyyy-MM-dd";
private String key;
/**
* Instantiates a new date format method executor.
*/
public DateFormatMethodExecutor() {
}
/**
* Instantiates a new date format method executor.
*
* @param key the key for timestamp
*/
public DateFormatMethodExecutor(String key) {
this.key = key;
}
@Override
public TypedValue execute(EvaluationContext context, Object target, Object... arguments) throws AccessException {
if (key == null) {
SimpleDateFormat format = new SimpleDateFormat((String)arguments[0]);
//if first argument is Long, then we assume it's a timestamp in milliseconds type format
//first argument can also be a Date itself
if (arguments[1] instanceof Long || arguments[1] instanceof Date) {
return new TypedValue(format.format(arguments[1]));
}
//if the argument is a String, then assume it's a Date represented as a String.
if (arguments[1] instanceof String) {
//Assume it's in default formay yyyMMdd
SimpleDateFormat fromFormat = new SimpleDateFormat(DEFAULT_FORMAT);
//if the third argument is present, use it as the from date format
if (arguments.length == 3 && arguments[2] instanceof String)
fromFormat = new SimpleDateFormat((String)arguments[2]);
try {
Date parsedDate = fromFormat.parse((String) arguments[1]);
return new TypedValue(format.format(parsedDate));
} catch (ParseException e) {
throw new AccessException("Unable to format", e);
}
}
return new TypedValue(format.format((Long)arguments[1]));
}
throw new AccessException("Unable to format");
}
/**
* Gets the key for timestamp if defined.
*
* @return the timestamp key
*/
protected String getKey() {
return key;
}
}