com.netflix.config.StringDerivedProperty Maven / Gradle / Ivy
/**
* Copyright 2014 Netflix, Inc.
*
* 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 com.netflix.config;
import com.google.common.base.Function;
/**
* A property wrapper that can be used to derive any type of data as property value
* from string format.
*
* @author awang
*
* @param Type of the property value
*/
public class StringDerivedProperty extends PropertyWrapper {
protected final Function decoder;
private volatile T derivedValue;
/**
* Create an instance of the property wrapper.
*
* @param decoder the function used to parse the string format into the desired data type.
*/
public StringDerivedProperty(String propName, T defaultValue, Function decoder) {
super(propName, defaultValue);
this.decoder = decoder;
propertyChangedInternal();
}
private final void propertyChangedInternal() {
String stringValue = prop.getString();
if (stringValue == null) {
derivedValue = defaultValue;
} else {
derivedValue = decoder.apply(stringValue);
}
}
@Override
protected final void propertyChanged() {
propertyChangedInternal();
propertyChanged(getValue());
}
@Override
public T getValue() {
return derivedValue;
}
}