/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.flink.graph.drivers.parameter;
/**
* A {@link Parameter} with a default value.
*/
public abstract class SimpleParameter<T>
implements Parameter<T> {
protected final String name;
protected boolean hasDefaultValue = false;
protected T defaultValue;
protected T value;
/**
* Set the parameter name and add this parameter to the list of parameters
* stored by owner.
*
* @param owner the {@link Parameterized} using this {@link Parameter}
* @param name the parameter name
*/
protected SimpleParameter(ParameterizedBase owner, String name) {
this.name = name;
owner.addParameter(this);
}
/**
* Set the default value, used if no value is set by the command-line
* configuration.
*
* @param defaultValue the default value
* @return this
*/
protected SimpleParameter setDefaultValue(T defaultValue) {
this.hasDefaultValue = true;
this.defaultValue = defaultValue;
return this;
}
@Override
public String getUsage() {
String option = "--" + name + " " + name.toUpperCase();
return hasDefaultValue ? "[" + option + "]" : option;
}
@Override
public T getValue() {
return value;
}
}