google-nomulus/java/google/registry/tools/params/OptionalParameterConverterValidator.java
Justine Tunney 5012893c1d mv com/google/domain/registry google/registry
This change renames directories in preparation for the great package
rename. The repository is now in a broken state because the code
itself hasn't been updated. However this should ensure that git
correctly preserves history for each file.
2016-05-13 18:55:08 -04:00

47 lines
1.6 KiB
Java

// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
//
// 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.google.domain.registry.tools.params;
import com.google.common.base.Optional;
import com.google.domain.registry.util.TypeUtils.TypeInstantiator;
/**
* Class for parameters that can handle special string "null" or empty values to
* indicate a desire to pass an empty value (i.e. when clearing out nullable
* fields on a resource).
*/
public class OptionalParameterConverterValidator<T, C extends ParameterConverterValidator<T>>
extends ParameterConverterValidator<Optional<T>> {
private static final String NULL_STRING = "null";
ParameterConverterValidator<T> validator = new TypeInstantiator<C>(getClass()){}.instantiate();
@Override
public void validate(String name, String value) {
if (!value.isEmpty() && !value.equals(NULL_STRING)) {
validator.validate(name, value);
}
}
@Override
public final Optional<T> convert(String value) {
if (value.equals(NULL_STRING) || value.isEmpty()) {
return Optional.absent();
} else {
return Optional.of(validator.convert(value));
}
}
}