com.rapiddweller.common.validator.UniqueValidator Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of rd-lib-common Show documentation

'rapiddweller Common' is an open source Java library forked from Databene Commons by Volker Bergmann. It provides extensions to the Java core library by utility classes, abstract concepts and concrete implementations.

There is a newer version: 2.0.1-jdk-11

Show newest version

/*
 * Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
 * 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.rapiddweller.common.validator;

import com.rapiddweller.common.Resettable;
import com.rapiddweller.common.Validator;

import java.util.HashSet;
import java.util.Set;

/**
 * Validator implementation that requires each argument
 * of consecutive calls to the valid() method to be unique.
 * Created: 20.11.2007 09:55:16
 *
 * @param  the object type to be validated
 * @author Volker Bergmann
 */
public class UniqueValidator implements Validator, Resettable {

  private final Set instances = new HashSet<>();

  @Override
  public boolean valid(E object) {
    if (instances.contains(object)) {
      return false;
    }
    instances.add(object);
    return true;
  }

  @Override
  public void reset() {
    instances.clear();
  }

  @Override
  public String toString() {
    return getClass().getSimpleName();
  }

}