/*******************************************************************************
 * Copyright 2013 SAP AG
 * 
 * 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.sap.core.odata.core.edm;

import com.sap.core.odata.api.edm.EdmFacets;
import com.sap.core.odata.api.edm.EdmLiteralKind;
import com.sap.core.odata.api.edm.EdmSimpleTypeException;

/**
 * Implementation of the simple type Null.
 * @author SAP AG
 */
public class EdmNull extends AbstractSimpleType {

  private static final EdmNull instance = new EdmNull();

  public static EdmNull getInstance() {
    return instance;
  }

  @Override
  public boolean equals(final Object obj) {
    return this == obj || obj == null;
  }

  @Override
  public int hashCode() {
    return 0;
  }

  @Override
  public Class<?> getDefaultType() {
    return null;
  }

  @Override
  protected <T> T internalValueOfString(final String value, final EdmLiteralKind literalKind, final EdmFacets facets, final Class<T> returnType) throws EdmSimpleTypeException {
    return null;
  }

  @Override
  protected <T> String internalValueToString(final T value, final EdmLiteralKind literalKind, final EdmFacets facets) throws EdmSimpleTypeException {
    return null;
  }

  @Override
  public String toUriLiteral(final String literal) {
    return "null";
  }
}