content: /*
   * 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.beam.sdk.extensions.sql.impl.udf;
  
  import java.lang.reflect.Method;
  import java.util.Arrays;
  import java.util.List;
  import java.util.Map;
  import java.util.stream.Collectors;
  
  /** BeamBuiltinFunctionClass interface. */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  public abstract class BeamBuiltinFunctionProvider {
    public Map<String, List<Method>> getBuiltinMethods() {
      List<Method> methods = Arrays.asList(getClass().getMethods());
      return methods.stream()
          .filter(BeamBuiltinFunctionProvider::isUDF)
          .collect(
              Collectors.groupingBy(method -> method.getDeclaredAnnotation(UDF.class).funcName()));
    }
  
    private static boolean isUDF(Method m) {
      return m.getDeclaredAnnotation(UDF.class) != null;
    }
  }
  