common/src/main/java/org/apache/drill/common/scanner/persistence/AnnotatedClassDescriptor.java

/*
 * 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.drill.common.scanner.persistence;

import java.util.Collections;
import java.util.List;
import java.util.Map;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

/**
 * describe a class that was annotated with one of the configured annotations
 */
public final class AnnotatedClassDescriptor {

  private final String className;
  private final List<AnnotationDescriptor> annotations;
  private final List<FieldDescriptor> fields;
  private final Map<String, AnnotationDescriptor> annotationMap;

  @JsonCreator public AnnotatedClassDescriptor(
      @JsonProperty("className") String className,
      @JsonProperty("annotations") List<AnnotationDescriptor> annotations,
      @JsonProperty("fields") List<FieldDescriptor> fields) {
    this.className = className;
    this.annotations = Collections.unmodifiableList(annotations);
    this.fields = Collections.unmodifiableList(fields);
    this.annotationMap = AnnotationDescriptor.buildAnnotationsMap(annotations);
  }

  /**
   * @return the fully qualified name of the annotated class
   */
  public String getClassName() {
    return className;
  }

  /**
   * @return the class level annotations
   */
  public List<AnnotationDescriptor> getAnnotations() {
    return annotations;
  }

  /**
   * @return the fields declared by the class
   */
  public List<FieldDescriptor> getFields() {
    return fields;
  }

  /**
   * @param clazz the annotation type
   * @return the corresponding annotation descriptor
   */
  public AnnotationDescriptor getAnnotation(Class<?> clazz) {
    return annotationMap.get(clazz.getName());
  }

  /**
   * @param clazz the annotation type
   * @return a bytecode based implementation of the annotation
   */
  public <T> T getAnnotationProxy(Class<T> clazz) {
    final AnnotationDescriptor annotationDescriptor = getAnnotation(clazz);
    if (annotationDescriptor == null) {
      return null;
    }
    return annotationDescriptor.getProxy(clazz);
  }

  @Override
  public String toString() {
    return "Function [className=" + className + ", annotations=" + annotations
        + ", fields=" + fields + "]";
  }
}