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.cassandra.config;
  
  import java.beans.IntrospectionException;
  import java.beans.Introspector;
  import java.beans.PropertyDescriptor;
  import java.lang.reflect.Field;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.lang.reflect.Modifier;
  import java.util.HashMap;
  import java.util.Map;
  
  import com.fasterxml.jackson.annotation.JsonIgnore;
  import org.yaml.snakeyaml.error.YAMLException;
  import org.yaml.snakeyaml.introspector.FieldProperty;
  import org.yaml.snakeyaml.introspector.MethodProperty;
  import org.yaml.snakeyaml.introspector.Property;
  
  import static org.apache.cassandra.utils.FBUtilities.camelToSnake;
  
  public class DefaultLoader implements Loader
  {
      @Override
      public Map<String, Property> getProperties(Class<?> root)
      {
          Map<String, Property> properties = new HashMap<>();
          for (Class<?> c = root; c != null; c = c.getSuperclass())
          {
              for (Field f : c.getDeclaredFields())
              {
                  String name = camelToSnake(f.getName());
                  int modifiers = f.getModifiers();
                  if (!Modifier.isStatic(modifiers)
                      && !f.isAnnotationPresent(JsonIgnore.class)
                      && !Modifier.isTransient(modifiers)
                      && Modifier.isPublic(modifiers)
                      && !properties.containsKey(name))
                      properties.put(name, new FieldProperty(f));
              }
          }
          try
          {
              PropertyDescriptor[] descriptors = Introspector.getBeanInfo(root).getPropertyDescriptors();
              if (descriptors != null)
              {
                  for (PropertyDescriptor d : descriptors)
                  {
                      String name = camelToSnake(d.getName());
                      Method writeMethod = d.getWriteMethod();
                      // if the property can't be written to, then ignore it
                      if (writeMethod == null || writeMethod.isAnnotationPresent(JsonIgnore.class))
                          continue;
                      // if read method exists, override the field version in case get/set does validation
                      if (properties.containsKey(name) && (d.getReadMethod() == null || d.getReadMethod().isAnnotationPresent(JsonIgnore.class)))
                          continue;
                      d.setName(name);
                      properties.put(name, new MethodPropertyPlus(d));
                  }
              }
          }
          catch (IntrospectionException e)
          {
              throw new RuntimeException(e);
          }
          return properties;
      }
  
      /**
       * .get() acts differently than .set() and doesn't do a good job showing the cause of the failure, this
       * class rewrites to make the errors easier to reason with.
       */
      private static class MethodPropertyPlus extends MethodProperty
      {
          private final Method readMethod;
  
          public MethodPropertyPlus(PropertyDescriptor property)
          {
              super(property);
              this.readMethod = property.getReadMethod();
          }
  
          @Override
          public Object get(Object object)
          {
              if (!isReadable())
                  throw new YAMLException("No readable property '" + getName() + "' on class: " + object.getClass().getName());
  
              try
              {
                  return readMethod.invoke(object);
              }
              catch (IllegalAccessException e)
              {
                  throw new YAMLException("Unable to find getter for property '" + getName() + "' on class " + object.getClass().getName(), e);
              }
              catch (InvocationTargetException e)
              {
                  throw new YAMLException("Failed calling getter for property '" + getName() + "' on class " + object.getClass().getName(), e.getCause());
              }
          }
      }
  }
  