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
   *
   *     https://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.avro.path;
  
  import org.apache.avro.Schema;
  import org.apache.avro.util.SchemaUtil;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * a {@link ClassCastException} with extra fields used to trace back the path to
   * a bad value through an object graph
   */
  public class TracingClassCastException extends ClassCastException implements PathTracingException<ClassCastException> {
    private final ClassCastException cause;
    private final Object datum;
    private final Schema expected;
    private final boolean customCoderUsed;
    private final List<PathElement> reversePath;
  
    public TracingClassCastException(ClassCastException cause, Object datum, Schema expected, boolean customCoderUsed) {
      this.cause = cause;
      this.datum = datum;
      this.expected = expected;
      this.customCoderUsed = customCoderUsed;
      this.reversePath = new ArrayList<>(3); // assume short
    }
  
    @Override
    public void tracePath(PathElement step) {
      reversePath.add(step);
    }
  
    @Override
    public synchronized ClassCastException getCause() {
      return cause;
    }
  
    /**
     * @return a hopefully helpful error message
     */
    @Override
    public ClassCastException summarize(Schema root) {
      StringBuilder sb = new StringBuilder();
      sb.append("value ").append(SchemaUtil.describe(datum));
      sb.append(" cannot be cast to expected type ").append(SchemaUtil.describe(expected));
      if (reversePath == null || reversePath.isEmpty()) {
        // very simple "shallow" NPE, no nesting at all, or custom coders used means we
        // have no data
        if (customCoderUsed) {
          sb.append(". No further details available as custom coders were used");
        }
      } else {
        sb.append(" at ");
        if (root != null) {
          sb.append(SchemaUtil.describe(root));
        }
        for (int i = reversePath.size() - 1; i >= 0; i--) {
          PathElement step = reversePath.get(i);
          sb.append(step.toString());
        }
      }
      ClassCastException summary = new ClassCastException(sb.toString());
      summary.initCause(cause);
      return summary;
    }
  }
  