/*
* 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.coders;
/**
* The exception thrown when a {@link CoderRegistry} or {@link CoderProvider} cannot
* provide a {@link Coder} that has been requested.
*/
public class CannotProvideCoderException extends Exception {
private final ReasonCode reason;
public CannotProvideCoderException(String message) {
this(message, ReasonCode.UNKNOWN);
}
public CannotProvideCoderException(String message, ReasonCode reason) {
super(message);
this.reason = reason;
}
public CannotProvideCoderException(String message, Throwable cause) {
this(message, cause, ReasonCode.UNKNOWN);
}
public CannotProvideCoderException(String message, Throwable cause, ReasonCode reason) {
super(message, cause);
this.reason = reason;
}
public CannotProvideCoderException(Throwable cause) {
this(cause, ReasonCode.UNKNOWN);
}
public CannotProvideCoderException(Throwable cause, ReasonCode reason) {
super(cause);
this.reason = reason;
}
/**
* @return the reason that Coder inference failed.
*/
public ReasonCode getReason() {
return reason;
}
/**
* Returns the inner-most {@link CannotProvideCoderException} when they are deeply nested.
*
* <p>For example, if a coder for {@code List<KV<Integer, Whatsit>>} cannot be provided because
* there is no known coder for {@code Whatsit}, the root cause of the exception should be a
* CannotProvideCoderException with details pertinent to {@code Whatsit}, suppressing the
* intermediate layers.
*/
public Throwable getRootCause() {
Throwable cause = getCause();
if (cause == null) {
return this;
} else if (!(cause instanceof CannotProvideCoderException)) {
return cause;
} else {
return ((CannotProvideCoderException) cause).getRootCause();
}
}
/**
* Indicates the reason that {@link Coder} inference failed.
*/
public enum ReasonCode {
/**
* The reason a coder could not be provided is unknown or does have an established
* {@link ReasonCode}.
*/
UNKNOWN,
/**
* The reason a coder could not be provided is type erasure, for example when requesting
* coder inference for a {@code List<T>} where {@code T} is unknown.
*/
TYPE_ERASURE
}
}