org.apache.flink.api.java.ExecutionPlanUtil Maven / Gradle / Ivy
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* 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.flink.api.java;
import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.Plan;
import static org.apache.flink.util.Preconditions.checkNotNull;
/**
* A utility for extracting an execution plan (as JSON) from a {@link Plan}.
*/
@Internal
public class ExecutionPlanUtil {
private static final String PLAN_GENERATOR_CLASS_NAME = "org.apache.flink.optimizer.plandump.ExecutionPlanJSONGenerator";
/**
* Extracts the execution plan (as JSON) from the given {@link Plan}.
*/
public static String getExecutionPlanAsJSON(Plan plan) {
checkNotNull(plan);
ExecutionPlanJSONGenerator jsonGenerator = getJSONGenerator();
return jsonGenerator.getExecutionPlan(plan);
}
private static ExecutionPlanJSONGenerator getJSONGenerator() {
Class planGeneratorClass = loadJSONGeneratorClass(
PLAN_GENERATOR_CLASS_NAME);
try {
return planGeneratorClass.getConstructor().newInstance();
} catch (Throwable t) {
throw new RuntimeException("An error occurred while loading the plan generator ("
+ PLAN_GENERATOR_CLASS_NAME + ").", t);
}
}
private static Class loadJSONGeneratorClass(String className) {
try {
Class generatorClass = Class.forName(className);
return generatorClass.asSubclass(ExecutionPlanJSONGenerator.class);
} catch (ClassNotFoundException cnfe) {
throw new RuntimeException("Could not load the plan generator class (" + className
+ "). Do you have the 'flink-optimizer' project in your dependencies?");
} catch (Throwable t) {
throw new RuntimeException(
"An error occurred while loading the plan generator (" + className + ").",
t);
}
}
/**
* Internal interface for the JSON plan generator that has to reside in the optimizer package.
* We load the actual subclass using reflection.
*/
@Internal
public interface ExecutionPlanJSONGenerator {
/**
* Returns the execution plan as a JSON string.
*/
String getExecutionPlan(Plan plan);
}
}