aljoscha commented on a change in pull request #9690: [FLINK-14067] Decouple PlanExecutor from JSON plan generation URL: https://github.com/apache/flink/pull/9690#discussion_r325058423
########## File path: flink-java/src/main/java/org/apache/flink/api/java/ExecutionPlanUtil.java ########## @@ -0,0 +1,76 @@ +/* + * 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; + +/** + * 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) { + ExecutionPlanJSONGenerator jsonGenerator = getJSONGenerator(); + return jsonGenerator.getExecutionPlan(plan); + } + + private static ExecutionPlanJSONGenerator getJSONGenerator() { + Class<? extends ExecutionPlanJSONGenerator> 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<? extends ExecutionPlanJSONGenerator> loadJSONGeneratorClass(String className) { + try { + Class<?> generatorClass = Class.forName( + "org.apache.flink.optimizer.plandump.ExecutionPlanJSONGenerator"); + 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 { + String getExecutionPlan(Plan plan); Review comment: adding javadoc ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
