org.apache.flink.api.java.LocalEnvironment 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.Public;
import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.common.InvalidProgramException;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.configuration.DeploymentOptions;
import static org.apache.flink.util.Preconditions.checkNotNull;
/**
* An {@link ExecutionEnvironment} that runs the program locally, multi-threaded, in the JVM where
* the environment is instantiated.
*
* When this environment is instantiated, it uses a default parallelism of {@code 1}. The default
* parallelism can be set via {@link #setParallelism(int)}.
*
*
Local environments can also be instantiated through {@link
* ExecutionEnvironment#createLocalEnvironment()} and {@link
* ExecutionEnvironment#createLocalEnvironment(int)}. The former version will pick a default
* parallelism equal to the number of hardware contexts in the local machine.
*/
@Public
public class LocalEnvironment extends ExecutionEnvironment {
/** Creates a new local environment. */
public LocalEnvironment() {
this(new Configuration());
}
/**
* Creates a new local environment that configures its local executor with the given
* configuration.
*
* @param config The configuration used to configure the local executor.
*/
public LocalEnvironment(Configuration config) {
super(validateAndGetConfiguration(config));
}
private static Configuration validateAndGetConfiguration(final Configuration configuration) {
if (!ExecutionEnvironment.areExplicitEnvironmentsAllowed()) {
throw new InvalidProgramException(
"The LocalEnvironment cannot be instantiated when running in a pre-defined context "
+ "(such as Command Line Client, Scala Shell, or TestEnvironment)");
}
final Configuration effectiveConfiguration = new Configuration(checkNotNull(configuration));
effectiveConfiguration.set(DeploymentOptions.TARGET, "local");
effectiveConfiguration.set(DeploymentOptions.ATTACHED, true);
return effectiveConfiguration;
}
@Override
public String toString() {
return "Local Environment (parallelism = "
+ (getParallelism() == ExecutionConfig.PARALLELISM_DEFAULT
? "default"
: getParallelism())
+ ").";
}
}