azkaban.project.FlowLoaderFactory.java Source code

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Here is the source code for azkaban.project.FlowLoaderFactory.java

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/*
* Copyright 2017 LinkedIn Corp.
*
* Licensed 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 azkaban.project;

import static java.util.Objects.requireNonNull;

import azkaban.Constants;
import azkaban.project.FlowLoaderUtils.DirFilter;
import azkaban.project.FlowLoaderUtils.SuffixFilter;
import azkaban.utils.Props;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Map;
import javax.inject.Inject;
import org.apache.commons.lang.ArrayUtils;
import org.yaml.snakeyaml.Yaml;

/**
 * Factory class to generate flow loaders.
 */
public class FlowLoaderFactory {

    private final Props props;

    /**
     * Instantiates a new Flow loader factory.
     *
     * @param props the props
     */
    @Inject
    public FlowLoaderFactory(final Props props) {
        this.props = requireNonNull(props, "Props is null");
    }

    /**
     * Creates flow loader based on project YAML file inside project directory.
     *
     * @param projectDir the project directory
     * @return the flow loader
     */
    public FlowLoader createFlowLoader(final File projectDir) throws ProjectManagerException {
        if (checkForValidProjectYamlFile(projectDir)) {
            return new DirectoryYamlFlowLoader(this.props);
        } else {
            return new DirectoryFlowLoader(this.props);
        }
    }

    private boolean checkForValidProjectYamlFile(final File projectDir) throws ProjectManagerException {
        final File[] projectFileList = projectDir.listFiles(new SuffixFilter(Constants.PROJECT_FILE_SUFFIX));

        if (projectFileList == null) {
            throw new ProjectManagerException(
                    "Error reading project directory. Input is not a " + "directory or IO error happens.");
        }

        if (ArrayUtils.isNotEmpty(projectFileList)) {
            if (projectFileList.length > 1) {
                throw new ProjectManagerException(
                        "Duplicate project YAML files found in the project " + "directory. Only one is allowed.");
            }

            final Map<String, Object> azkabanProject;
            try (FileInputStream fis = new FileInputStream(projectFileList[0])) {
                azkabanProject = (Map<String, Object>) new Yaml().load(fis);
            } catch (final IOException e) {
                throw new ProjectManagerException("Error reading project YAML file.", e);
            }

            if (azkabanProject == null
                    || !azkabanProject.containsKey(Constants.ConfigurationKeys.AZKABAN_FLOW_VERSION)) {
                throw new ProjectManagerException(
                        "azkaban-flow-version is not specified in the project " + "YAML file.");
            }

            if (azkabanProject.get(Constants.ConfigurationKeys.AZKABAN_FLOW_VERSION)
                    .equals(Constants.AZKABAN_FLOW_VERSION_2_0)) {
                return true;
            } else {
                throw new ProjectManagerException("Invalid azkaban-flow-version in the project YAML file.");
            }
        } else {
            for (final File file : projectDir.listFiles(new DirFilter())) {
                if (checkForValidProjectYamlFile(file)) {
                    return true;
                }
            }
            return false;
        }
    }
}