com.cloudera.cdk.maven.plugins.CreateDatasetMojo.java Source code

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Here is the source code for com.cloudera.cdk.maven.plugins.CreateDatasetMojo.java

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/**
 * Copyright 2013 Cloudera Inc.
 *
 * 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 com.cloudera.cdk.maven.plugins;

import com.cloudera.cdk.data.DatasetDescriptor;
import com.cloudera.cdk.data.DatasetRepository;
import com.cloudera.cdk.data.Formats;
import com.cloudera.cdk.data.impl.Accessor;
import com.google.common.io.Resources;
import java.io.File;
import java.io.IOException;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;

/**
 * Create a named dataset whose entries conform to a defined schema.
 */
@Mojo(name = "create-dataset", requiresProject = false)
public class CreateDatasetMojo extends AbstractDatasetMojo {

    /**
     * The name of the dataset to create.
     */
    @Parameter(property = "cdk.datasetName", required = true)
    private String datasetName;

    /**
     * The file containing the Avro schema. If no file with the specified name is found
     * on the local filesystem, then the classpath is searched for a matching resource.
     */
    @Parameter(property = "cdk.avroSchemaFile", required = true)
    private String avroSchemaFile;

    /**
     * The file format (avro or parquet).
     */
    @Parameter(property = "cdk.format")
    private String format = Formats.AVRO.getName();

    /**
     * The partition expression, in JEXL format (experimental).
     */
    @Parameter(property = "cdk.partitionExpression")
    private String partitionExpression;

    @Override
    public void execute() throws MojoExecutionException, MojoFailureException {
        DatasetRepository repo = getDatasetRepository();

        DatasetDescriptor.Builder descriptorBuilder = new DatasetDescriptor.Builder();
        File avroSchema = new File(avroSchemaFile);
        try {
            if (avroSchema.exists()) {
                descriptorBuilder.schema(avroSchema);
            } else {
                descriptorBuilder.schema(Resources.getResource(avroSchemaFile).openStream());
            }
        } catch (IOException e) {
            throw new MojoExecutionException("Problem while reading file " + avroSchemaFile, e);
        }

        if (format.equals(Formats.AVRO.getName())) {
            descriptorBuilder.format(Formats.AVRO);
        } else if (format.equals(Formats.PARQUET.getName())) {
            descriptorBuilder.format(Formats.PARQUET);
        } else {
            throw new MojoExecutionException("Unrecognized format: " + format);
        }

        if (partitionExpression != null) {
            descriptorBuilder.partitionStrategy(Accessor.getDefault().fromExpression(partitionExpression));
        }

        repo.create(datasetName, descriptorBuilder.get());
    }
}