com.cloudera.cdk.examples.data.CreateUserDatasetPojo.java Source code

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Here is the source code for com.cloudera.cdk.examples.data.CreateUserDatasetPojo.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.examples.data;

import com.cloudera.data.Dataset;
import com.cloudera.data.DatasetDescriptor;
import com.cloudera.data.DatasetRepository;
import com.cloudera.data.DatasetWriter;
import com.cloudera.data.filesystem.FileSystemDatasetRepository;
import java.io.IOException;
import java.util.Random;
import org.apache.avro.Schema;
import org.apache.avro.reflect.ReflectData;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

/**
 * Create a dataset on the local filesystem and write some {@link User} objects to it.
 */
public class CreateUserDatasetPojo extends Configured implements Tool {

    @Override
    public int run(String[] args) throws IOException {

        // Construct a local filesystem dataset repository rooted at /tmp/data
        FileSystem fs = FileSystem.getLocal(new Configuration());
        Path root = new Path("/tmp/data");
        DatasetRepository repo = new FileSystemDatasetRepository(fs, root);

        // Generate an Avro schema from the User class
        Schema schema = ReflectData.get().getSchema(User.class);

        // Create a dataset of users with the Avro schema in the repository
        DatasetDescriptor descriptor = new DatasetDescriptor.Builder().schema(schema).get();
        Dataset users = repo.create("users", descriptor);

        // Get a writer for the dataset and write some users to it
        DatasetWriter<User> writer = users.getWriter();
        try {
            writer.open();
            String[] colors = { "green", "blue", "pink", "brown", "yellow" };
            Random rand = new Random();
            for (int i = 0; i < 100; i++) {
                User user = new User();
                user.setUsername("user-" + i);
                user.setCreationDate(System.currentTimeMillis());
                user.setFavoriteColor(colors[rand.nextInt(colors.length)]);
                writer.write(user);
            }
        } finally {
            writer.close();
        }

        return 0;
    }

    public static void main(String... args) throws Exception {
        int rc = ToolRunner.run(new CreateUserDatasetPojo(), args);
        System.exit(rc);
    }
}