co.cask.cdap.api.dataset.DatasetProperties.java Source code

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Here is the source code for co.cask.cdap.api.dataset.DatasetProperties.java

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/*
 * Copyright  2014 Cask Data, 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 co.cask.cdap.api.dataset;

import com.google.common.base.Joiner;
import com.google.common.base.Objects;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Maps;

import java.util.Collections;
import java.util.Map;

/**
 * Dataset instance properties.
 */
public final class DatasetProperties {

    /**
     * Empty properties.
     */
    public static final DatasetProperties EMPTY = new DatasetProperties(Collections.<String, String>emptyMap());

    /**
     * Schema property. Not all datasets support schema.
     */
    public static final String SCHEMA = "schema";

    private final Map<String, String> properties;

    private DatasetProperties(Map<String, String> properties) {
        this.properties = ImmutableMap.copyOf(properties);
    }

    public static Builder builder() {
        return new Builder();
    }

    /**
     * @return properties of the dataset instance
     */
    public Map<String, String> getProperties() {
        return Collections.unmodifiableMap(properties);
    }

    @Override
    public String toString() {
        return Objects.toStringHelper(this)
                .add("properties", Joiner.on(",").withKeyValueSeparator("=").join(properties)).toString();
    }

    /**
     * A Builder to construct DatasetProperties instances.
     */
    public static class Builder {
        private Map<String, String> properties = Maps.newHashMap();

        protected Builder() {
        }

        /**
         * Adds a property.
         * @param key the name of the property
         * @param value the value of the property
         * @return this builder object to allow chaining
         */
        public Builder add(String key, String value) {
            this.properties.put(key, value);
            return this;
        }

        /**
         * Adds a property.
         * @param key the name of the property
         * @param value the value of the property
         * @return this builder object to allow chaining
         */
        public Builder add(String key, int value) {
            this.properties.put(key, String.valueOf(value));
            return this;
        }

        /**
         * Adds multiple properties.
         * @param properties the map of properties to add
         * @return this builder object to allow chaining
         */
        public Builder addAll(Map<String, String> properties) {
            this.properties.putAll(properties);
            return this;
        }

        /**
         * Create a DatasetProperties from this builder, using the private DatasetProperties
         * constructor.
         */
        public DatasetProperties build() {
            return new DatasetProperties(this.properties);
        }
    }
}