org.apache.drill.jdbc.StorageEngines.java Source code

Introduction

Here is the source code for org.apache.drill.jdbc.StorageEngines.java

Source

/**
 * 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.drill.jdbc;

import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.drill.common.config.DrillConfig;
import org.apache.drill.common.logical.StorageEngineConfig;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Charsets;
import com.google.common.io.Resources;

public class StorageEngines implements Iterable<Map.Entry<String, StorageEngineConfig>> {

    private Map<String, StorageEngineConfig> storage;

    @JsonCreator
    public StorageEngines(@JsonProperty("storage") Map<String, StorageEngineConfig> storage) {
        this.storage = storage;
    }

    public static void main(String[] args) throws Exception {
        DrillConfig config = DrillConfig.create();
        String data = Resources.toString(Resources.getResource("storage-engines.json"), Charsets.UTF_8);
        StorageEngines se = config.getMapper().readValue(data, StorageEngines.class);
        System.out.println(se);
    }

    @Override
    public String toString() {
        final int maxLen = 10;
        return "StorageEngines [storage=" + (storage != null ? toString(storage.entrySet(), maxLen) : null) + "]";
    }

    @Override
    public Iterator<Entry<String, StorageEngineConfig>> iterator() {
        return storage.entrySet().iterator();
    }

    private String toString(Collection<?> collection, int maxLen) {
        StringBuilder builder = new StringBuilder();
        builder.append("[");
        int i = 0;
        for (Iterator<?> iterator = collection.iterator(); iterator.hasNext() && i < maxLen; i++) {
            if (i > 0)
                builder.append(", ");
            builder.append(iterator.next());
        }
        builder.append("]");
        return builder.toString();
    }

}