org.apache.accumulo.server.replication.ReplicaSystemFactory.java Source code

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Here is the source code for org.apache.accumulo.server.replication.ReplicaSystemFactory.java

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/*
 * 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.accumulo.server.replication;

import static java.util.Objects.requireNonNull;

import java.util.Map.Entry;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.Maps;

/**
 *
 */
public class ReplicaSystemFactory {
    private static final Logger log = LoggerFactory.getLogger(ReplicaSystemFactory.class);

    /**
     * @param value
     *          {@link ReplicaSystem} implementation class name
     * @return A {@link ReplicaSystem} object from the given name
     */
    public ReplicaSystem get(String value) {
        final Entry<String, String> entry = parseReplicaSystemConfiguration(value);

        try {
            Class<?> clz = Class.forName(entry.getKey());

            if (ReplicaSystem.class.isAssignableFrom(clz)) {
                Object o = clz.newInstance();
                ReplicaSystem rs = (ReplicaSystem) o;
                rs.configure(entry.getValue());
                return rs;
            }

            throw new IllegalArgumentException("Class is not assignable to ReplicaSystem: " + entry.getKey());
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
            log.error("Error creating ReplicaSystem object", e);
            throw new IllegalArgumentException(e);
        }
    }

    /**
     * Parse the configuration value for a peer into its components: {@link ReplicaSystem} class name and configuration string.
     *
     * @param value
     *          The configuration value for a replication peer.
     * @return An entry where the set is the replica system name and the value is the configuration string.
     */
    public Entry<String, String> parseReplicaSystemConfiguration(String value) {
        requireNonNull(value);

        int index = value.indexOf(',');
        if (-1 == index) {
            throw new IllegalArgumentException(
                    "Expected comma separator between replication system name and configuration");
        }

        String name = value.substring(0, index);
        String configuration = value.substring(index + 1);
        return Maps.immutableEntry(name, configuration);
    }

    /**
     * Generate the configuration value for a {@link ReplicaSystem} in the instance properties
     *
     * @param system
     *          The desired ReplicaSystem to use
     * @param configuration
     *          Configuration string for the desired ReplicaSystem
     * @return Value to set for peer configuration in the instance
     */
    public static String getPeerConfigurationValue(Class<? extends ReplicaSystem> system, String configuration) {
        String systemName = system.getName() + ",";
        if (null == configuration) {
            return systemName;
        }

        return systemName + configuration;
    }
}