IPIdGenerator.java

/*
 * Copyright 1999-2015 dangdang.com.
 * <p>
 * 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.
 * </p>
 */

package com.dangdang.ddframe.rdb.sharding.id.generator.self;

import com.dangdang.ddframe.rdb.sharding.id.generator.IdGenerator;

import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * 根据机器IP获取工作进程Id,如果线上机器的IP二进制表示的最后10位不重复,建议使用此种方式
 * ,列如机器的IP为192.168.1.108,二进制表示:11000000 10101000 00000001 01101100
 * ,截取最后10位 01 01101100,转为十进制364,设置workerId为364.
 *
 * @author DonneyYoung
 */
public class IPIdGenerator implements IdGenerator {

    private final CommonSelfIdGenerator commonSelfIdGenerator = new CommonSelfIdGenerator();

    static {
        initWorkerId();
    }

    static void initWorkerId() {
        InetAddress address;
        try {
            address = InetAddress.getLocalHost();
        } catch (final UnknownHostException e) {
            throw new IllegalStateException("Cannot get LocalHost InetAddress, please check your network!");
        }
        byte[] ipAddressByteArray = address.getAddress();
        CommonSelfIdGenerator.setWorkerId((long) (((ipAddressByteArray[ipAddressByteArray.length - 2] & 0B11) << Byte.SIZE) + (ipAddressByteArray[ipAddressByteArray.length - 1] & 0xFF)));
    }

    @Override
    public Number generateId() {
        return commonSelfIdGenerator.generateId();
    }
}