com.sharksharding.util.sequence.mysql.CreateMysqlSequenceId Maven / Gradle / Ivy
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/*
* Copyright 2015-2101 gaoxianglong
*
* 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.sharksharding.util.sequence.mysql;
import java.sql.SQLException;
import java.util.concurrent.ConcurrentHashMap;
import com.sharksharding.exception.SequenceIdException;
import com.sharksharding.util.sequence.CreateSequenceIdServiceImpl;
/**
* 生成基于Mysql的SequenceId
*
* @author JohnGao
*
* @version 1.3.5
*/
public class CreateMysqlSequenceId extends CreateSequenceIdServiceImpl {
private CreateSequenceIdDao createUserNameDao;
private StringBuffer str;
private ConcurrentHashMap useDataMap;
private ConcurrentHashMap surplusDataMap;
private long memData;
public CreateMysqlSequenceId() {
str = new StringBuffer();
useDataMap = new ConcurrentHashMap();
surplusDataMap = new ConcurrentHashMap();
createUserNameDao = new CreateSequenceIdDaoImpl();
}
@Override
public long getSequenceId(int idcNum, int type, long memData) {
long sequenceId = -1;
/* 避免在并发环境下出现线程安全，则添加同步对象锁 */
synchronized (this) {
if (null != createUserNameDao) {
this.memData = memData;
/* idc机房编码数据长度必须为3位,type数据长度必须为2位 */
if (3 == String.valueOf(idcNum).length() && 2 == String.valueOf(type).length()) {
try {
/* 根据指定的类别从内存中获取剩余的占位数量 */
Integer surplusData = surplusDataMap.get(type);
if (null != surplusData) {
if (0 < surplusData) {
surplusDataMap.put(type, --surplusData);
Long useData = useDataMap.get(type);
if (null == useData) {
useData = createUserNameDao.queryUseDatabyType(type);
useDataMap.put(type, useData);
transactionManager();
}
/* 根据指定规则创建唯一的SequenceId */
sequenceId = createSequenceId(useData - surplusData, idcNum, type);
} else {
/* 生成当前占位数据 */
Long useData = createUseData();
surplusData = (int) memData;
/* 根据指定的类别更新当前占位数量 */
createUserNameDao.changeUseData(type, useData);
surplusDataMap.put(type, --surplusData);
useDataMap.put(type, useData);
transactionManager();
sequenceId = createSequenceId(useData - surplusData, idcNum, type);
}
} else {
Long useData = createUseData();
surplusData = (int) memData;
if (null != createUserNameDao.queryUseDatabyType(type)) {
createUserNameDao.changeUseData(type, useData);
} else {
createUserNameDao.insertSequenceId(type, useData);
}
surplusDataMap.put(type, --surplusData);
useDataMap.put(type, useData);
transactionManager();
sequenceId = createSequenceId(useData - surplusData, idcNum, type);
}
} catch (Exception e) {
try {
if (null != CreateSequenceIdDaoImpl.conn && !CreateSequenceIdDaoImpl.conn.isClosed()) {
CreateSequenceIdDaoImpl.conn.rollback();
}
} catch (SQLException e1) {
e1.printStackTrace();
}
throw new SequenceIdException("create sequenceid fail" + e.getMessage());
} finally {
try {
if (null != CreateSequenceIdDaoImpl.conn && !CreateSequenceIdDaoImpl.conn.isClosed()) {
DBConnectionManager.close(CreateSequenceIdDaoImpl.conn);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
} else {
throw new SequenceIdException("idc length must be equal to 3,type length must be equal to 2");
}
}
}
return sequenceId;
}
/**
* 进行事物传播特性控制的事物管理
*
* @author gaoxianglong
*
* @throws SQLException
*
* @return void
*/
private void transactionManager() throws SQLException {
CreateSequenceIdDaoImpl.conn.commit();
}
/**
* 生成当前占位数据
*
* @author gaoxianglong
*
* @throws Exception
*
* @return long 返回生成的当前占位数据
*/
private long createUseData() throws Exception {
/* 获取当前最大的占位数据 */
Long useData = createUserNameDao.queryMaxUseData();
return null != useData ? useData += memData : memData;
}
/**
* 根据指定规则创建唯一的userName
*
* @author gaoxianglong
*
* @param id
* 唯一序列
*
* @param idcNum
* IDC机房编码, 用于区分不同的IDC机房,3位数字长度
*
* @param type
* 业务类别,2位数字长度
*
* @return long 返回生成的19位数字长度的sequenceId
*/
private long createSequenceId(Long id, int idcNum, int type) {
if (null != str)
str.delete(0, str.length());
final int length = 14 - String.valueOf(id).length();
/* 唯一序列高位补0 */
for (int i = 0; i < length; i++)
str.append(0);
str.append(id);
str.insert(0, idcNum);
str.insert(3, type);
return Long.parseLong(str.toString());
}
}