昨天做了插入的单线程多线程比较，今天做个删除的。
单线程批量删除类代码：
package com.hy.delete.singlethread;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import org.apache.log4j.Logger;
import com.hy.DBParam;
/**
* 多表单线程删除
* Single thread table deleter
* @author 逆火
*
* 2019年11月17日 上午8:42:41
*/
public class BatchDeleter {
private static Logger log = Logger.getLogger(BatchDeleter.class);
// Commit size
private static final int commitSize=10000;
private String[] tablenames= { "TestTB01",
"TestTB02",
"TestTB03",
"TestTB04",
"TestTB05",
"TestTB06",
"TestTB07",
"TestTB08",
"TestTB09",
"TestTB10",
"TestTB11",
"TestTB12",
"TestTB13",
"TestTB14",
"TestTB15",
"TestTB16",
};
/**
* 批量插入
*/
public void batchDelete(String expiredDate) {
Connection conn = null;
Statement stmt = null;
try{
Class.forName(DBParam.Driver).newInstance();
conn = DriverManager.getConnection(DBParam.DbUrl, DBParam.User, DBParam.Pswd);
stmt = conn.createStatement();
System.out.println("Begin to access "+DBParam.DbUrl+" as "+DBParam.User+"...");
int index=1;
for(String table:tablenames) {
int total=delete(index,table,expiredDate,conn,stmt);
log.info("#"+index+" "+total+" records deleted from table:'"+table+"'.");
index++;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
stmt.close();
conn.close();
} catch (SQLException e) {
log.error("Can't close stmt/conn because of " + e.getMessage());
}
}
}
/**
* change seconds to DayHourMinuteSecond format
* @param stratMs
* @param endMs
* @return
*/
private static String sec2DHMS(long stratMs,long endMs) {
String retval = null;
long secondCount=(endMs-stratMs)/1000;
long days = secondCount / (60 * 60 * 24);
long hours = (secondCount % (60 * 60 * 24)) / (60 * 60);
long minutes = (secondCount % (60 * 60)) / 60;
long seconds = secondCount % 60;
if (days > 0) {
retval = days + "d" + hours + "h" + minutes + "m" + seconds + "s";
} else if (hours > 0) {
retval = hours + "h" + minutes + "m" + seconds + "s";
} else if (minutes > 0) {
retval = minutes + "m" + seconds + "s";
} else {
retval = seconds + "s";
}
return retval;
}
/**
* 按日期删一张表的记录
* @param tableIndex
* @param table
* @param expiredDate
* @param conn
* @param stmt
* @throws SQLException
*/
private int delete(int tableIndex,String table,String expiredDate,Connection conn,Statement stmt) throws SQLException {
int totalDeleted=0;
int expiredCount=0;
do {
String sql="delete from "+table+" WHERE CREATEDTIME < to_date('"+expiredDate+"','yyyy-MM-dd') and rownum<'"+commitSize+"' ";
int deleted=stmt.executeUpdate(sql);
//log.info("#"+tableIndex+" "+deleted+" records deleted from table:'"+table+"'.");
totalDeleted+=deleted;
expiredCount=queryExpiredCount(table,expiredDate,stmt);
}while(expiredCount>0);
return totalDeleted;
}
/**
* 查询过期记录数量
* @param table
* @param expiredDate
* @param conn
* @param stmt
* @return
* @throws SQLException
*/
private int queryExpiredCount(String table,String expiredDate,Statement stmt) throws SQLException {
String sql="SELECT COUNT (*) as cnt FROM "+table+" WHERE CREATEDTIME < to_date('"+expiredDate+"','yyyy-MM-dd') and rownum<10 ";
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
int count = rs.getInt("cnt");
return count;
}
return 0;
}
public static void main(String[] args) {
long startTime = System.currentTimeMillis();
BatchDeleter bd=new BatchDeleter();
bd.batchDelete("2019-07-17");
long endTime = System.currentTimeMillis();
log.info("Time elapsed:" + sec2DHMS(startTime,endTime) );
}
}
输出：
Begin to access jdbc:oracle:thin:@127.0.0.1:1521:orcl as ufo... 2019-11-17 09:40:44,951 INFO[main]-#1 83077 records deleted from table:'TestTB01'. 2019-11-17 09:40:46,165 INFO[main]-#2 83077 records deleted from table:'TestTB02'. 2019-11-17 09:40:49,874 INFO[main]-#3 83077 records deleted from table:'TestTB03'. 2019-11-17 09:40:53,271 INFO[main]-#4 83077 records deleted from table:'TestTB04'. 2019-11-17 09:40:56,728 INFO[main]-#5 83077 records deleted from table:'TestTB05'. 2019-11-17 09:40:59,420 INFO[main]-#6 83077 records deleted from table:'TestTB06'. 2019-11-17 09:41:02,766 INFO[main]-#7 83077 records deleted from table:'TestTB07'. 2019-11-17 09:41:05,983 INFO[main]-#8 83077 records deleted from table:'TestTB08'. 2019-11-17 09:41:08,704 INFO[main]-#9 83077 records deleted from table:'TestTB09'. 2019-11-17 09:41:11,827 INFO[main]-#10 83077 records deleted from table:'TestTB10'. 2019-11-17 09:41:14,895 INFO[main]-#11 83077 records deleted from table:'TestTB11'. 2019-11-17 09:41:18,155 INFO[main]-#12 83077 records deleted from table:'TestTB12'. 2019-11-17 09:41:20,941 INFO[main]-#13 83077 records deleted from table:'TestTB13'. 2019-11-17 09:41:23,992 INFO[main]-#14 83077 records deleted from table:'TestTB14'. 2019-11-17 09:41:25,462 INFO[main]-#15 83077 records deleted from table:'TestTB15'. 2019-11-17 09:41:28,066 INFO[main]-#16 83077 records deleted from table:'TestTB16'. 2019-11-17 09:41:28,068 INFO[main]-Time elapsed:45s
多线程批量删除管理者类：
package com.hy.delete.multithread;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;
import org.apache.log4j.Logger;
/**
* 批量删表管理者
* @author 逆火
*
* 2019年11月17日 上午9:54:46
*/
public class DeleteManager {
private static Logger log = Logger.getLogger(DeleteManager.class);
private String[] tablenames= { "TestTB01",
"TestTB02",
"TestTB03",
"TestTB04",
"TestTB05",
"TestTB06",
"TestTB07",
"TestTB08",
"TestTB09",
"TestTB10",
"TestTB11",
"TestTB12",
"TestTB13",
"TestTB14",
"TestTB15",
"TestTB16",
};
private long startTime;// Start time
private List<DeleteJobInfo> jobInfos;// delete table informations
/**
* 批量插入
*/
public void batchDelete(String expiredDate) {
startTime=System.currentTimeMillis();
jobInfos=new ArrayList<DeleteJobInfo>();
int index=1;
for(String table:tablenames) {
DeleteThread dt=new DeleteThread(index,table,expiredDate,this);
dt.start();
index++;
}
}
/**
* Thread report manager "job done."
* @param tbSN
* @param tableName
* @param timeElasped
*/
public void reportFinished(String tbSN,String tableName,String timeElasped,String deleted) {
jobInfos.add(new DeleteJobInfo(tbSN,tableName,timeElasped,deleted));
if(jobInfos.size()==tablenames.length) {
long endTime = System.currentTimeMillis();
log.info(">>> Delete jobs finished.( time elapsed： " + sec2DHMS(startTime,endTime)+") <<<");
log.info("------------ Details ------------");
log.info("#,table,deleted,time elapsed");
for(DeleteJobInfo jobInfo:jobInfos) {
String raw="{0},{1},{2}";
Object[] arr={jobInfo.tbSn,jobInfo.tableName,jobInfo.deleted,jobInfo.timeElapsed};
String line=MessageFormat.format(raw, arr);
log.info(line);
}
log.info("------------ Details ------------");
}else {
log.info(jobInfos.size()+" deleters completed their jobs.");
}
}
/**
* 成员内部类，用来做数据结构
* 参考：https://blog.****.net/weixin_42762133/article/details/82890555
* @author 逆火
*
* 2019年11月17日 上午9:22:04
*/
protected static final class DeleteJobInfo{
String tbSn;// 表序号
String tableName;// 表名
String timeElapsed;// 耗时
String deleted;// count of deleted records
public DeleteJobInfo(String tbSn,String tableName,String timeElapsed,String deleted) {
this.tbSn=tbSn;
this.tableName=tableName;
this.timeElapsed=timeElapsed;
this.deleted=deleted;
}
}
/**
* change seconds to DayHourMinuteSecond format
* @param stratMs
* @param endMs
* @return
*/
private static String sec2DHMS(long stratMs,long endMs) {
String retval = null;
long secondCount=(endMs-stratMs)/1000;
long days = secondCount / (60 * 60 * 24);
long hours = (secondCount % (60 * 60 * 24)) / (60 * 60);
long minutes = (secondCount % (60 * 60)) / 60;
long seconds = secondCount % 60;
if (days > 0) {
retval = days + "d" + hours + "h" + minutes + "m" + seconds + "s";
} else if (hours > 0) {
retval = hours + "h" + minutes + "m" + seconds + "s";
} else if (minutes > 0) {
retval = minutes + "m" + seconds + "s";
} else {
retval = seconds + "s";
}
return retval;
}
public static void main(String[] args) {
DeleteManager dm=new DeleteManager();
dm.batchDelete("2019-07-17");
}
}
多线程删除删除者类：
package com.hy.delete.multithread;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import org.apache.log4j.Logger;
import com.hy.DBParam;
public class DeleteThread extends Thread {
private static Logger log = Logger.getLogger(DeleteThread.class);
// Commit size
private static final int commitSize=10000;
private int tableIndex;// table serial number
private String table;// table will be deleted
private String expiredDate;// expired date
private DeleteManager menager; // reference to manager
public DeleteThread(int tableIndex,String table,String expiredDate,DeleteManager menager) {
this.tableIndex=tableIndex;
this.table=table;
this.expiredDate=expiredDate;
this.menager=menager;
}
public void run() {
Connection conn = null;
Statement stmt = null;
try{
long startTime = System.currentTimeMillis();
Class.forName(DBParam.Driver).newInstance();
conn = DriverManager.getConnection(DBParam.DbUrl, DBParam.User, DBParam.Pswd);
stmt = conn.createStatement();
log.info("Begin to access "+DBParam.DbUrl+" as "+DBParam.User+"...");
int total=delete(tableIndex,table,expiredDate,conn,stmt);
log.info("#"+tableIndex+" "+total+" records deleted from table:'"+table+"'.");
long endTime = System.currentTimeMillis();
String timeElasped=sec2DHMS(startTime,endTime);
menager.reportFinished(String.valueOf(tableIndex), table, timeElasped,String.valueOf(total));
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
stmt.close();
conn.close();
} catch (SQLException e) {
log.error("Can't close stmt/conn because of " + e.getMessage());
}
}
}
/**
* 按日期删一张表的记录
* @param tableIndex
* @param table
* @param expiredDate
* @param conn
* @param stmt
* @throws SQLException
*/
private int delete(int tableIndex,String table,String expiredDate,Connection conn,Statement stmt) throws SQLException {
int totalDeleted=0;
int expiredCount=0;
do {
String sql="delete from "+table+" WHERE CREATEDTIME < to_date('"+expiredDate+"','yyyy-MM-dd') and rownum<'"+commitSize+"' ";
int deleted=stmt.executeUpdate(sql);
//log.info("#"+tableIndex+" "+deleted+" records deleted from table:'"+table+"'.");
totalDeleted+=deleted;
expiredCount=queryExpiredCount(table,expiredDate,stmt);
}while(expiredCount>0);
return totalDeleted;
}
/**
* 查询过期记录数量
* @param table
* @param expiredDate
* @param conn
* @param stmt
* @return
* @throws SQLException
*/
private int queryExpiredCount(String table,String expiredDate,Statement stmt) throws SQLException {
String sql="SELECT COUNT (*) as cnt FROM "+table+" WHERE CREATEDTIME < to_date('"+expiredDate+"','yyyy-MM-dd') and rownum<10 ";
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
int count = rs.getInt("cnt");
return count;
}
return 0;
}
/**
* change seconds to DayHourMinuteSecond format
* @param stratMs
* @param endMs
* @return
*/
private static String sec2DHMS(long stratMs,long endMs) {
String retval = null;
long secondCount=(endMs-stratMs)/1000;
long days = secondCount / (60 * 60 * 24);
long hours = (secondCount % (60 * 60 * 24)) / (60 * 60);
long minutes = (secondCount % (60 * 60)) / 60;
long seconds = secondCount % 60;
if (days > 0) {
retval = days + "d" + hours + "h" + minutes + "m" + seconds + "s";
} else if (hours > 0) {
retval = hours + "h" + minutes + "m" + seconds + "s";
} else if (minutes > 0) {
retval = minutes + "m" + seconds + "s";
} else {
retval = seconds + "s";
}
return retval;
}
}
这个例子也证明了多线程相对于单线程的优势。
--END-- 2019年11月17日11:24:17