↵起因是这样的，用户要下载对账单明细，也就是交易明细，我们公司的数据库的设计是，一天一张表，类似于trace_20190708,trace_20190709 ....... 这样的类型，所以设计生产者的时候是，一个线程负责某天的表，线程数不要超过查询的天数总和（例如读取20190720-20190730 这十天的数据，那么线程数不能超过10个，也不能过多，看自己系统内存情况），否则，会有线程被一直阻塞。
注 ：其实也可以多线程，读同一张表，这里提供下思路，一般是分页读取，我们可以a线程读取（select * from user limit 0,10 下面就直接用limit x，y代表了）limit 2n,100 ,B线程读取limit 2n+1,100 这样写设计sql读取，这样设计的目的是，不用写锁，若是多个线程用同一个 limit n，100，这样设计，那么会用并发现象，那么就要加锁，比如我在读limit 10,20 ，那么你要读limt30,20 你要等我读完，但是我多线程就是为了读取速度快，并发执行，加锁等待了，多线程的意义何在，所以在sql 上做些文章就好。
测试类
package com.example.demo.test;
/**
* @Author: myc
* @Description:
* @Date 下午 4:51 2019/6/26 0026
*/
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* 测试POI
*
* @author alex
*/
public class PoiTest {
public static void main(String[] args) {
/**
* 使用线程池进行线程管理。
*/
ExecutorService es = Executors.newFixedThreadPool(20);
/**
* 使用计数栅栏
*/
CountDownLatch doneSignal = new CountDownLatch(1);
String xlsFile = "d:/xlsx/poiSXXFSBigData" + "2019010" + ".xlsx";
PoiExcel.multiThreadWrite(es, doneSignal, xlsFile);
es.shutdown();
}
}读写excel ,这里采用了生产者-消费者模式，将读数据库的数据，与写入excel，两个步骤分离，采用了blockqueue。考虑到一个excel的工作簿数据的容量大概是100W行，所以将其分多个工作簿，处理，这样就可以读写更多数据。但是有个问题是，多线程下，读写的并发问题，在多个消费者的情况下，会有些问题，所以建议开一个消费者就好。
sheet.setRandomAccessWindowSize(windowSize);注意这个设置，这个设置是将数据读到内存中windowSize个，超过这个数后就写入到磁盘零时文件中。若是设置为 -1，那么数据会全部读取到内存中，这样数据过多内存会被撑爆package com.example.demo.test;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.util.SheetUtil;
import org.apache.poi.xssf.streaming.SXSSFSheet;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import java.io.FileOutputStream;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;
/**
* @Author: myc
* @Description: 用Poi读写大量数据
* @Date 下午 2:12 2019/6/28 0028
*/
public class PoiExcel {
private static SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
protected static volatile SXSSFWorkbook wb = new SXSSFWorkbook(100);
/**
* 总行号
*/
protected static AtomicInteger rowNo = new AtomicInteger(0);
/**
* 页行号
*/
protected static AtomicInteger pageRowNo = new AtomicInteger(0);
protected static AtomicInteger count = new AtomicInteger(0);
public static BlockingQueue<List<PoiEntity>> queue = new ArrayBlockingQueue(5);
public static BlockingQueue<String> sqlQueue = new LinkedBlockingQueue();
/**
* excel 每个sheet大小
*/
protected static final int MAX_SHEET_PAGE_SIZE = 200000;
/**
* 查询总记录数
*/
protected static int TOTAL_COUNT;
/**
* 判断CountDownLatch，当所有线程运行结束，就写入到文件流中
*/
protected static AtomicInteger DONESIGNAL_COUNT;
/**
* 表名数组
*/
protected static List<String> tableNameArr = new ArrayList<>();
/**
* 读取数据库中存储的数据行数
*/
public static int PAGE_SIZE = 50000;
/**
* 工作表对象
*/
protected static volatile SXSSFSheet sheet;
/**
* excel工作簿数组
*/
protected static ArrayList<SXSSFSheet> sheetList = new ArrayList<>();
/**
* cell列数
*/
private static final int cellLength = 10;
private static final int windowSize = 200;
public void customerData(CountDownLatch doneSignal) throws Exception {
List list = queue.take();
int len = list.size();
for (int i = 0; i < len; i++) {
Row row_value = null;
synchronized (rowNo) {
if (rowNo.get() % MAX_SHEET_PAGE_SIZE == 0) {
if (count.get() < sheetList.size()) {
sheet = sheetList.get(count.get());
pageRowNo.set(0); //每当新建了工作表就将当前工作表的行号重置为0
createHeader();
setColumnWidthByType(sheet, cellLength);
count.incrementAndGet();
}
}
row_value = sheet.createRow(pageRowNo.incrementAndGet());
rowNo.incrementAndGet();
}
addToRow(i, row_value, list);
}
System.out.println("sheet name " + sheet.getSheetName() + " rowNo " + rowNo + " DONESIGNAL_COUNT " + DONESIGNAL_COUNT);
DONESIGNAL_COUNT.getAndAdd(-list.size());
list.clear();
if (DONESIGNAL_COUNT.get() == 0) {
doneSignal.countDown();
}
}
protected void addToRow(int i, Row row_value, List _list) {
List<PoiEntity> list = _list;
Cell cel0_value = row_value.createCell(0);
cel0_value.setCellValue(list.get(i).getTraceNo());
Cell cel2_value = row_value.createCell(1);
cel2_value.setCellValue(list.get(i).getMerchantNum());
Cell cel3_value = row_value.createCell(2);
cel3_value.setCellValue(list.get(i).getTotalFee() + "");
Cell cel4_value = row_value.createCell(3);
cel4_value.setCellValue(list.get(i).getMerchantName());
Cell cel5_value = row_value.createCell(4);
cel5_value.setCellValue(list.get(i).getDynamicType());
Cell cel6_value = row_value.createCell(5);
cel6_value.setCellValue(list.get(i).getTransBegin());
Cell cel7_value = row_value.createCell(6);
cel7_value.setCellValue(list.get(i).getTransStatus());
Cell cel8_value = row_value.createCell(7);
cel8_value.setCellValue(list.get(i).getRefundFee() + "");
Cell cel9_value = row_value.createCell(8);
cel9_value.setCellValue(list.get(i).getOutTransNo());
Cell cel10_value = row_value.createCell(9);
cel10_value.setCellValue(list.get(i).getRateFee());
//Cell cel11_value = row_value.createCell(10);
// cel11_value.setCellValue(list.get(i).getBankType());
/* Cell cel12_value = row_value.createCell(11);
cel2_value.setCellValue(list.get(i).getTerminalNum());*/
}
/**
* 定义表头
*/
protected void createHeader() {
Row row = sheet.createRow(0);
Cell cel0 = row.createCell(0);
cel0.setCellValue("traceNo");
Cell cel2 = row.createCell(1);
cel2.setCellValue("merchantNum");
Cell cel3 = row.createCell(2);
cel3.setCellValue("totalFee");
Cell cel4 = row.createCell(3);
cel4.setCellValue("merchantName");
Cell cel5 = row.createCell(4);
cel5.setCellValue("dynamicType");
Cell cel6 = row.createCell(5);
cel6.setCellValue(" transBegin ");
Cell cel7 = row.createCell(6);
cel7.setCellValue("transStatus");
Cell cel8 = row.createCell(7);
cel8.setCellValue("refundFee");
Cell cel9 = row.createCell(8);
cel9.setCellValue("outTransNo");
Cell cel10 = row.createCell(9);
cel10.setCellValue("rateFee");
//Cell cel11 = row.createCell(10);
// cel11.setCellValue("bankType");
/* Cell cel2 = row.createCell(11);
cel2.setCellValue("terminalNum");*/
}
protected static int getListCount(List tableNameArr) throws Exception {
PreparedStatement stmt = DbUtils.getStm();
int listCount = 0;
for (int i = 0; i < tableNameArr.size(); i++) {
String queryCount = "select count(1) from " + tableNameArr.get(i);
ResultSet rsTotal = stmt.executeQuery(queryCount);
rsTotal.next();
listCount += rsTotal.getInt(1);
}
return listCount;
}
/**
* 生成工作簿
*
* @param sheet
*/
protected static void setSheet(SXSSFSheet sheet) {
int size = 1;
if (TOTAL_COUNT > MAX_SHEET_PAGE_SIZE) {
size = TOTAL_COUNT / MAX_SHEET_PAGE_SIZE == 0 ? TOTAL_COUNT / MAX_SHEET_PAGE_SIZE : (TOTAL_COUNT / MAX_SHEET_PAGE_SIZE) + 1;
}
for (int i = 0; i < size; i++) {
/**建立新的sheet对象*/
sheet = wb.createSheet("我的第" + i + "个工作簿");
sheet.setRandomAccessWindowSize(windowSize);
/**动态指定当前的工作表*/
sheet = wb.getSheetAt(i);
sheetList.add(sheet);
}
}
/**
* 根据类型指定excel文件的列宽
*/
private void setColumnWidthByType(SXSSFSheet sheet, int titleLength) {
sheet.trackAllColumnsForAutoSizing();
for (int i = 0; i < titleLength; i++) {
int columnWidth = sheet.getRow(0).getCell(i).getStringCellValue().length();//获取表头的宽度
int autowidth = (int) SheetUtil.getColumnWidth(sheet, i, false, 1, sheet.getLastRowNum());
if (columnWidth > autowidth) {
sheet.setColumnWidth(i, (int) 400.0D * (columnWidth + 1));
} else {
sheet.autoSizeColumn(i);
}
}
}
/**
* 添加表名
*
* @param dateList
*/
private static void addTable(List<String> dateList) {
dateList.forEach(date -> {
/**兴业*/
tableNameArr.add("xingye_bill_download_day_101590267206_" + date);
tableNameArr.add("xingye_bill_download_day_101540080217_" + date);
/**汇付*/
tableNameArr.add("posp_huifu_detail_day_" + date);
});
}
/**
* 添加sql
*
* @param dateList
* @return
*/
private static List<String> getSqlList(List<String> dateList, String where) {
List<String> listSql = new ArrayList<>();
dateList.forEach(date -> {
/**兴业*/
String sql1 = "select id,merchant_num merchantNum,merchant_name merchantName,trans_type dynamicType,trans_time transBegin" +
" ,trans_status transStatus,total_fee totalFee,refund_fee refundFee,third_merchant_num outTransNo," +
" rate_fee rateFee ,trace_num traceNo from xingye_bill_download_day_101590267206_" + date
+ " WHERE id > ownId " + where + " ORDER BY id ASC LIMIT " + PAGE_SIZE;
String sql2 = "select id,merchant_num merchantNum,merchant_name merchantName,trans_type dynamicType,trans_time transBegin" +
" ,trans_status transStatus,total_fee totalFee,refund_fee refundFee,third_merchant_num outTransNo," +
" rate_fee rateFee ,trace_num traceNo from xingye_bill_download_day_101540080217_" + date
+ " WHERE id > ownId " + where + " ORDER BY id ASC LIMIT " + PAGE_SIZE;
/**汇付*/
String sql3 = "select id,merchant_num merchantNum,merchant_name merchantName ,trade_type dynamicType,DATE_FORMAT(trade_date,'%Y-%m-%d-%H-%i-%s') transBegin " +
" ,trade_status transStatus,total_fee totalFee,recorded_money refundFee,outside_order_num outTransNo, " +
" rate_fee rateFee ,trace_num traceNo from posp_huifu_detail_day_" + date
+ " WHERE id > ownId " + where + " ORDER BY id ASC LIMIT " + PAGE_SIZE;
listSql.add(sql1);
listSql.add(sql2);
listSql.add(sql3);
});
return listSql;
}
/**
* 得到两个日期之间的天数，数组
*
* @param dBegin
* @param dEnd
* @return
*/
public static List<String> findDates(Date dBegin, Date dEnd) {
List lDate = new ArrayList();
lDate.add(sdf.format(dBegin));
Calendar calBegin = Calendar.getInstance();
// 使用给定的 Date 设置此 Calendar 的时间
calBegin.setTime(dBegin);
Calendar calEnd = Calendar.getInstance();
// 使用给定的 Date 设置此 Calendar 的时间
calEnd.setTime(dEnd);
// 测试此日期是否在指定日期之后
while (dEnd.after(calBegin.getTime())) {
// 根据日历的规则，为给定的日历字段添加或减去指定的时间量
calBegin.add(Calendar.DAY_OF_MONTH, 1);
lDate.add(sdf.format(calBegin.getTime()));
}
return lDate;
}
/**
* 使用多线程进行Excel写操作，提高写入效率。
*/
public static void multiThreadWrite(ExecutorService es, CountDownLatch doneSignal, String xlsFile) {
try {
/**预生产数据*/
long startTime = System.currentTimeMillis(); //开始时间
Date begin = sdf.parse("20190602");
Date end = sdf.parse("20190602");
List<String> dateList = findDates(begin, end);
addTable(dateList);
TOTAL_COUNT = getListCount(tableNameArr);
DONESIGNAL_COUNT = new AtomicInteger(TOTAL_COUNT);
setSheet(sheet);
sheet = sheetList.get(0);
String where = "";
getSqlList(dateList, where).forEach(sql -> {
try {
sqlQueue.put(sql);
} catch (InterruptedException e) {
e.printStackTrace();
}
});
/**多线程处理数据*/
int size = sqlQueue.size();
/**最多创建10个线程，确保线程不在开始时就被阻塞*/
if (size > 0) {
size = size > 12 ? 10 : size;
for (int i = 0; i < size; i++) {
es.submit(new PoiProductor(doneSignal));
}
}
PoiExcel poiExcel = new PoiExcel();
es.submit(new PoiWriter(doneSignal, poiExcel));
doneSignal.await();
System.out.println("read finish execute time: " + (System.currentTimeMillis() - startTime) / 1000 + " s");
FileOutputStream os = new FileOutputStream(xlsFile);
wb.write(os);
os.flush();
os.close();
System.out.println(" outPutStream finish execute time: " + (System.currentTimeMillis() - startTime) / 1000 + " s");
} catch (Exception e) {
e.printStackTrace();
}
}
}从数据库读数 生产者 ↵
package com.example.demo.test;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
/**
* @Author: myc
* @Description: 获取对账单表中的数据并放在queue中 ,这里每个线程对应一张表,读完可读剩余的某一张表,保证原子性。
* 新建的线程个数，不要超过sqlQueue的大小，否则会有线程阻塞消耗内存。
* @Date 下午 5:37 2019/6/28 0028
*/
public class PoiProductor implements Runnable {
private final CountDownLatch doneSignal;
public PoiProductor(CountDownLatch doneSignal) {
this.doneSignal = doneSignal;
}
@Override
public void run() {
List list = null;
String sql = null;
int id = 0;
while (true) {
try {
//synchronized (doneSignal) {
if (null == list || list.size() < 1) {
id = 0;
if (PoiExcel.sqlQueue.size() > 0) {
sql = PoiExcel.sqlQueue.take();
} else {
break;
}
}
//}
if (null != list && list.size() > 0) {
id = getId(list);
}
list = getListData(sql, id);
PoiExcel.queue.put(list);
} catch (Exception e) {
e.printStackTrace();
}
}
}
public static int getId(List list) throws Exception {
List<PoiEntity> _list = list;
int id = _list.get(_list.size() - 1).getId();
return id;
}
private static void addToList(List _list, ResultSet rs) throws SQLException, ParseException {
List<PoiEntity> list = _list;
while (rs.next()) {
String dynamicType = getDynamicType(rs);
String transStatus = getTransStatus(rs);
PoiEntity usera = new PoiEntity();
usera.setId((rs.getInt("id")));
usera.setTraceNo((rs.getString("traceNo")));
usera.setMerchantNum((rs.getString("merchantNum")));
usera.setTotalFee(rs.getBigDecimal("totalFee"));
usera.setMerchantName(rs.getString("merchantName"));
// usera.setTerminalNum(rs.getString("terminalNum"));
usera.setDynamicType(dynamicType);
usera.setTransBegin(rs.getString("transBegin"));
usera.setTransStatus(transStatus);
usera.setRefundFee(rs.getBigDecimal("refundFee"));
usera.setOutTransNo(rs.getString("outTransNo"));
// usera.setBankType(rs.getString("bankType"));
usera.setRateFee(rs.getString("rateFee"));
list.add(usera);
}
}
private static String getTransStatus(ResultSet rs) throws SQLException {
String transStatus = rs.getString("transStatus");
/* if (transStatus.contains("weixin")) {
transStatus = "微信";
}*/
return transStatus;
}
private static String getDynamicType(ResultSet rs) throws SQLException {
String dynamicType = rs.getString("dynamicType");
/* if (dynamicType.contains("weixin")) {
dynamicType = "微信支付";
}
if (dynamicType.contains("alipay")) {
dynamicType = "支付宝支付";
}*/
return dynamicType;
}
public static List getListData(String sql, int id) throws Exception {
List _list = new ArrayList();
PreparedStatement stmt = DbUtils.getStm();
//posp_merchant_account_stats_detail_day_20190607
sql = sql.replace("ownId", id + "");
ResultSet rs = stmt.executeQuery(sql);
if (null != rs) {
addToList(_list, rs);
return _list;
} else {
_list.clear();
return null;
}
}
}将数据写入到excel --消费者
package com.example.demo.test;
import java.util.concurrent.CountDownLatch;
/**
* @Author: myc 进行sheet写操作
* @Description:
* @Date 上午 9:58 2019/6/28 0028
*/
public class PoiWriter implements Runnable {
private final CountDownLatch doneSignal;
private PoiExcel poiExcel;
public PoiWriter(CountDownLatch doneSignal,PoiExcel poiExcel) {
this.doneSignal = doneSignal;
this.poiExcel = poiExcel;
}
@Override
public void run() {
try {
while (true) {
if(doneSignal.getCount() <= 0){
break;
}
poiExcel.customerData(doneSignal);
}
} catch (Exception e) {
e.printStackTrace();
} /*finally {
doneSignal.countDown();
System.out.println(" Count: " + doneSignal.getCount() + " thread name " + Thread.currentThread().getName());
}*/
}
}实体类
package com.example.demo.test;
import java.math.BigDecimal;
/**
* @Author: myc
* @Description:
* @Date 上午 9:31 2019/7/1 0001
*/
public class PoiEntity {
private Integer id;
private String merchantNum;
private String merchantName;
private String terminalNum;
private String dynamicType;
private String transBegin;
private String transStatus;
private BigDecimal totalFee;
private BigDecimal refundFee;
private String outTransNo;
private String bankType;
private String rateFee;
private String traceNo;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getMerchantNum() {
return merchantNum;
}
public void setMerchantNum(String merchantNum) {
this.merchantNum = merchantNum;
}
public String getMerchantName() {
return merchantName;
}
public void setMerchantName(String merchantName) {
this.merchantName = merchantName;
}
public String getTerminalNum() {
return terminalNum;
}
public void setTerminalNum(String terminalNum) {
this.terminalNum = terminalNum;
}
public String getDynamicType() {
return dynamicType;
}
public void setDynamicType(String dynamicType) {
this.dynamicType = dynamicType;
}
public String getTransBegin() {
return transBegin;
}
public void setTransBegin(String transBegin) {
this.transBegin = transBegin;
}
public String getTransStatus() {
return transStatus;
}
public void setTransStatus(String transStatus) {
this.transStatus = transStatus;
}
public BigDecimal getTotalFee() {
return totalFee;
}
public void setTotalFee(BigDecimal totalFee) {
this.totalFee = totalFee;
}
public BigDecimal getRefundFee() {
return refundFee;
}
public void setRefundFee(BigDecimal refundFee) {
this.refundFee = refundFee;
}
public String getOutTransNo() {
return outTransNo;
}
public void setOutTransNo(String outTransNo) {
this.outTransNo = outTransNo;
}
public String getBankType() {
return bankType;
}
public void setBankType(String bankType) {
this.bankType = bankType;
}
public String getRateFee() {
return rateFee;
}
public void setRateFee(String rateFee) {
this.rateFee = rateFee;
}
public String getTraceNo() {
return traceNo;
}
public void setTraceNo(String traceNo) {
this.traceNo = traceNo;
}
}db
package com.example.demo.test;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
/**
* @Author: myc
* @Description:
* @Date 下午 5:43 2019/6/28 0028
*/
public class DbUtils {
static String url = "jdbc:mysql://localhost:3306/posp?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull";
static String user = "root";
static String password = "root";
public static PreparedStatement getStm() throws Exception {
Class.forName("com.mysql.jdbc.Driver").newInstance();
//获取数据库连接
Connection conn = null;
PreparedStatement stmt = null;
conn = DriverManager.getConnection(url, user, password);
stmt = conn.prepareStatement("");
return stmt;
}
}
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