本文实例为大家分享了Java实现excel大数据量导入的具体代码，供大家参考，具体内容如下
情景分析：
通常我们通过poi读取excel文件时，若在用户模式下，由于数据量较大、Sheet较多，很容易出现内存溢出的情况
用户模式读取excel的典型代码如下：
FileInputStream file = new FileInputStream("c:\\test.xlsx");
Workbook wb=new XSSFWorkbook(file);
而03版（xls）excel文件每个sheet最大长度为 65536行，07版（xlsx）excel文件每个sheet最大长度为 1048576行，因此我们主要解决07版（xlsx）excel大数据量导入出现内存溢出的问题
由于读取cvs文件效率高且占用内存少，所以我们采用xlsx转换为cvs的方式来解决
读取xlsx格式数据：
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.openxml4j.exceptions.OpenXML4JException;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.openxml4j.opc.PackageAccess;
import org.apache.poi.ss.usermodel.BuiltinFormats;
import org.apache.poi.ss.usermodel.DataFormatter;
import org.apache.poi.xssf.eventusermodel.ReadOnlySharedStringsTable;
import org.apache.poi.xssf.eventusermodel.XSSFReader;
import org.apache.poi.xssf.model.StylesTable;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
public class XLSX2CSV {
enum xssfDataType {
BOOL, ERROR, FORMULA, INLINESTR, SSTINDEX, NUMBER,
}
/**
* 使用xssf_sax_API处理Excel,请参考： http://poi.apache.org/spreadsheet/how-to.html#xssf_sax_api
*/
class MyXSSFSheetHandler extends DefaultHandler {
private StylesTable stylesTable;
private ReadOnlySharedStringsTable sharedStringsTable;
private final PrintStream output;
private final int minColumnCount;
private boolean vIsOpen;
private xssfDataType nextDataType;
private short formatIndex;
private String formatString;
private final DataFormatter formatter;
private int thisColumn = -1;
private int lastColumnNumber = -1;
private StringBuffer value;
private String[] record;
private List<String[]> rows = new ArrayList<String[]>();
private boolean isCellNull = false;
public MyXSSFSheetHandler(StylesTable styles,ReadOnlySharedStringsTable strings, int cols, PrintStream target) {
this.stylesTable = styles;
this.sharedStringsTable = strings;
this.minColumnCount = cols;
this.output = target;
this.value = new StringBuffer();
this.nextDataType = xssfDataType.NUMBER;
this.formatter = new DataFormatter();
record = new String[this.minColumnCount];
rows.clear();// 每次读取都清空行集合
}
public void startElement(String uri, String localName, String name,Attributes attributes) throws SAXException {
if ("inlineStr".equals(name) || "v".equals(name)) {
vIsOpen = true;
// Clear contents cache
value.setLength(0);
}
// c => cell
else if ("c".equals(name)) {
// Get the cell reference
String r = attributes.getValue("r");
int firstDigit = -1;
for (int c = 0; c < r.length(); ++c) {
if (Character.isDigit(r.charAt(c))) {
firstDigit = c;
break;
}
}
thisColumn = nameToColumn(r.substring(0, firstDigit));
// Set up defaults.
this.nextDataType = xssfDataType.NUMBER;
this.formatIndex = -1;
this.formatString = null;
String cellType = attributes.getValue("t");
String cellStyleStr = attributes.getValue("s");
if ("b".equals(cellType))
nextDataType = xssfDataType.BOOL;
else if ("e".equals(cellType))
nextDataType = xssfDataType.ERROR;
else if ("inlineStr".equals(cellType))
nextDataType = xssfDataType.INLINESTR;
else if ("s".equals(cellType))
nextDataType = xssfDataType.SSTINDEX;
else if ("str".equals(cellType))
nextDataType = xssfDataType.FORMULA;
else if (cellStyleStr != null) {
// It's a number, but almost certainly one
// with a special style or format
int styleIndex = Integer.parseInt(cellStyleStr);
XSSFCellStyle style = stylesTable.getStyleAt(styleIndex);
this.formatIndex = style.getDataFormat();
this.formatString = style.getDataFormatString();
if (this.formatString == null)
this.formatString = BuiltinFormats
.getBuiltinFormat(this.formatIndex);
}
}
}
public void endElement(String uri, String localName, String name)throws SAXException {
String thisStr = null;
// v => contents of a cell
if ("v".equals(name)) {
// Process the value contents as required.
// Do now, as characters() may be called more than once
switch (nextDataType) {
case BOOL:
char first = value.charAt(0);
thisStr = first == '0' ? "FALSE" : "TRUE";
break;
case ERROR:
thisStr = "\"ERROR:" + value.toString() + '"';
break;
case FORMULA:
// A formula could result in a string value,
// so always add double-quote characters.
thisStr = '"' + value.toString() + '"';
break;
case INLINESTR:
// TODO: have seen an example of this, so it's untested.
XSSFRichTextString rtsi = new XSSFRichTextString(value.toString());
thisStr = '"' + rtsi.toString() + '"';
break;
case SSTINDEX:
String sstIndex = value.toString();
try {
int idx = Integer.parseInt(sstIndex);
XSSFRichTextString rtss = new XSSFRichTextString(sharedStringsTable.getEntryAt(idx));
thisStr = rtss.toString();
} catch (NumberFormatException ex) {
output.println("Failed to parse SST index '" + sstIndex
+ "': " + ex.toString());
}
break;
case NUMBER:
String n = value.toString();
// 判断是否是日期格式
if (HSSFDateUtil.isADateFormat(this.formatIndex, n)) {
Double d = Double.parseDouble(n);
Date date=HSSFDateUtil.getJavaDate(d);
thisStr=formateDateToString(date);
} else if (this.formatString != null)
thisStr = formatter.formatRawCellContents(
Double.parseDouble(n), this.formatIndex,
this.formatString);
else
thisStr = n;
break;
default:
thisStr = "(TODO: Unexpected type: " + nextDataType + ")";
break;
}
// Output after we've seen the string contents
// Emit commas for any fields that were missing on this row
if (lastColumnNumber == -1) {
lastColumnNumber = 0;
}
//判断单元格的值是否为空
if (thisStr == null || "".equals(isCellNull)) {
isCellNull = true;// 设置单元格是否为空值
}
record[thisColumn] = thisStr;
// Update column
if (thisColumn > -1)
lastColumnNumber = thisColumn;
} else if ("row".equals(name)) {
// Print out any missing commas if needed
if (minColumns > 0) {
// Columns are 0 based
if (lastColumnNumber == -1) {
lastColumnNumber = 0;
}
if (isCellNull == false && record[0] != null
&& record[1] != null)// 判断是否空行
{
rows.add(record.clone());
isCellNull = false;
for (int i = 0; i < record.length; i++) {
record[i] = null;
}
}
}
lastColumnNumber = -1;
}
}
public List<String[]> getRows() {
return rows;
}
public void setRows(List<String[]> rows) {
this.rows = rows;
}
/**
* Captures characters only if a suitable element is open. Originally
* was just "v"; extended for inlineStr also.
*/
public void characters(char[] ch, int start, int length)throws SAXException {
if (vIsOpen)
value.append(ch, start, length);
}
/**
* Converts an Excel column name like "C" to a zero-based index.
* @param name
* @return Index corresponding to the specified name
*/
private int nameToColumn(String name) {
int column = -1;
for (int i = 0; i < name.length(); ++i) {
int c = name.charAt(i);
column = (column + 1) * 26 + c - 'A';
}
return column;
}
private String formateDateToString(Date date) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//格式化日期
return sdf.format(date);
}
}
private OPCPackage xlsxPackage;
private int minColumns;
private PrintStream output;
/**
* Creates a new XLSX -> CSV converter
*
* @param pkg
* The XLSX package to process
* @param output
* The PrintStream to output the CSV to
* @param minColumns
* The minimum number of columns to output, or -1 for no minimum
*/
public XLSX2CSV(OPCPackage pkg, PrintStream output,int minColumns) {
this.xlsxPackage = pkg;
this.output = output;
this.minColumns = minColumns;
}
/**
* Parses and shows the content of one sheet using the specified styles and
* shared-strings tables.
* @param styles
* @param strings
* @param sheetInputStream
*/
public List<String[]> processSheet(StylesTable styles,
ReadOnlySharedStringsTable strings, InputStream sheetInputStream)
throws IOException, ParserConfigurationException, SAXException {
InputSource sheetSource = new InputSource(sheetInputStream);
SAXParserFactory saxFactory = SAXParserFactory.newInstance();
SAXParser saxParser = saxFactory.newSAXParser();
XMLReader sheetParser = saxParser.getXMLReader();
MyXSSFSheetHandler handler = new MyXSSFSheetHandler(styles, strings,this.minColumns, this.output);
sheetParser.setContentHandler(handler);
sheetParser.parse(sheetSource);
return handler.getRows();
}
/**
* 初始化这个处理程序
* @throws IOException
* @throws OpenXML4JException
* @throws ParserConfigurationException
* @throws SAXException
*/
public List<String[]> process() throws IOException, OpenXML4JException,ParserConfigurationException, SAXException {
ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(this.xlsxPackage);
XSSFReader xssfReader = new XSSFReader(this.xlsxPackage);
List<String[]> list = null;
StylesTable styles = xssfReader.getStylesTable();
XSSFReader.SheetIterator iter = (XSSFReader.SheetIterator) xssfReader.getSheetsData();
int index = 0;
while (iter.hasNext()) {
InputStream stream = iter.next();
index++;
//默认取第一个工作薄
if(index == 1){
list = processSheet(styles, strings, stream);
stream.close();
}
}
return list;
}
/**
* 读取Excel
*
* @param path
* 文件路径
* @param sheetName
* sheet名称
* @param minColumns
* 列总数
* @return
* @throws SAXException
* @throws ParserConfigurationException
* @throws OpenXML4JException
* @throws IOException
*/
private static List<String[]> readerExcel(String path,int minColumns) throws IOException, OpenXML4JException,ParserConfigurationException, SAXException {
OPCPackage p = OPCPackage.open(path, PackageAccess.READ);
XLSX2CSV xlsx2csv = new XLSX2CSV(p, System.out, minColumns);
List<String[]> list = xlsx2csv.process();
p.close();
return list;
}
/**
* 读取Excel
*
* @param file
* File
* @param sheetName
* sheet名称
* @param minColumns
* 列总数
* @return
* @throws SAXException
* @throws ParserConfigurationException
* @throws OpenXML4JException
* @throws IOException
*/
private static List<String[]> readerExcelInputStream(File file,int minColumns) throws IOException, OpenXML4JException, ParserConfigurationException, SAXException {
OPCPackage p = OPCPackage.openOrCreate(file);
XLSX2CSV xlsx2csv = new XLSX2CSV(p, System.out, minColumns);
List<String[]> list = xlsx2csv.process();
p.close();
return list;
}
//获取表头及数据内容,可在业务层调用
public static Map<String,Object> getTableDate(InputStream in) throws IOException, OpenXML4JException, ParserConfigurationException, SAXException{
File out = new File("C:\\date.xlsx");//默认在C盘生成date.xlsx文件
OutputStream output = null;
try {
output = new FileOutputStream(out);
byte[] buf = new byte[1024];
int bytesRead;
while ((bytesRead = in.read(buf)) > 0) {
output.write(buf, 0, bytesRead);
}
} finally {
in.close();
output.close();
}
Map<String,Object> map = new HashMap<String,Object>();
List<String> headresult = new ArrayList<String>();//表头集合
List<List<String>> dataresult = new ArrayList<List<String>>();//表数据集合
List<String[]> list = readerExcelInputStream(out,30);//默认读取30列
for(int i=0;i<list.size();i++){
if(i == 0){
for(String cell : list.get(i)){
if(cell != null){
headresult.add(cell);
}
}
}else{
List<String> dataList = new ArrayList<String>();
for(String cell : list.get(i)){
dataList.add(cell == null ? "" : cell);
}
dataresult.add(dataList);
}
}
map.put("headresult", headresult);
map.put("dataresult", dataresult);
return map;
}
public static void main(String[] args) throws Exception {
File file = new File("C:/Users/Administrator/Desktop/测试.xlsx");
System.out.println("开始读取...");
List<String[]> list = XLSX2CSV.readerExcelInputStream(file, 30);//默认读取30列
System.out.println("数据量："+list.size());
for(int i=0;i<list.size();i++){
if(i > 0){
for (String cell : list.get(i)) {
System.out.print(cell + ",");
}
System.out.println();
}
}
}
}
说明：
代码中的加载excel的核心方法：
OPCPackage pkg = OPCPackage.open(path);//文件路径 OPCPackage pkg = OPCPackage.openOrCreate(file);//文件 OPCPackage pkg = OPCPackage.open(InputStream);//文件流
文件流方式对内存依赖极大，所以实际应用时，如果只能获取文件流的话，可以先将文件通过流拷贝到本地再解析代码中的
若上传文件大小超过限制，可在配置文件中设置，SpringBoot2项目application.properties中设置：
spring.servlet.multipart.maxFileSize=50MB spring.servlet.multipart.maxRequestSize=100MB
实际业务数据入库的话也可采用异步任务@Async的方式来提高入库效率：
import java.util.Map;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
import cn.com.app.dao.JkconfigDao;
@Service
public class JkrzService {
@Autowired
private JkconfigDao jkconfigDao;
@Async("myTaskAsyncPool")
public void transJkrz(Map<String, Object> m) {
jkconfigDao.insert(m);
}
}
线程池配置：
import java.util.concurrent.Executor;
import java.util.concurrent.ThreadPoolExecutor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
@Configuration
@EnableAsync
public class AsyncTaskConfig {
@Autowired
private TaskThreadPoolConfig config;
// ThredPoolTaskExcutor的处理流程
// 当池子大小小于corePoolSize，就新建线程，并处理请求
// 当池子大小等于corePoolSize，把请求放入workQueue中，池子里的空闲线程就去workQueue中取任务并处理
// 当workQueue放不下任务时，就新建线程入池，并处理请求，如果池子大小撑到了maximumPoolSize，就用RejectedExecutionHandler来做拒绝处理
// 当池子的线程数大于corePoolSize时，多余的线程会等待keepAliveTime长时间，如果无请求可处理就自行销毁
// 当threadNamePrefix设置为true，则核心线程也会超时关闭
@Bean
public Executor myTaskAsyncPool() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(config.getCorePoolSize());
executor.setMaxPoolSize(config.getMaxPoolSize());
executor.setQueueCapacity(config.getQueueCapacity());
executor.setKeepAliveSeconds(config.getKeepAliveSeconds());
executor.setAllowCoreThreadTimeOut(true);
executor.setThreadNamePrefix("MyExecutor-");
// rejection-policy：当pool已经达到max size的时候，如何处理新任务
// CALLER_RUNS：不在新线程中执行任务，而是由调用者所在的线程来执行
executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
executor.initialize();
return executor;
}
}
参数配置：
#核心线程数,当线程数小于核心线程数时,即使有线程空闲,线程池也会优先创建新线程,设置allowCoreThreadTimeout=true（默认false）时,核心线程会超时退出 spring.task.pool.corePoolSize=20 #最大线程数,当线程数大于等于corePoolSize,且任务队列已满时,线程池会创建新线程来处理任务 spring.task.pool.maxPoolSize=60 #线程空闲时间,当线程空闲时间达到keepAliveSeconds(秒)时,线程会退出,直到线程数量等于corePoolSize,如果allowCoreThreadTimeout=true,则会直到线程数量等于0 spring.task.pool.keepAliveSeconds=1 #任务队列容量,当核心线程数达到最大时,新任务会放在队列中排队等待执行 spring.task.pool.queueCapacity=400
读取xls格式数据：
import org.apache.poi.hssf.eventusermodel.*;
import org.apache.poi.hssf.eventusermodel.dummyrecord.LastCellOfRowDummyRecord;
import org.apache.poi.hssf.eventusermodel.dummyrecord.MissingCellDummyRecord;
import org.apache.poi.hssf.model.HSSFFormulaParser;
import org.apache.poi.hssf.record.*;
import org.apache.poi.hssf.usermodel.HSSFDataFormatter;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
/**
* @desc 用于解决.xls2003版本大数据量问题
**/
public class ExcelXlsReader implements HSSFListener {
//存储所有数据
private List<List<String>> dataList = new ArrayList<List<String>>();
private int minColums = -1;
private POIFSFileSystem fs;
/**
* 总行数
*/
private int totalRows=0;
/**
* 上一行row的序号
*/
private int lastRowNumber;
/**
* 上一单元格的序号
*/
private int lastColumnNumber;
/**
* 是否输出formula，还是它对应的值
*/
private boolean outputFormulaValues = true;
/**
* 用于转换formulas
*/
private EventWorkbookBuilder.SheetRecordCollectingListener workbookBuildingListener;
//excel2003工作簿
private HSSFWorkbook stubWorkbook;
private SSTRecord sstRecord;
private FormatTrackingHSSFListener formatListener;
private final HSSFDataFormatter formatter = new HSSFDataFormatter();
/**
* 文件的绝对路径
*/
private String filePath = "";
//表索引
private int sheetIndex = 0;
private BoundSheetRecord[] orderedBSRs;
@SuppressWarnings("unchecked")
private ArrayList boundSheetRecords = new ArrayList();
private int nextRow;
private int nextColumn;
private boolean outputNextStringRecord;
//当前行
private int curRow = 0;
//存储一行记录所有单元格的容器
private List<String> cellList = new ArrayList<String>();
/**
* 判断整行是否为空行的标记
*/
private boolean flag = false;
@SuppressWarnings("unused")
private String sheetName;
/**
* 遍历excel下所有的sheet
*
* @param fileName
* @throws Exception
*/
public int process(String fileName) throws Exception {
filePath = fileName;
this.fs = new POIFSFileSystem(new FileInputStream(fileName));
MissingRecordAwareHSSFListener listener = new MissingRecordAwareHSSFListener(this);
formatListener = new FormatTrackingHSSFListener(listener);
HSSFEventFactory factory = new HSSFEventFactory();
HSSFRequest request = new HSSFRequest();
if (outputFormulaValues) {
request.addListenerForAllRecords(formatListener);
} else {
workbookBuildingListener = new EventWorkbookBuilder.SheetRecordCollectingListener(formatListener);
request.addListenerForAllRecords(workbookBuildingListener);
}
factory.processWorkbookEvents(request, fs);
return totalRows; //返回该excel文件的总行数，不包括首列和空行
}
public List<List<String>> process(InputStream in) throws Exception {
//filePath = fileName;
this.fs = new POIFSFileSystem(in);
MissingRecordAwareHSSFListener listener = new MissingRecordAwareHSSFListener(this);
formatListener = new FormatTrackingHSSFListener(listener);
HSSFEventFactory factory = new HSSFEventFactory();
HSSFRequest request = new HSSFRequest();
if (outputFormulaValues) {
request.addListenerForAllRecords(formatListener);
} else {
workbookBuildingListener = new EventWorkbookBuilder.SheetRecordCollectingListener(formatListener);
request.addListenerForAllRecords(workbookBuildingListener);
}
factory.processWorkbookEvents(request, fs);
return dataList; //返回该excel文件的总行数，不包括首列和空行
}
/**
* HSSFListener 监听方法，处理Record
* 处理每个单元格
* @param record
*/
@SuppressWarnings("unchecked")
public void processRecord(Record record) {
int thisRow = -1;
int thisColumn = -1;
String thisStr = null;
String value = null;
switch (record.getSid()) {
case BoundSheetRecord.sid:
boundSheetRecords.add(record);
break;
case BOFRecord.sid: //开始处理每个sheet
BOFRecord br = (BOFRecord) record;
if (br.getType() == BOFRecord.TYPE_WORKSHEET) {
//如果有需要，则建立子工作簿
if (workbookBuildingListener != null && stubWorkbook == null) {
stubWorkbook = workbookBuildingListener.getStubHSSFWorkbook();
}
if (orderedBSRs == null) {
orderedBSRs = BoundSheetRecord.orderByBofPosition(boundSheetRecords);
}
sheetName = orderedBSRs[sheetIndex].getSheetname();
sheetIndex++;
}
break;
case SSTRecord.sid:
sstRecord = (SSTRecord) record;
break;
case BlankRecord.sid: //单元格为空白
BlankRecord brec = (BlankRecord) record;
thisRow = brec.getRow();
thisColumn = brec.getColumn();
thisStr = "";
cellList.add(thisColumn, thisStr);
break;
case BoolErrRecord.sid: //单元格为布尔类型
BoolErrRecord berec = (BoolErrRecord) record;
thisRow = berec.getRow();
thisColumn = berec.getColumn();
thisStr = berec.getBooleanValue() + "";
cellList.add(thisColumn, thisStr);
checkRowIsNull(thisStr); //如果里面某个单元格含有值，则标识该行不为空行
break;
case FormulaRecord.sid://单元格为公式类型
FormulaRecord frec = (FormulaRecord) record;
thisRow = frec.getRow();
thisColumn = frec.getColumn();
if (outputFormulaValues) {
if (Double.isNaN(frec.getValue())) {
outputNextStringRecord = true;
nextRow = frec.getRow();
nextColumn = frec.getColumn();
} else {
thisStr = '"' + HSSFFormulaParser.toFormulaString(stubWorkbook, frec.getParsedExpression()) + '"';
}
} else {
thisStr = '"' + HSSFFormulaParser.toFormulaString(stubWorkbook, frec.getParsedExpression()) + '"';
}
cellList.add(thisColumn, thisStr);
checkRowIsNull(thisStr); //如果里面某个单元格含有值，则标识该行不为空行
break;
case StringRecord.sid: //单元格中公式的字符串
if (outputNextStringRecord) {
StringRecord srec = (StringRecord) record;
thisStr = srec.getString();
thisRow = nextRow;
thisColumn = nextColumn;
outputNextStringRecord = false;
}
break;
case LabelRecord.sid:
LabelRecord lrec = (LabelRecord) record;
curRow = thisRow = lrec.getRow();
thisColumn = lrec.getColumn();
value = lrec.getValue().trim();
value = value.equals("") ? "" : value;
cellList.add(thisColumn, value);
checkRowIsNull(value); //如果里面某个单元格含有值，则标识该行不为空行
break;
case LabelSSTRecord.sid: //单元格为字符串类型
LabelSSTRecord lsrec = (LabelSSTRecord) record;
curRow = thisRow = lsrec.getRow();
thisColumn = lsrec.getColumn();
if (sstRecord == null) {
cellList.add(thisColumn, "");
} else {
value = sstRecord.getString(lsrec.getSSTIndex()).toString().trim();
value = value.equals("") ? "" : value;
cellList.add(thisColumn, value);
checkRowIsNull(value); //如果里面某个单元格含有值，则标识该行不为空行
}
break;
case NumberRecord.sid: //单元格为数字类型
NumberRecord numrec = (NumberRecord) record;
curRow = thisRow = numrec.getRow();
thisColumn = numrec.getColumn();
//第一种方式
//value = formatListener.formatNumberDateCell(numrec).trim();//这个被写死，采用的m/d/yy h:mm格式，不符合要求
//第二种方式，参照formatNumberDateCell里面的实现方法编写
Double valueDouble=((NumberRecord)numrec).getValue();
String formatString=formatListener.getFormatString(numrec);
if (formatString.contains("m/d/yy")){
formatString="yyyy-MM-dd hh:mm:ss";
}
int formatIndex=formatListener.getFormatIndex(numrec);
value=formatter.formatRawCellContents(valueDouble, formatIndex, formatString).trim();
value = value.equals("") ? "" : value;
//向容器加入列值
cellList.add(thisColumn, value);
checkRowIsNull(value); //如果里面某个单元格含有值，则标识该行不为空行
break;
default:
break;
}
//遇到新行的操作
if (thisRow != -1 && thisRow != lastRowNumber) {
lastColumnNumber = -1;
}
//空值的操作
if (record instanceof MissingCellDummyRecord) {
MissingCellDummyRecord mc = (MissingCellDummyRecord) record;
curRow = thisRow = mc.getRow();
thisColumn = mc.getColumn();
cellList.add(thisColumn, "");
}
//更新行和列的值
if (thisRow > -1)
lastRowNumber = thisRow;
if (thisColumn > -1)
lastColumnNumber = thisColumn;
//行结束时的操作
if (record instanceof LastCellOfRowDummyRecord) {
if (minColums > 0) {
//列值重新置空
if (lastColumnNumber == -1) {
lastColumnNumber = 0;
}
}
lastColumnNumber = -1;
if (flag&&curRow!=0) { //该行不为空行且该行不是第一行，发送（第一行为列名，不需要）
//ExcelReaderUtil.sendRows(filePath, sheetName, sheetIndex, curRow + 1, cellList); //每行结束时，调用sendRows()方法
totalRows++;
//添加到数据集合中
dataList.add(cellList);
}
//清空容器
cellList = new ArrayList<String>();
//cellList.clear();
flag=false;
}
}
/**
* 如果里面某个单元格含有值，则标识该行不为空行
* @param value
*/
public void checkRowIsNull(String value){
if (value != null && !"".equals(value)) {
flag = true;
}
}
}
读取xlsx格式数据（自动获取表头长度方式）：
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.ss.usermodel.BuiltinFormats;
import org.apache.poi.ss.usermodel.DataFormatter;
import org.apache.poi.xssf.eventusermodel.XSSFReader;
import org.apache.poi.xssf.model.SharedStringsTable;
import org.apache.poi.xssf.model.StylesTable;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
/**
* @desc POI读取excel有两种模式，一种是用户模式，一种是事件驱动模式
* 采用SAX事件驱动模式解决XLSX文件，可以有效解决用户模式内存溢出的问题，
* 该模式是POI官方推荐的读取大数据的模式，
* 在用户模式下，数据量较大，Sheet较多，或者是有很多无用的空行的情况下，容易出现内存溢出
* <p>
* 用于解决.xlsx2007版本大数据量问题
**/
public class ExcelXlsxReader extends DefaultHandler {
//存储所有数据
private List<List<String>> dataList = new ArrayList<List<String>>();
/**
* 单元格中的数据可能的数据类型
*/
enum CellDataType {
BOOL, ERROR, FORMULA, INLINESTR, SSTINDEX, NUMBER, DATE, NULL
}
/**
* 共享字符串表
*/
private SharedStringsTable sst;
/**
* 上一次的索引值
*/
private String lastIndex;
/**
* 文件的绝对路径
*/
private String filePath = "";
/**
* 工作表索引
*/
private int sheetIndex = 0;
/**
* sheet名
*/
private String sheetName = "";
/**
* 总行数
*/
private int totalRows=0;
/**
* 一行内cell集合
*/
private List<String> cellList = new ArrayList<String>();
/**
* 判断整行是否为空行的标记
*/
private boolean flag = false;
/**
* 当前行
*/
private int curRow = 1;
/**
* 当前列
*/
private int curCol = 0;
/**
* T元素标识
*/
private boolean isTElement;
/**
* 判断上一单元格是否为文本空单元格
*/
private boolean startElementFlag = true;
private boolean endElementFlag = false;
private boolean charactersFlag = false;
/**
* 异常信息，如果为空则表示没有异常
*/
private String exceptionMessage;
/**
* 单元格数据类型，默认为字符串类型
*/
private CellDataType nextDataType = CellDataType.SSTINDEX;
private final DataFormatter formatter = new DataFormatter();
/**
* 单元格日期格式的索引
*/
private short formatIndex;
/**
* 日期格式字符串
*/
private String formatString;
//定义前一个元素和当前元素的位置，用来计算其中空的单元格数量，如A6和A8等
private String prePreRef = "A", preRef = null, ref = null;
//定义该文档一行最大的单元格数，用来补全一行最后可能缺失的单元格
private String maxRef = null;
/**
* 单元格
*/
private StylesTable stylesTable;
/**
* 遍历工作簿中所有的电子表格
* 并缓存在mySheetList中
*
* @param filename
* @throws Exception
*/
public int process(String filename) throws Exception {
filePath = filename;
OPCPackage pkg = OPCPackage.open(filename);
XSSFReader xssfReader = new XSSFReader(pkg);
stylesTable = xssfReader.getStylesTable();
SharedStringsTable sst = xssfReader.getSharedStringsTable();
XMLReader parser = XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
this.sst = sst;
parser.setContentHandler(this);
XSSFReader.SheetIterator sheets = (XSSFReader.SheetIterator) xssfReader.getSheetsData();
while (sheets.hasNext()) { //遍历sheet
curRow = 1; //标记初始行为第一行
sheetIndex++;
InputStream sheet = sheets.next(); //sheets.next()和sheets.getSheetName()不能换位置，否则sheetName报错
sheetName = sheets.getSheetName();
InputSource sheetSource = new InputSource(sheet);
parser.parse(sheetSource); //解析excel的每条记录，在这个过程中startElement()、characters()、endElement()这三个函数会依次执行
sheet.close();
}
return totalRows; //返回该excel文件的总行数，不包括首列和空行
}
public List<List<String>> process(InputStream in) throws Exception {
//filePath = filename;
OPCPackage pkg = OPCPackage.open(in);
XSSFReader xssfReader = new XSSFReader(pkg);
stylesTable = xssfReader.getStylesTable();
SharedStringsTable sst = xssfReader.getSharedStringsTable();
//XMLReader parser = XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
XMLReader parser = XMLReaderFactory.createXMLReader();
this.sst = sst;
parser.setContentHandler(this);
XSSFReader.SheetIterator sheets = (XSSFReader.SheetIterator) xssfReader.getSheetsData();
while (sheets.hasNext()) { //遍历sheet
curRow = 1; //标记初始行为第一行
sheetIndex++;
InputStream sheet = sheets.next(); //sheets.next()和sheets.getSheetName()不能换位置，否则sheetName报错
sheetName = sheets.getSheetName();
InputSource sheetSource = new InputSource(sheet);
parser.parse(sheetSource); //解析excel的每条记录，在这个过程中startElement()、characters()、endElement()这三个函数会依次执行
sheet.close();
}
return dataList;
}
/**
* 第一个执行
*
* @param uri
* @param localName
* @param name
* @param attributes
* @throws SAXException
*/
@Override
public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {
//c => 单元格
if ("c".equals(name)) {
//前一个单元格的位置
if (preRef == null) {
preRef = attributes.getValue("r");
} else {
//中部文本空单元格标识 ‘endElementFlag' 判断前一次是否为文本空字符串，true则表明不是文本空字符串，false表明是文本空字符串跳过把空字符串的位置赋予preRef
if (endElementFlag){
preRef = ref;
}
}
//当前单元格的位置
ref = attributes.getValue("r");
//首部文本空单元格标识 ‘startElementFlag' 判断前一次，即首部是否为文本空字符串，true则表明不是文本空字符串，false表明是文本空字符串, 且已知当前格，即第二格带“B”标志，则ref赋予preRef
if (!startElementFlag && !flag){ //上一个单元格为文本空单元格，执行下面的，使ref=preRef；flag为true表明该单元格之前有数据值，即该单元格不是首部空单元格，则跳过
// 这里只有上一个单元格为文本空单元格，且之前的几个单元格都没有值才会执行
preRef = ref;
}
//设定单元格类型
this.setNextDataType(attributes);
endElementFlag = false;
charactersFlag = false;
startElementFlag = false;
}
//当元素为t时
if ("t".equals(name)) {
isTElement = true;
} else {
isTElement = false;
}
//置空
lastIndex = "";
}
/**
* 第二个执行
* 得到单元格对应的索引值或是内容值
* 如果单元格类型是字符串、INLINESTR、数字、日期，lastIndex则是索引值
* 如果单元格类型是布尔值、错误、公式，lastIndex则是内容值
* @param ch
* @param start
* @param length
* @throws SAXException
*/
@Override
public void characters(char[] ch, int start, int length) throws SAXException {
startElementFlag = true;
charactersFlag = true;
lastIndex += new String(ch, start, length);
}
/**
* 第三个执行
*
* @param uri
* @param localName
* @param name
* @throws SAXException
*/
@Override
public void endElement(String uri, String localName, String name) throws SAXException {
//t元素也包含字符串
if (isTElement) {
//将单元格内容加入rowlist中，在这之前先去掉字符串前后的空白符
String value = lastIndex.trim();
cellList.add(curCol, value);
endElementFlag = true;
curCol++;
isTElement = false;
//如果里面某个单元格含有值，则标识该行不为空行
if (value != null && !"".equals(value)) {
flag = true;
}
} else if ("v".equals(name)) {
//v => 单元格的值，如果单元格是字符串，则v标签的值为该字符串在SST中的索引
String value = this.getDataValue(lastIndex.trim(), "");//根据索引值获取对应的单元格值
//补全单元格之间的空单元格
if (!ref.equals(preRef)) {
int len = countNullCell(ref, preRef);
for (int i = 0; i < len; i++) {
cellList.add(curCol, "");
curCol++;
}
} else if (ref.equals(preRef) && !ref.startsWith("A")){ //ref等于preRef，且以B或者C...开头，表明首部为空格
int len = countNullCell(ref, "A");
for (int i = 0; i <= len; i++) {
cellList.add(curCol, "");
curCol++;
}
}
cellList.add(curCol, value);
curCol++;
endElementFlag = true;
//如果里面某个单元格含有值，则标识该行不为空行
if (value != null && !"".equals(value)) {
flag = true;
}
} else {
//如果标签名称为row，这说明已到行尾，调用optRows()方法
if ("row".equals(name)) {
//默认第一行为表头，以该行单元格数目为最大数目
if (curRow == 1) {
maxRef = ref;
}
//补全一行尾部可能缺失的单元格
if (maxRef != null) {
int len = -1;
//前一单元格，true则不是文本空字符串，false则是文本空字符串
if (charactersFlag){
len = countNullCell(maxRef, ref);
}else {
len = countNullCell(maxRef, preRef);
}
for (int i = 0; i <= len; i++) {
cellList.add(curCol, "");
curCol++;
}
}
if (flag&&curRow!=1){ //该行不为空行且该行不是第一行，则发送（第一行为列名，不需要）
//ExcelReaderUtil.sendRows(filePath, sheetName, sheetIndex, curRow, cellList);
totalRows++;
//添加到数据集合中
dataList.add(cellList);
}
//清空容器
cellList = new ArrayList<String>();
//cellList.clear();
curRow++;
curCol = 0;
preRef = null;
prePreRef = null;
ref = null;
flag=false;
}
}
}
/**
* 处理数据类型
*
* @param attributes
*/
public void setNextDataType(Attributes attributes) {
nextDataType = CellDataType.NUMBER; //cellType为空，则表示该单元格类型为数字
formatIndex = -1;
formatString = null;
String cellType = attributes.getValue("t"); //单元格类型
String cellStyleStr = attributes.getValue("s"); //
String columnData = attributes.getValue("r"); //获取单元格的位置，如A1,B1
if ("b".equals(cellType)) { //处理布尔值
nextDataType = CellDataType.BOOL;
} else if ("e".equals(cellType)) { //处理错误
nextDataType = CellDataType.ERROR;
} else if ("inlineStr".equals(cellType)) {
nextDataType = CellDataType.INLINESTR;
} else if ("s".equals(cellType)) { //处理字符串
nextDataType = CellDataType.SSTINDEX;
} else if ("str".equals(cellType)) {
nextDataType = CellDataType.FORMULA;
}
if (cellStyleStr != null) { //处理日期
int styleIndex = Integer.parseInt(cellStyleStr);
XSSFCellStyle style = stylesTable.getStyleAt(styleIndex);
formatIndex = style.getDataFormat();
formatString = style.getDataFormatString();
if (formatString.contains("m/d/yyyy") || formatString.contains("yyyy/mm/dd")|| formatString.contains("yyyy/m/d") ) {
nextDataType = CellDataType.DATE;
formatString = "yyyy-MM-dd hh:mm:ss";
}
if (formatString == null) {
nextDataType = CellDataType.NULL;
formatString = BuiltinFormats.getBuiltinFormat(formatIndex);
}
}
}
/**
* 对解析出来的数据进行类型处理
* @param value 单元格的值，
* value代表解析：BOOL的为0或1， ERROR的为内容值，FORMULA的为内容值，INLINESTR的为索引值需转换为内容值，
* SSTINDEX的为索引值需转换为内容值， NUMBER为内容值，DATE为内容值
* @param thisStr 一个空字符串
* @return
*/
@SuppressWarnings("deprecation")
public String getDataValue(String value, String thisStr) {
switch (nextDataType) {
// 这几个的顺序不能随便交换，交换了很可能会导致数据错误
case BOOL: //布尔值
char first = value.charAt(0);
thisStr = first == '0' ? "FALSE" : "TRUE";
break;
case ERROR: //错误
thisStr = "\"ERROR:" + value.toString() + '"';
break;
case FORMULA: //公式
thisStr = '"' + value.toString() + '"';
break;
case INLINESTR:
XSSFRichTextString rtsi = new XSSFRichTextString(value.toString());
thisStr = rtsi.toString();
rtsi = null;
break;
case SSTINDEX: //字符串
String sstIndex = value.toString();
try {
int idx = Integer.parseInt(sstIndex);
XSSFRichTextString rtss = new XSSFRichTextString(sst.getEntryAt(idx));//根据idx索引值获取内容值
thisStr = rtss.toString();
//System.out.println(thisStr);
//有些字符串是文本格式的，但内容却是日期
rtss = null;
} catch (NumberFormatException ex) {
thisStr = value.toString();
}
break;
case NUMBER: //数字
if (formatString != null) {
thisStr = formatter.formatRawCellContents(Double.parseDouble(value), formatIndex, formatString).trim();
} else {
thisStr = value;
}
thisStr = thisStr.replace("_", "").trim();
break;
case DATE: //日期
thisStr = formatter.formatRawCellContents(Double.parseDouble(value), formatIndex, formatString);
// 对日期字符串作特殊处理，去掉T
thisStr = thisStr.replace("T", " ");
break;
default:
thisStr = " ";
break;
}
return thisStr;
}
public int countNullCell(String ref, String preRef) {
//excel2007最大行数是1048576，最大列数是16384，最后一列列名是XFD
String xfd = ref.replaceAll("\\d+", "");
String xfd_1 = preRef.replaceAll("\\d+", "");
xfd = fillChar(xfd, 3, '@', true);
xfd_1 = fillChar(xfd_1, 3, '@', true);
char[] letter = xfd.toCharArray();
char[] letter_1 = xfd_1.toCharArray();
int res = (letter[0] - letter_1[0]) * 26 * 26 + (letter[1] - letter_1[1]) * 26 + (letter[2] - letter_1[2]);
return res - 1;
}
public String fillChar(String str, int len, char let, boolean isPre) {
int len_1 = str.length();
if (len_1 < len) {
if (isPre) {
for (int i = 0; i < (len - len_1); i++) {
str = let + str;
}
} else {
for (int i = 0; i < (len - len_1); i++) {
str = str + let;
}
}
}
return str;
}
/**
* @return the exceptionMessage
*/
public String getExceptionMessage() {
return exceptionMessage;
}
}
读取工具类：
import java.io.InputStream;
import java.util.List;
public class ExcelReaderUtil {
//excel2003扩展名
public static final String EXCEL03_EXTENSION = ".xls";
//excel2007扩展名
public static final String EXCEL07_EXTENSION = ".xlsx";
//读取xls格式
public static List<List<String>> readExcelXls(InputStream in) throws Exception {
ExcelXlsReader excelXls=new ExcelXlsReader();
List<List<String>> dataList =excelXls.process(in);
return dataList;
}
//读取xlsx格式
public static List<List<String>> readExcelXlsx(InputStream in) throws Exception {
ExcelXlsxReader excelXls=new ExcelXlsxReader();
List<List<String>> dataList =excelXls.process(in);
return dataList;
}
public static void readExcel(String fileName) throws Exception {
int totalRows =0;
if (fileName.endsWith(EXCEL03_EXTENSION)) { //处理excel2003文件
ExcelXlsReader excelXls=new ExcelXlsReader();
totalRows =excelXls.process(fileName);
} else if (fileName.endsWith(EXCEL07_EXTENSION)) {//处理excel2007文件
ExcelXlsxReader excelXlsxReader = new ExcelXlsxReader();
totalRows = excelXlsxReader.process(fileName);
} else {
throw new Exception("文件格式错误，fileName的扩展名只能是xls或xlsx。");
}
System.out.println("发送的总行数：" + totalRows);
}
public static void main(String[] args) throws Exception {
String path="C:\\test.xlsx";
ExcelReaderUtil.readExcel(path);
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持呐喊教程。
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