我已使用Apache POI库将.xls文件转换为csv文件。我迭代每一行和单元格，放一个逗号，并附加到缓冲的阅读器。单元格数字和字符串完全转换。如果有空白单元格，我会输入逗号，但代码不会检测到空白值。怎么做？请帮帮我。
import java.io.*;
import java.util.Iterator;
import java.text.DateFormat;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.math.BigDecimal;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.ss.usermodel.DateUtil;
class convert {
static void convertToXls(File inputFile, File outputFile)
{
StringBuffer cellDData = new StringBuffer();
String cellDDataString=null;
try
{
FileOutputStream fos = new FileOutputStream(outputFile);
HSSFWorkbook workbook = new HSSFWorkbook(new FileInputStream(inputFile));
HSSFSheet sheet = workbook.getSheetAt(0);
Cell cell=null;
Row row;
int previousCell;
int currentCell;
Iterator<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext())
{
previousCell = -1;
currentCell = 0;
row = rowIterator.next();
System.out.println("ROW:-->");
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext())
{
// System.out.println("true" +cellIterator.hasNext());
cell = cellIterator.next();
currentCell = cell.getColumnIndex();
System.out.println("CELL:-->" +cell.toString());
try{
switch (cell.getCellType())
{
case Cell.CELL_TYPE_BOOLEAN:
cellDData.append(cell.getBooleanCellValue() + ",");
System.out.println("boo"+ cell.getBooleanCellValue());
break;
case Cell.CELL_TYPE_NUMERIC:
if (DateUtil.isCellDateFormatted(cell))
{
// System.out.println(cell.getDateCellValue());
SimpleDateFormat dateFormat = new SimpleDateFormat(
"dd/MM/yyyy");
String strCellValue = dateFormat.format(cell.getDateCellValue());
// System.out.println("date:"+strCellValue);
cellDData.append(strCellValue +",");
}
else {
System.out.println(cell.getNumericCellValue());
Double value = cell.getNumericCellValue();
Long longValue = value.longValue();
String strCellValue1 = new String(longValue.toString());
// System.out.println("number:"+strCellValue1);
cellDData.append(strCellValue1 +",");
}
// cellDData.append(cell.getNumericCellValue() + ",");
//String i=(new java.text.DecimalFormat("0").format( cell.getNumericCellValue()+"," ));
//System.out.println("number"+cell.getNumericCellValue());
break;
case Cell.CELL_TYPE_STRING:
String out=cell.getRichStringCellValue().getString();
cellDData.append(cell.getRichStringCellValue().getString() + ",");
//System.out.println("string"+cell.getStringCellValue());
break;
case Cell.CELL_TYPE_BLANK:
cellDData.append("" + "THIS IS BLANK");
System.out.print("THIS IS BLANK");
break;
default:
break;
}}
catch (NullPointerException e) {
//do something clever with the exception
System.out.println("nullException"+e.getMessage());
}
}
int len=cellDData.length() - 1;
// System.out.println("length:"+len);
// System.out.println("length1:"+cellDData.length());
cellDData.replace(cellDData.length() - 1, cellDData.length() , "");
cellDData.append("\n");
}
//cellDData.append("\n");
//String out=cellDData.toString();
//System.out.println("res"+out);
//String o = out.substring(0, out.lastIndexOf(","));
//System.out.println("final"+o);
fos.write(cellDData.toString().getBytes());
//fos.write(cellDDataString.getBytes());
fos.close();
}
catch (FileNotFoundException e)
{
System.err.println("Exception" + e.getMessage());
}
catch (IOException e)
{
System.err.println("Exception" + e.getMessage());
}
}
public static void main(String[] args) throws IOException
{
File inputFile = new File("/bwdev/kadfeb/xls/Accredo_Kadmon_Monthly_02282014.xls");
File outputFile = new File("output1.csv");
convertToXls(inputFile, outputFile);
}
答案 0 :(得分：3)
我认为HSSFWorkbook默认会跳过空白单元格或丢失单元格。尝试为HSSFWorkbook对象设置MissingCellPolicy。
可以找到为MissingCellPolicy设置的可能值here
使用行索引和col索引代替Iterator。
HSSFWorkbook workbook = new HSSFWorkbook(new FileInputStream(inputFile));
workbook.setMissingCellPolicy(Row.CREATE_NULL_AS_BLANK);
HSSFSheet sheet = workbook.getSheetAt(0);
for(int rowIndex = sheet.getFirstRowNum(); rowIndex < sheet.getLastRowNum(); rowIndex++)
{
Cell cell=null;
Row row = null;
previousCell = -1;
currentCell = 0;
row = sheet.getRow(rowIndex);
for(int colIndex=row.getFirstCellNum(); colIndex < row.getLastCellNum(); colIndex++)
{
cell = row.getCell(colIndex);
currentCell = cell.getColumnIndex();
/* Cell processing starts here*/
}
}
答案 1 :(得分：1)
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Iterator;
import org.apache.commons.io.FilenameUtils;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class XlsxtoCSV {
static void xlsx(File inputFile, File outputFile) {
// For storing data into CSV files
StringBuffer data = new StringBuffer();
try {
FileOutputStream fos = new FileOutputStream(outputFile);
// Get the workbook object for XLSX file
FileInputStream fis = new FileInputStream(inputFile);
Workbook workbook = null;
String ext = FilenameUtils.getExtension(inputFile.toString());
if (ext.equalsIgnoreCase("xlsx")) {
workbook = new XSSFWorkbook(fis);
} else if (ext.equalsIgnoreCase("xls")) {
workbook = new HSSFWorkbook(fis);
}
// Get first sheet from the workbook
int numberOfSheets = workbook.getNumberOfSheets();
Row row;
Cell cell;
// Iterate through each rows from first sheet
for (int i = 0; i < numberOfSheets; i++) {
Sheet sheet = workbook.getSheetAt(0);
Iterator<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext()) {
row = rowIterator.next();
// For each row, iterate through each columns
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext()) {
cell = cellIterator.next();
switch (cell.getCellType()) {
case Cell.CELL_TYPE_BOOLEAN:
data.append(cell.getBooleanCellValue() + ",");
break;
case Cell.CELL_TYPE_NUMERIC:
data.append(cell.getNumericCellValue() + ",");
break;
case Cell.CELL_TYPE_STRING:
data.append(cell.getStringCellValue() + ",");
break;
case Cell.CELL_TYPE_BLANK:
data.append("" + ",");
break;
default:
data.append(cell + ",");
}
}
data.append('\n'); // appending new line after each row
}
}
fos.write(data.toString().getBytes());
fos.close();
} catch (Exception ioe) {
ioe.printStackTrace();
}
}
// testing the application
public static void main(String[] args) {
// int i=0;
// reading file from desktop
File inputFile = new File(".//src//test//resources//yourExcel.xls"); //provide your path
// writing excel data to csv
File outputFile = new File(".//src//test//resources//yourCSV.csv"); //provide your path
xlsx(inputFile, outputFile);
System.out.println("Conversion of " + inputFile + " to flat file: "
+ outputFile + " is completed");
}
}
答案 2 :(得分：0)
我替换了
while (cellIterator.hasNext()) {
Cell cell = cellIterator.next();
与
for (int cn = 0; cn < row.getLastCellNum(); cn++) {
Cell cell = row.getCell(cn, Row.CREATE_NULL_AS_BLANK);
答案 3 :(得分：0)
使用apache POI将xls / xlsx转换为csv的简单方法。
copy.sort((a, b) => a - b)