这是对旧问题的增强：Read empty cell using Apache POI Event model。
实际上我正在尝试读取空单元格，当空单元格出现在中间或结束列时，它会起作用。但是，如果第一列包含空单元格，则不会在下面的代码中将其视为BlankRecord.sid。由于这个原因，该单元格的值被设置为空字符串。我想将第一列也视为BlankRecord，以便将其设置为null。
以下是xls的代码：
public void processRecord(Record record) {
int thisRow = -1;
String thisStr = null;
switch (record.getSid()) {
case BoundSheetRecord.sid:
boundSheetRecords.add(record);
break;
case BOFRecord.sid:
BOFRecord br = (BOFRecord)record;
if(br.getType() == BOFRecord.TYPE_WORKSHEET) {
// Works by ordering the BSRs by the location of their BOFRecords, and then knowing that we
// process BOFRecords in byte offset order
if(orderedBSRs == null) {
orderedBSRs = BoundSheetRecord.orderByBofPosition(boundSheetRecords);
}
// Check the existence of sheets
if(sheetIndex == 0) {
for(int i=0;i<excelSheetList.length;i++) {
boolean found = false;
for(int j=0;j<orderedBSRs.length;j++) {
if(this.getExcelSheetSpecification().equals(MSExcelAdapter.USE_WORKSHEET_NAME)) {
String sheetName = ((BoundSheetRecord) boundSheetRecords.get(j)).getSheetname();
if(excelSheetList[i].equals(sheetName)) {
found = true;
break;
}
} else {
try {
if(Integer.parseInt(excelSheetList[i]) == j) {
found = true;
break;
}
} catch (NumberFormatException e) {
}
}
}
if(!found)
this.warning("processRecord()","Sheet: " + excelSheetList[i] + " does not exist.");
}
}
readCurrentSheet = true;
sheetIndex++;
if(this.getExcelSheetSpecification().equals(MSExcelAdapter.USE_WORKSHEET_NAME)) {
String sheetName = ((BoundSheetRecord) boundSheetRecords.get(sheetIndex-1)).getSheetname();
if(!canRead(sheetName)) {
readCurrentSheet = false;
}
} else {
if(!canRead(sheetIndex + "")) {
readCurrentSheet = false;
}
}
}
break;
case SSTRecord.sid:
sstRecord = (SSTRecord) record;
break;
case BlankRecord.sid:
BlankRecord brec = (BlankRecord) record;
thisRow = brec.getRow();
thisStr = null;
values.add(thisStr);
columnCount++;
break;
case FormulaRecord.sid:
FormulaRecord frec = (FormulaRecord) record;
thisRow = frec.getRow();
if(Double.isNaN( frec.getValue() )) {
// Formula result is a string
// This is stored in the next record
outputNextStringRecord = true;
nextRow = frec.getRow();
} else {
thisStr = formatListener.formatNumberDateCell(frec);
}
break;
case StringRecord.sid:
if(outputNextStringRecord) {
// String for formula
StringRecord srec = (StringRecord)record;
thisStr = srec.getString();
thisRow = nextRow;
outputNextStringRecord = false;
}
break;
case LabelSSTRecord.sid:
if(readCurrentSheet) {
LabelSSTRecord lsrec = (LabelSSTRecord) record;
thisRow = lsrec.getRow() + 1;
if(rowNumberList.contains(thisRow + "") ||
(rowNumberList.contains(END_OF_ROWS) && thisRow >= secondLastRow)) {
if(sstRecord == null) {
thisStr = "(No SST Record, can't identify string)";
} else {
thisStr = sstRecord.getString(lsrec.getSSTIndex()).toString();
}
}
}
break;
case NumberRecord.sid:
if(readCurrentSheet) {
NumberRecord numrec = (NumberRecord) record;
thisRow = numrec.getRow() + 1;
if(rowNumberList.contains(thisRow + "") ||
(rowNumberList.contains(END_OF_ROWS) && thisRow >= secondLastRow)) {
thisStr = formatListener.formatNumberDateCell(numrec); // Format
}
}
break;
default:
break;
}
// Handle missing column
if(record instanceof MissingCellDummyRecord) {
thisStr = "";
}
// If we got something to print out, do so
if(thisStr != null) {
values.add(thisStr);
columnCount++;
}
// Handle end of row
if(record instanceof LastCellOfRowDummyRecord) {
.....
}
...
使用xlsx，如果第一列有空单元格，则跳过它。这是xlsx的代码：
/**
* Default handler for parsing an excel sheet
* @see org.xml.sax.helpers.DefaultHandler
*/
private class SheetHandler extends DefaultHandler {
private SharedStringsTable sst;
private String lastContents;
private boolean nextIsString;
private MSExcelReader reader;
private int thisColumn = -1;
private int lastColumnNumber = -1; // The last column printed to the output stream
private SheetHandler(SharedStringsTable sst, MSExcelReader reader) {
this.sst = sst;
this.reader = reader;
}
public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {
// c => cell
if(name.equals("c")) {
// Figure out if the value is an index in the SST
String cellType = attributes.getValue("t");
if(cellType != null && cellType.equals("s")) {
nextIsString = true;
} else {
nextIsString = false;
}
// 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));
}
// Clear contents cache
lastContents = "";
}
public void endElement(String uri, String localName, String name) throws SAXException {
// Process the last contents as required.
// Do now, as characters() may be called more than once
if(nextIsString) {
try {
int idx = Integer.parseInt(lastContents);
lastContents = new XSSFRichTextString(sst.getEntryAt(idx)).toString();
} catch (NumberFormatException e) {
}
}
// v => contents of a cell
// Output after we've seen the string contents
if(name.equals("v")) {
for (int i = lastColumnNumber; i < thisColumn - 1; ++i)
values.add(null); // Add empty string for missing columns
values.add(lastContents);
// Update column
if (thisColumn > -1)
lastColumnNumber = thisColumn;
}
if(name.equals("row")) {
...
与我提出的旧问题相同：我没有使用usermodel（org.apache.poi.ss.usermodel），而是使用Event API来处理xls和xlsx文件。
我正在实现HSSFListener并覆盖xls文件的processRecord（记录记录）方法。对于xlsx文件，我使用的是javax.xml.parsers.SAXParser和org.xml.sax.XMLReader。
我正在使用JDK7和Apache POI 3.7。有人可以帮忙吗？
我有excel文件，其中包含以下列： -
Column1 Column2 Column3 Column4 Column5 Column6 Column7
Parag Joshi Pune 100
Parag Joshi Pune 200
当我在excel中打印所有值时，我的代码生成的输出是： -
;Parag;Joshi;Pune;null;100;null
;Parag;Joshi;Pune;200;null;null
见上文，它为第一列打印了空字符串，但对于其他columnd，它打印了值null。我希望第一列打印相同的值null。
答案 0 :(得分：0)
如果你的方式比这更清洁，请指教，谢谢！
创建一个ArrayList来存储columnIndex;
ArrayList<Integer> listAllColInRow = new ArrayList<>();
创建一个ArrayList来存储您的数据;
addDataToRow = new ArrayList<>();
将每个columnIndex添加到listAllColInRow;
while (cells.hasNext()) {
cell = (HSSFCell) cells.next();
int col = cell.getColumnIndex();
listAllColInRow.add(col);
}
获取每行中的第一个Column索引，以便我们检查它是否是第一列;
Integer a = listAllColInRow.get(0);
如果它不是第一列，则在您的arrayList的第一个索引中添加null，在此示例中为addDataToRow，依此类推，直到它到达第一列;
// while a is not the 1st column
while( a != 0){
//add null to the 1st index of the ArrayList
addDataToRow.add(0,null);
a--;
}