我的要求是使用Apache POI将HashMap写入excel，hashmap中的键是我的cell-id，hashmap中的值是要设置到该单元格中的值。 以下是我的代码：
public static final String[] ExcelColumns = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O",
"P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "AA", "AB", "AC", "AD", "AE", "AF", "AG", "AH", "AI",
"AJ", "AK", "AL", "AM", "AN", "AO", "AP", "AQ", "AR", "AS", "AT", "AU", "AV", "AW", "AX", "AY", "AZ", "BA",
"BB", "BC", "BD", "BE", "BF", "BG", "BH", "BI", "BJ", "BK", "BL", "BM", "BN", "BO", "BP", "BQ", "BR", "BS",
"BT", "BU", "BV", "BW", "BX", "BY", "BZ", "CA", "CB", "CC", "CD", "CE", "CF", "CG", "CH", "CI", "CJ", "CK", "CL", "CM",
"CN", "CO", "CP", "CQ", "CR", "CS", "CT", "CU", "CV", "CW", "CX", "CY", "CZ", "DA", "DB", "DC", "DD", "DE", "DF", "DG",
"DH", "DI", "DJ", "DK", "DL", "DM", "DN", "DO", "DP", "DQ", "DR", "DS", "DT", "DU", "DV", "DW", "DX", "DY", "DZ"};
public static int row(Map.Entry pair) {
//System.out.println("The row is:"+k);
return new Integer(pair.getKey().toString().substring(1));
}
public static int column(Map.Entry pair) {
String indexVal = pair.getKey().toString().substring(0, 1);
String[] ExcelColumns = CompareExcelDAO.ExcelColumns;
int index = 0;
for (int i = 0; i < ExcelColumns.length; ++i) {
if (indexVal.equals(ExcelColumns[i])) {
index = i;
}
}
return index+1;
}
public void CopyContentsOfExcel(HSSFWorkbook workbook, HSSFSheet sheet,
String ExcelPath_1, int i, HashMap getMismatchMap)
throws IOException {
int rownum = sheet.getLastRowNum()+2; // to check last used row in Excel
//CompareExcelDAO mapDao = new CompareExcelDAO();
Iterator it1 = getMismatchMap.entrySet().iterator();
while (it1.hasNext()) {
Map.Entry pair = (Map.Entry) it1.next();
int r = row(pair) + rownum;
int c= column(pair);
System.out.println("c = "+c+" r = "+r);
System.out.println("Key: "+pair.getKey()+" "+"Value: "+pair.getValue());
sheet.createRow(r).createCell(c).setCellValue(pair.getValue().toString());
}}
问题是它只将一对键/值打印到两个固定单元格中，在调试模式下，所有行/列值都按预期显示，但是当我打开工作表时，只打印一个值。 http://www.tagwith.com/question_1103031_printing-a-hashmap-to-excel-using-jxl-api，此站点提供了一种使用jxl将Hashmap写入Excel的方法，但我的所有项目都使用Apache POI。
答案 0 :(得分：0)
我不确定如何为多行提供散列映射。我有类似的问题，如下所示。我将创建一个类似于ColumnName和ColumnValue的地图，我会将其添加到多个列的地图中。然后将类似的多个行的地图映射到List，并且我将它写为excel文件。你可以试试这个。
public static void main(String[] p) throws Exception{
List<Map<String, String>> collection = new ArrayList<>();
Map<String, String> row1 = new LinkedHashMap<>();
row1.put("ID","1");
row1.put("Name","pop");
collection.add(row1);
Map<String, String> row2 = new LinkedHashMap<>();
row2.put("ID","2");
row2.put("Name","lop");
collection.add(row2);
writeCollection(new File("excel1.xlsx"),"sheet1",collection);
}
private static void writeCollection(File file, String sheetName, List<Map<String, String>> collection) throws Exception {
try {
FileInputStream fileInputStream = new FileInputStream(file);
XSSFWorkbook workBook = new XSSFWorkbook(fileInputStream);
XSSFSheet sheet = workBook.getSheet(sheetName);
int rows = sheet.getLastRowNum();
fileInputStream.close();
rows = rows + 1;
for (int index = 0; index < collection.size(); index++) {
XSSFRow row = sheet.createRow(rows++);
Map<String, String> rowObject = collection.get(index);
for (String columnName : rowObject.keySet()) {
int cellIndex = getColumnIndex(sheet, columnName);
if (cellIndex != -1) {
XSSFCell cell = row.createCell(cellIndex);
cell.setCellValue(rowObject.get(columnName));
}
}
}
FileOutputStream out = new FileOutputStream(file);
workBook.write(out);
out.close();
} catch (Exception e) {
throw e;
}
}
public static int getColumnIndex(XSSFSheet sheet, String columnName) {
int columnIndex = -1;
try {
int colNum = sheet.getRow(0).getLastCellNum();
XSSFRow firstRow = sheet.getRow(0);
for (int colIndex = 0; colIndex < colNum; colIndex++) {
XSSFCell cell = firstRow.getCell(colIndex);
if (cell.toString().equals(columnName)) {
columnIndex = colIndex;
}
}
} catch (Exception e) {
throw e;
}
return columnIndex;
}
答案 1 :(得分：0)
如果你想比较两个excel并在第三个中写出差异， 创建一个新的工作簿和工作表，并将其传递给一个方法，您可以打开两个Excel，并比较下面的内容：
while (file1cellIterator.hasNext()&& file2cellIterator.hasNext()) {
Cell file1cell = (Cell) file1cellIterator.next();
Cell file2cell = (Cell) file2cellIterator.next();
org.apache.poi.ss.usermodel.Cell cell = row.createCell(cellnum++);
switch (file1cell.getCellType()) {
case Cell.CELL_TYPE_BOOLEAN:
if ((file1cell.getBooleanCellValue())==(file2cell.getBooleanCellValue())){
((org.apache.poi.ss.usermodel.Cell) cell).setCellValue(file1cell.getBooleanCellValue());
}
else if((file1cell.getBooleanCellValue())!=(file2cell.getBooleanCellValue())){
((org.apache.poi.ss.usermodel.Cell) cell).setCellValue(file1cell.getBooleanCellValue());
}
break;
case Cell.CELL_TYPE_NUMERIC:
if ((file1cell.getNumericCellValue())==(file2cell.getNumericCellValue())){
((org.apache.poi.ss.usermodel.Cell) cell).setCellValue(file1cell.getNumericCellValue());
}
else if((file1cell.getNumericCellValue())!=(file2cell.getNumericCellValue())){
((org.apache.poi.ss.usermodel.Cell) cell).setCellValue((file1cell.getNumericCellValue())-(file2cell.getNumericCellValue()));
}
break;
case Cell.CELL_TYPE_STRING:
if ((file1cell.getStringCellValue())==(file2cell.getStringCellValue())){
((org.apache.poi.ss.usermodel.Cell) cell).setCellValue(file1cell.getStringCellValue());
}
else if((file1cell.getStringCellValue())!=(file2cell.getStringCellValue())){
((org.apache.poi.ss.usermodel.Cell) cell).setCellValue((file1cell.getStringCellValue())+(file2cell.getStringCellValue()));
}
break;
default:
((org.apache.poi.ss.usermodel.Cell) cell)
.setCellValue(file1cell.getStringCellValue());
break;
}
}
}