我有Java程序,並且希望將數據輸出到Excel電子表格中。我發現我可以使用Apache POI來實現這一點。我嘗試使用發現的例子here,似乎一切正常。但是,我在示例程序中每次迭代(循環)時都無法在Excel中打印新行。使用Apache POI在循環中將數據打印到Excel單元格
這是我的計劃:
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
public class Excel {
public static void main(String[] args) throws Exception {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("Sample sheet");
Map<String, Object[]> data = new HashMap<String, Object[]>();
data.put("1", new Object[] {"Emp No.", "Name", "Salary"});
for (int i=0;i<5;i++){
data.put("2", new Object[] {"5", "Jane", "300"});
}
Set<String> keyset = data.keySet();
int rownum = 0;
for (String key : keyset) {
Row row = sheet.createRow(rownum++);
Object [] objArr = data.get(key);
int cellnum = 0;
for (Object obj : objArr) {
Cell cell = row.createCell(cellnum++);
if(obj instanceof Date)
cell.setCellValue((Date)obj);
else if(obj instanceof Boolean)
cell.setCellValue((Boolean)obj);
else if(obj instanceof String)
cell.setCellValue((String)obj);
else if(obj instanceof Double)
cell.setCellValue((Double)obj);
}
}
try {
FileOutputStream out =
new FileOutputStream(new File("new.xls"));
workbook.write(out);
out.close();
System.out.println("Excel written successfully..");
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Supposely,我想要的輸出是這樣的:
EmpNo Name Salary
5 Jane 300
5 Jane 300
5 Jane 300
5 Jane 300
5 Jane 300
,但它始終只打印第一行中的Excel工作表。任何熟悉使用Apache POI的人都可以幫助我解決這個問題?謝謝!