问题
我想从Java读取和写入一个包含3列和N行的Excel文件，在每个单元格中打印一个字符串。任何人都可以给我简单的代码片段吗？我是否需要使用任何外部库或者Java是否具有内置支持？
我想做以下事情：
for(i=0; i <rows; i++)
//read [i,col1] ,[i,col2], [i,col3]
for(i=0; i<rows; i++)
//write [i,col1], [i,col2], [i,col3]
#1 热门回答(114 赞)
试试Apache POI HSSF。这是一个如何读取excel文件的示例：
try {
POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(file));
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFSheet sheet = wb.getSheetAt(0);
HSSFRow row;
HSSFCell cell;
int rows; // No of rows
rows = sheet.getPhysicalNumberOfRows();
int cols = 0; // No of columns
int tmp = 0;
// This trick ensures that we get the data properly even if it doesn't start from first few rows
for(int i = 0; i < 10 || i < rows; i++) {
row = sheet.getRow(i);
if(row != null) {
tmp = sheet.getRow(i).getPhysicalNumberOfCells();
if(tmp > cols) cols = tmp;
}
}
for(int r = 0; r < rows; r++) {
row = sheet.getRow(r);
if(row != null) {
for(int c = 0; c < cols; c++) {
cell = row.getCell((short)c);
if(cell != null) {
// Your code here
}
}
}
}
} catch(Exception ioe) {
ioe.printStackTrace();
}
在文档页面上，你还可以获得有关如何写入Excel文件的示例。
#2 热门回答(36 赞)
Apache POI可以为你这样做。特别是2162111130模块。 7997889946最有用。这是如何做你想要的 - 特别是创建一个表并写出来。
Workbook wb = new HSSFWorkbook();
//Workbook wb = new XSSFWorkbook();
CreationHelper createHelper = wb.getCreationHelper();
Sheet sheet = wb.createSheet("new sheet");
// Create a row and put some cells in it. Rows are 0 based.
Row row = sheet.createRow((short)0);
// Create a cell and put a value in it.
Cell cell = row.createCell(0);
cell.setCellValue(1);
// Or do it on one line.
row.createCell(1).setCellValue(1.2);
row.createCell(2).setCellValue(
createHelper.createRichTextString("This is a string"));
row.createCell(3).setCellValue(true);
// Write the output to a file
FileOutputStream fileOut = new FileOutputStream("workbook.xls");
wb.write(fileOut);
fileOut.close();
#3 热门回答(31 赞)
首先在项目类路径中添加所有这些jar文件：
- poi-scratchpad-3.7-20101029
- poi-3.2-FINAL-20081019
- poi-3.7-20101029
- poi-examples-3.7-20101029
- poi-ooxml-3.7-20101029
- poi-ooxml-schemas-3.7-20101029
- xmlbeans-2.3.0
- dom4j-1.6.1
在excel文件中写入的代码：
public static void main(String[] args) {
//Blank workbook
XSSFWorkbook workbook = new XSSFWorkbook();
//Create a blank sheet
XSSFSheet sheet = workbook.createSheet("Employee Data");
//This data needs to be written (Object[])
Map<String, Object[]> data = new TreeMap<String, Object[]>();
data.put("1", new Object[]{"ID", "NAME", "LASTNAME"});
data.put("2", new Object[]{1, "Amit", "Shukla"});
data.put("3", new Object[]{2, "Lokesh", "Gupta"});
data.put("4", new Object[]{3, "John", "Adwards"});
data.put("5", new Object[]{4, "Brian", "Schultz"});
//Iterate over data and write to sheet
Set<String> keyset = data.keySet();
int rownum = 0;
for (String key : keyset)
{
//create a row of excelsheet
Row row = sheet.createRow(rownum++);
//get object array of prerticuler key
Object[] objArr = data.get(key);
int cellnum = 0;
for (Object obj : objArr)
{
Cell cell = row.createCell(cellnum++);
if (obj instanceof String)
{
cell.setCellValue((String) obj);
}
else if (obj instanceof Integer)
{
cell.setCellValue((Integer) obj);
}
}
}
try
{
//Write the workbook in file system
FileOutputStream out = new FileOutputStream(new File("C:\\Documents and Settings\\admin\\Desktop\\imp data\\howtodoinjava_demo.xlsx"));
workbook.write(out);
out.close();
System.out.println("howtodoinjava_demo.xlsx written successfully on disk.");
}
catch (Exception e)
{
e.printStackTrace();
}
}
从excel文件中读取的代码
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
public static void main(String[] args) {
try {
FileInputStream file = new FileInputStream(new File("C:\\Documents and Settings\\admin\\Desktop\\imp data\\howtodoinjava_demo.xlsx"));
//Create Workbook instance holding reference to .xlsx file
XSSFWorkbook workbook = new XSSFWorkbook(file);
//Get first/desired sheet from the workbook
XSSFSheet sheet = workbook.getSheetAt(0);
//Iterate through each rows one by one
Iterator<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext())
{
Row row = rowIterator.next();
//For each row, iterate through all the columns
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext())
{
Cell cell = cellIterator.next();
//Check the cell type and format accordingly
switch (cell.getCellType())
{
case Cell.CELL_TYPE_NUMERIC:
System.out.print(cell.getNumericCellValue() + "\t");
break;
case Cell.CELL_TYPE_STRING:
System.out.print(cell.getStringCellValue() + "\t");
break;
}
}
System.out.println("");
}
file.close();
} catch (Exception e) {
e.printStackTrace();
}
}