生成 Excel
/**
* 生成 Excel 文件
*/
public static void makeDataToExcel() {
//生成 Excel 表格
HSSFWorkbook hssfWorkbook = new HSSFWorkbook();
HSSFSheet sheet = hssfWorkbook.createSheet();
for (int i = 0; i < DAY_NUM + 1; i++) {
sheet.setColumnWidth(i, 3000);
}
Calendar cal = Calendar.getInstance();
//创建头一行 (表头)
HSSFRow row0 = sheet.createRow(0);
row0.setHeight((short) 500);
HSSFCell cell;
for (int i = 0; i < DAY_NUM; i++) {
cell = row0.createCell(i);
cell.setCellValue(new HSSFRichTextString(new SimpleDateFormat("yyyy-MM-dd").format(cal.getTime())));
cal.add(Calendar.DATE, -1);
}
String[] strings = new String[DAY_NUM];
for (int i = 0; i < DAY_NUM; i++) {
strings[i] = i + ":SKysOnG";
}
List<Object> rows = new ArrayList<>();
for (int i = 0; i < DAY_NUM; i++) {
rows.add(strings);
}
for (int i = 0; i < rows.size(); i++) {
HSSFRow row = sheet.createRow(i + 1);
String[] hang = (String[]) rows.get(i);
for (int j = 0; j < hang.length; j++) {
cell = row.createCell(j);
cell.setCellValue(new HSSFRichTextString(hang[j]));
}
}
try {
FileOutputStream os = new FileOutputStream(fileName);
hssfWorkbook.write(os);
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
读取 Excel
/**
* 从 Excel 文件 中读取 数据
*/
@SuppressWarnings("ALL")
private static void getDataFromExcel() throws Exception {
FileInputStream inputStream = new FileInputStream(fileName);
Sheet sheet = null;
/** 读取要和生成 用同一个生成类,
* 这里我们用的是 HSSFWorkbook (还有一种:XSSFWorkbook)
* 但在实际项目中,我们可能会从多个渠道获得文件,
* 此时的文件生成类就有可能不统一了。注意定好规则。
*/
HSSFWorkbook hwb = new HSSFWorkbook(inputStream);
//获得 sheet
sheet = hwb.getSheetAt(0);
if (sheet != null) {
// sheet.getLastRowNum() 获得最后一行下标
// 从第二行开始(i = 1),向下遍历每一行。
for (int i = 1; i <= sheet.getLastRowNum(); i++) {
Row row = sheet.getRow(i);
if (row == null) continue;
for (int j = 0; j < row.getLastCellNum(); j++){
Cell cell0 = row.getCell(j);
System.out.print(cell0.getStringCellValue());
}
System.out.println();
}
}
}
注意 读取时用的 Excel生成类 保持一致。