POI是一个apache开源的jar包，可以通过搜索 java POI找到官网，并下载开发包.

包含的功能：

可以读取excel2003,2007,2010等。

读取excel2007/2010的代码：

public static boolean isNumeric(String str) {
    for (int i = 0; i < str.length(); i++) {
        if (!Character.isDigit(str.charAt(i))) {
            return false;
        }
    }
    return true;
}

public static List<List<String>> readXlsx(String path) throws Exception {
    InputStream is = new FileInputStream(path);
    @SuppressWarnings("resource")
    XSSFWorkbook xssfWorkbook = new XSSFWorkbook(is);
    List<List<String>> result = new ArrayList<>();

    for (int sheetIx = 0; sheetIx < xssfWorkbook.getNumberOfSheets(); sheetIx++) {
        XSSFSheet xssfSheet = xssfWorkbook.getSheetAt(sheetIx);
        if (xssfSheet == null)
            continue;

        for (int rowNum = 1; rowNum <= xssfSheet.getLastRowNum(); rowNum++) {
            XSSFRow xssfRow = xssfSheet.getRow(rowNum);

            int minColIx = xssfRow.getFirstCellNum();
            int maxColIx = xssfRow.getLastCellNum();
            List<String> rowList = new ArrayList<>();
            for (int colIx = minColIx; colIx < maxColIx; colIx++) {
                XSSFCell cell = xssfRow.getCell(colIx);
                if (cell == null)
                    continue;
                rowList.add(cell.toString());
            }
            result.add(rowList);
        }
    }
    return result;
}