1、Excel导入
1）读取文件
2）转换Workbook
3）拼装数据集
String filePath = "excle/20171207.xls";
String fullPath = Thread.currentThread().getContextClassLoader().getResource(filePath).getPath();
Workbook wb = null;
try {
InputStream in = new BufferedInputStream(new FileInputStream(fullPath));
wb = WorkbookFactory.create(in);
} catch (FileNotFoundException e) {
e.printStackTrace();
throw new RuntimeException(e);
} catch (InvalidFormatException e) {
e.printStackTrace();
throw new RuntimeException(e);
} catch (IOException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
List<String[]> list = new ArrayList<String[]>();
for (int sheetIndex = 0; sheetIndex < wb.getNumberOfSheets(); sheetIndex++){
Sheet st = wb.getSheetAt(sheetIndex);
// 第一行为标题，不取
for (int rowIndex = 0; rowIndex <= st.getPhysicalNumberOfRows(); rowIndex++){
Row row = st.getRow(rowIndex);
if (row == null) {
continue;
}
String[] cells = cellArray(row);
list.add(cells);
}
}
2、Excel导出
1）声明一个工作薄
2）设置样式
3）设置字体
4）设置表格标题行
5）生成表格具体数据行，超过上限生成下一个sheet
6）利用反射获取对应的属性值并赋值到表格
7）判断值的类型后进行格式转换（日期，浮点数特殊格式处理）
private static Pattern NUMBER_PATTERN = Pattern.compile("^//d+(//.//d+)?$");
public <T> byte[] exportExcel(String title, String[] headers, Collection<T> dataSet, String pattern) {
// 声明一个工作薄
SXSSFWorkbook workbook = new SXSSFWorkbook(10000);
// 生成一个表格
// 生成一个样式
CellStyle style = workbook.createCellStyle();
// 设置这些样式
style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);
style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
style.setBorderBottom(BorderStyle.THIN);
style.setBorderLeft(BorderStyle.THIN);
style.setBorderRight(BorderStyle.THIN);
style.setBorderTop(BorderStyle.THIN);
style.setAlignment(HorizontalAlignment.CENTER);
// 生成一个字体
Font font = workbook.createFont();
font.setColor(HSSFColor.VIOLET.index);
font.setFontHeightInPoints((short) 12);
font.setBold(true);
// 把字体应用到当前的样式
style.setFont(font);
Font font2 = workbook.createFont();
Sheet sheet = null;
Row row = null;
int index = 0;
int sheetnum = 0;
Iterator<T> it = dataSet.iterator();
// 生成表格标题行
sheet = workbook.createSheet(title + sheetnum);
sheet.setDefaultColumnWidth(15);
row = sheet.createRow(0);
for (int i = 0; i < headers.length; i++) {
Cell cell = row.createCell(i);
cell.setCellStyle(style);
XSSFRichTextString text = new XSSFRichTextString(headers[i]);
cell.setCellValue(text);
}
ByteArrayOutputStream baos = null;
try {
// 生成表格具体数据行
while (it.hasNext()) {
index++;
// 如果数据大于5000行，生成下一个sheet
if (index > 50000) {
index = 0;
++sheetnum;
sheet = workbook.createSheet(title + sheetnum);
sheet.setDefaultColumnWidth(15);
row = sheet.createRow(0);
for (int i = 0; i < headers.length; i++) {
Cell cell = row.createCell(i);
cell.setCellStyle(style);
XSSFRichTextString text = new XSSFRichTextString(headers[i]);
cell.setCellValue(text);
}
}
row = sheet.createRow(index);
T t = (T) it.next();
// 利用反射，根据javabean属性的先后顺序，动态调用getXxx()方法得到属性值
Field[] fields = t.getClass().getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
Cell cell = row.createCell(i);
cell.setCellStyle(style);
Field field = fields[i];
String fieldName = field.getName();
Object value = PropertyUtils.getProperty(t, fieldName);
// 判断值的类型后进行强制类型转换
String textValue = null;
if (value instanceof Integer) {
int intValue = (Integer) value;
cell.setCellValue(intValue);
} else if (value instanceof Float) {
float fValue = (Float) value;
textValue = new XSSFRichTextString(
String.valueOf(fValue)).toString();
cell.setCellValue(textValue);
} else if (value instanceof Double) {
double dValue = (Double) value;
textValue = new XSSFRichTextString(
String.valueOf(dValue)).toString();
cell.setCellValue(textValue);
} else if (value instanceof Long) {
long longValue = (Long) value;
cell.setCellValue(longValue);
}
if (value instanceof Boolean) {
boolean bValue = (Boolean) value;
textValue = "true";
if (!bValue) {
textValue = "false";
}
} else if (value instanceof Date) {
Date date = (Date) value;
if ("".equals(pattern)) {
pattern = "yyy-MM-dd";
}
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
textValue = sdf.format(date);
} else {
if (null == value || "".equals(value)) {
value = "";
} else {
textValue = value.toString();
}
}
// 如果不是图片数据，就利用正则表达式判断textValue是否全部由数字组成
if (textValue != null) {
Pattern p = NUMBER_PATTERN;
Matcher matcher = p.matcher(textValue);
if (matcher.matches()) {
// 是数字当作double处理
cell.setCellValue(Double.parseDouble(textValue));
} else {
XSSFRichTextString richString = new XSSFRichTextString(
textValue);
font2.setColor(HSSFColor.BLUE.index);
richString.applyFont(font2);
cell.setCellValue(richString);
}
}
}
}
baos = new ByteArrayOutputStream();
workbook.write(baos);
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException("poi处理出错");
} finally{
try {
workbook.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return baos.toByteArray();
}
