Apache POI 是创建和维护操作各种符合Office Open XML（OOXML）标准和微软的OLE 2复合文档格式（OLE2）的Java API。用它可以使用Java读取和创建,修改MS Excel文件.而且,还可以使用Java读取和创建MS Word和MSPowerPoint文件。Apache POI 提供Java操作Excel解决方案（适用于Excel97-2008）。
简单理解就是通过POI，java可以与office建立联系。
本次项目实践基于SSM框架，简单封装了Excel批量导入导出功能，实现过程如下
1. maven导入java包：
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.5-FINAL</version>
</dependency>
2. 建立Excel实体--ExcelBean
/**
*
* @Description: 导入导出excel
* @author haipeng
* @date 2017年4月11日
*/
public class ExcelBean implements java.io.Serializable {
private String headTextName;//列头（标题）名
private String propertyName;//对应字段名
private Integer cols;//合并单元格数
private XSSFCellStyle cellStyle;
public ExcelBean(){
}
public ExcelBean(String headTextName, String propertyName){
this.headTextName = headTextName;
this.propertyName = propertyName;
}
public ExcelBean(String headTextName, String propertyName, Integer cols) {
super();
this.headTextName = headTextName;
this.propertyName = propertyName;
this.cols = cols;
}
public String getHeadTextName() {
return headTextName;
}
public void setHeadTextName(String headTextName) {
this.headTextName = headTextName;
}
public String getPropertyName() {
return propertyName;
}
public void setPropertyName(String propertyName) {
this.propertyName = propertyName;
}
public Integer getCols() {
return cols;
}
public void setCols(Integer cols) {
this.cols = cols;
}
public XSSFCellStyle getCellStyle() {
return cellStyle;
}
public void setCellStyle(XSSFCellStyle cellStyle) {
this.cellStyle = cellStyle;
}
}
3. 封装Excel工具类--ExcelUtils
public class ExcelUtils {
private final static String excel2003L =".xls"; //2003- 版本的excel
private final static String excel2007U =".xlsx"; //2007+ 版本的excel
/*************************************文件上传****************************/
public static List<List<Object>> getBankListByExcel(InputStream in,String fileName) throws Exception{
List<List<Object>> list = null;
//创建Excel工作薄
Workbook work = getWorkbook(in,fileName);
if(null == work){
throw new Exception("创建Excel工作薄为空！");
}
Sheet sheet = null;
Row row = null;
Cell cell = null;
list = new ArrayList<List<Object>>();
//遍历Excel中所有的sheet
for (int i = 0; i < work.getNumberOfSheets(); i++) {
sheet = work.getSheetAt(i);
if(sheet==null){continue;}
//遍历当前sheet中的所有行
for (int j = sheet.getFirstRowNum(); j < sheet.getLastRowNum(); j++) {
row = sheet.getRow(j);
if(row==null||row.getFirstCellNum()==j){continue;}
//遍历所有的列
List<Object> li = new ArrayList<Object>();
for (int y = row.getFirstCellNum(); y < row.getLastCellNum(); y++) {
cell = row.getCell(y);
li.add(getCellValue(cell));
}
list.add(li);
}
}
// work.close();
return list;
}
/**
* 描述：根据文件后缀，自适应上传文件的版本
* @param inStr,fileName
* @return
* @throws Exception
*/
public static Workbook getWorkbook(InputStream inStr,String fileName) throws Exception{
Workbook wb = null;
String fileType = fileName.substring(fileName.lastIndexOf("."));
if(excel2003L.equals(fileType)){
wb = new HSSFWorkbook(inStr); //2003-
}else if(excel2007U.equals(fileType)){
wb = new XSSFWorkbook(inStr); //2007+
}else{
throw new Exception("解析的文件格式有误！");
}
return wb;
}
/**
* 描述：对表格中数值进行格式化
* @param cell
* @return
*/
public static Object getCellValue(Cell cell){
Object value = null;
DecimalFormat df = new DecimalFormat("0"); //格式化number String字符
SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd"); //日期格式化
DecimalFormat df2 = new DecimalFormat("0.00"); //格式化数字
switch (cell.getCellType()) {
case Cell.CELL_TYPE_STRING:
value = cell.getRichStringCellValue().getString();
break;
case Cell.CELL_TYPE_NUMERIC:
if("General".equals(cell.getCellStyle().getDataFormatString())){
value = df.format(cell.getNumericCellValue());
}else if("m/d/yy".equals(cell.getCellStyle().getDataFormatString())){
value = sdf.format(cell.getDateCellValue());
}else{
value = df2.format(cell.getNumericCellValue());
}
break;
case Cell.CELL_TYPE_BOOLEAN:
value = cell.getBooleanCellValue();
break;
case Cell.CELL_TYPE_BLANK:
value = "";
break;
default:
break;
}
return value;
}
/****************************************上传结束***************************************
/**
* 多列头创建EXCEL
*
* @param sheetName 工作簿名称
* @param clazz 数据源model类型
* @param objs excel标题列以及对应model字段名
* @param map 标题列行数以及cell字体样式
* @return
* @throws IllegalArgumentException
* @throws IllegalAccessException
* @throws InvocationTargetException
* @throws ClassNotFoundException
* @throws IntrospectionException
* @throws ParseException
*/
public static XSSFWorkbook createExcelFile(Class clazz, List objs,Map<Integer, List<ExcelBean>> map,String sheetName) throws IllegalArgumentException,IllegalAccessException,
InvocationTargetException, ClassNotFoundException, IntrospectionException, ParseException{
// 创建新的Excel 工作簿
XSSFWorkbook workbook = new XSSFWorkbook();
// 在Excel工作簿中建一工作表，其名为缺省值, 也可以指定Sheet名称
XSSFSheet sheet = workbook.createSheet(sheetName);
// 以下为excel的字体样式以及excel的标题与内容的创建，下面会具体分析;
createFont(workbook);//字体样式
createTableHeader(sheet, map);//创建标题（头）
createTableRows(sheet, map, objs, clazz);//创建内容
return workbook;
}
private static XSSFCellStyle fontStyle;
private static XSSFCellStyle fontStyle2;
public static void createFont(XSSFWorkbook workbook) {
// 表头
fontStyle = workbook.createCellStyle();
XSSFFont font1 = workbook.createFont();
font1.setBoldweight(XSSFFont.BOLDWEIGHT_BOLD);
font1.setFontName("黑体");
font1.setFontHeightInPoints((short) 14);// 设置字体大小
fontStyle.setFont(font1);
fontStyle.setBorderBottom(XSSFCellStyle.BORDER_THIN); // 下边框
fontStyle.setBorderLeft(XSSFCellStyle.BORDER_THIN);// 左边框
fontStyle.setBorderTop(XSSFCellStyle.BORDER_THIN);// 上边框
fontStyle.setBorderRight(XSSFCellStyle.BORDER_THIN);// 右边框
fontStyle.setAlignment(XSSFCellStyle.ALIGN_CENTER); // 居中
// 内容
fontStyle2=workbook.createCellStyle();
XSSFFont font2 = workbook.createFont();
font2.setFontName("宋体");
font2.setFontHeightInPoints((short) 10);// 设置字体大小
fontStyle2.setFont(font2);
fontStyle2.setBorderBottom(XSSFCellStyle.BORDER_THIN); // 下边框
fontStyle2.setBorderLeft(XSSFCellStyle.BORDER_THIN);// 左边框
fontStyle2.setBorderTop(XSSFCellStyle.BORDER_THIN);// 上边框
fontStyle2.setBorderRight(XSSFCellStyle.BORDER_THIN);// 右边框
fontStyle2.setAlignment(XSSFCellStyle.ALIGN_CENTER); // 居中
}
/**
* 根据ExcelMapping 生成列头（多行列头）
*
* @param sheet
* 工作簿
* @param map
* 每行每个单元格对应的列头信息
*/
public static final void createTableHeader(XSSFSheet sheet, Map<Integer, List<ExcelBean>> map) {
int startIndex=0;//cell起始位置
int endIndex=0;//cell终止位置
for (Map.Entry<Integer, List<ExcelBean>> entry : map.entrySet()) {
XSSFRow row = sheet.createRow(entry.getKey());
List<ExcelBean> excels = entry.getValue();
for (int x = 0; x < excels.size(); x++) {
//合并单元格
if(excels.get(x).getCols()>1){
if(x==0){
endIndex+=excels.get(x).getCols()-1;
CellRangeAddress range=new CellRangeAddress(0,0,startIndex,endIndex);
sheet.addMergedRegion(range);
startIndex+=excels.get(x).getCols();
}else{
endIndex+=excels.get(x).getCols();
CellRangeAddress range=new CellRangeAddress(0,0,startIndex,endIndex);
sheet.addMergedRegion(range);
startIndex+=excels.get(x).getCols();
}
XSSFCell cell = row.createCell(startIndex-excels.get(x).getCols());
cell.setCellValue(excels.get(x).getHeadTextName());// 设置内容
if (excels.get(x).getCellStyle() != null) {
cell.setCellStyle(excels.get(x).getCellStyle());// 设置格式
}
cell.setCellStyle(fontStyle);
}else{
XSSFCell cell = row.createCell(x);
cell.setCellValue(excels.get(x).getHeadTextName());// 设置内容
if (excels.get(x).getCellStyle() != null) {
cell.setCellStyle(excels.get(x).getCellStyle());// 设置格式
}
cell.setCellStyle(fontStyle);
}
}
}
}
/**
*
* @param sheet
* @param map
* @param objs
* @param clazz
*/
@SuppressWarnings("rawtypes")
public static void createTableRows(XSSFSheet sheet, Map<Integer, List<ExcelBean>> map, List objs, Class clazz)
throws IllegalArgumentException, IllegalAccessException, InvocationTargetException, IntrospectionException,
ClassNotFoundException, ParseException {
int rowindex = map.size();
int maxKey = 0;
List<ExcelBean> ems = new ArrayList<>();
for (Map.Entry<Integer, List<ExcelBean>> entry : map.entrySet()) {
if (entry.getKey() > maxKey) {
maxKey = entry.getKey();
}
}
ems = map.get(maxKey);
List<Integer> widths = new ArrayList<Integer>(ems.size());
for (Object obj : objs) {
XSSFRow row = sheet.createRow(rowindex);
for (int i = 0; i < ems.size(); i++) {
ExcelBean em = (ExcelBean) ems.get(i);
// 获得get方法
PropertyDescriptor pd = new PropertyDescriptor(em.getPropertyName(), clazz);
Method getMethod = pd.getReadMethod();
Object rtn = getMethod.invoke(obj);
String value = "";
// 如果是日期类型 进行 转换
if (rtn != null) {
if (rtn instanceof Date) {
value = DateUtils.date2String((Date) rtn,"yyyy-MM-dd");
} else if(rtn instanceof BigDecimal){
NumberFormat nf = new DecimalFormat("#,##0.00");
value=nf.format((BigDecimal)rtn).toString();
} else if((rtn instanceof Integer) && (Integer.valueOf(rtn.toString())<0 )){
value="--";
}else {
value = rtn.toString();
}
}
XSSFCell cell = row.createCell(i);
cell.setCellValue(value);
cell.setCellType(XSSFCell.CELL_TYPE_STRING);
cell.setCellStyle(fontStyle2);
// 获得最大列宽
int width = value.getBytes().length * 300;
// 还未设置，设置当前
if (widths.size() <= i) {
widths.add(width);
continue;
}
// 比原来大，更新数据
if (width > widths.get(i)) {
widths.set(i, width);
}
}
rowindex++;
}
// 设置列宽
for (int index = 0; index < widths.size(); index++) {
Integer width = widths.get(index);
width = width < 2500 ? 2500 : width + 300;
width = width > 10000 ? 10000 + 300 : width + 300;
sheet.setColumnWidth(index, width);
}
}
}
4. 在HTML页面导入需要的js
<script type="text/javascript" src="${ctxPath}/js/jquery-form.js"></script>
5. 在HTML添加测试控件
<form id="uploadForm" enctype="multipart/form-data" method="post">
<input id="upfile" type="file" name="upfile">
<input type="button" value="导入" id="upLoadPayerCreditInfoExcel" name="btn">
</form>
<a href="${ctxPath}/creditInfo/downLoadReceverCreditInfoExcel.html">导出</a>
6. 导出通过a标签的get请求即可以实现，导入则通过ajax的post请求实现：
$('#upLoadPayerCreditInfoExcel').click(function(){
var cacheVersion=$("#cacheVersion").val();
if(checkData()){
$('#uploadForm').ajaxSubmit({
url:$("#root").val()+'/creditInfo/uploadReceiverCreditInfoExcel.html',
data:{'cacheVersion':cacheVersion},
dataType: 'text'
});
}
});
//JS校验form表单信息
function checkData(){
var fileDir = $("#upfile").val();
var suffix = fileDir.substr(fileDir.lastIndexOf("."));
if("" == fileDir){
alert("选择需要导入的Excel文件！");
return false;
}
if(".xls" != suffix && ".xlsx" != suffix ){
alert("选择Excel格式的文件导入！");
return false;
}
return true;
}
7. controller端实现
导出：
@RequestMapping(value = "/downLoadPayerCreditInfoExcel", method = RequestMethod.GET)
@ResponseBody
public void downLoadPayerCreditInfoExcel(HttpServletRequest request,HttpServletResponse response,HttpSession session){
response.reset();
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddhhmmssms");
String dateStr = sdf.format(new Date());
Long companyId=UserUtils.getCompanyIdBySession(session);
Map<String,Object> map=new HashMap<String,Object>();
// 指定下载的文件名
response.setHeader("Content-Disposition", "attachment;filename=" +dateStr+".xlsx");
response.setContentType("application/vnd.ms-excel;charset=UTF-8");
response.setHeader("Pragma", "no-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
XSSFWorkbook workbook=null;
try {
//导出Excel对象
workbook = creditInfoService.exportPayerCreditInfoExcel(companyId);
} catch (IllegalArgumentException | IllegalAccessException
| InvocationTargetException | ClassNotFoundException
| IntrospectionException | ParseException e1) {
e1.printStackTrace();
}
OutputStream output;
try {
output = response.getOutputStream();
BufferedOutputStream bufferedOutPut = new BufferedOutputStream(output);
bufferedOutPut.flush();
workbook.write(bufferedOutPut);
bufferedOutPut.close();
} catch (IOException e) {
e.printStackTrace();
}
}
@ResponseBody
@RequestMapping(value="uploadPayerCreditInfoExcel",method={RequestMethod.GET,RequestMethod.POST})
Public void uploadPayerCreditInfoExcel(HttpServletRequest request,HttpServletResponse response,HttpSession session) throws Exception {
MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
MultipartFile file = multipartRequest.getFile("upfile");
if(file.isEmpty()){
throw new Exception("文件不存在！");
}
Long companyId=UserUtils.getCompanyIdBySession(session);
Long userId=UserUtils.getUserIdBySession(session);
InputStream in = file.getInputStream();
creditInfoService.uploadPayerCreditInfoExcel(in,file,companyId,userId);
in.close();
PrintWriter out = null;
response.setCharacterEncoding("utf-8"); //防止ajax接受到的中文信息乱码
out = response.getWriter();
out.print("文件导入成功！");
out.flush();
out.close();
}
8、service层
导入，从excel中获得数据放入List<List<object>>中，然后遍历放入实体，执行插入操作：
public void uploadPayerCreditInfoExcel(InputStream in, MultipartFile file,Long companyId,Long userId) throws Exception {
List<List<Object>> listob = ExcelUtils.getBankListByExcel(in,file.getOriginalFilename());
List<CreditInfoBean> creditInfoList=new ArrayList<CreditInfoBean>();
for (int i = 0; i < listob.size(); i++) {
List<Object> ob = listob.get(i);
CreditInfoBean creditInfoBean = new CreditInfoBean();
creditInfoBean.setCompanyName(String.valueOf(ob.get(0)));
creditInfoBean.setBillType(String.valueOf(ob.get(1)));
creditInfoBean.setBillNumber(String.valueOf(ob.get(2)));
BigDecimal bd=new BigDecimal(String.valueOf(ob.get(3)));
creditInfoBean.setBuyerBillAmount(bd.setScale(2, BigDecimal.ROUND_HALF_UP));
creditInfoBean.setReceiveTime(String.valueOf(ob.get(4)));
creditInfoBean.setBuyerRemark(String.valueOf(ob.get(5)));
creditInfoList.add(creditInfoBean);
}
}
导出：
public XSSFWorkbook exportPayerCreditInfoExcel(Long companyId) throws IllegalArgumentException, IllegalAccessException, InvocationTargetException, ClassNotFoundException, IntrospectionException, com.sun.tools.example.debug.expr.ParseException {
List<CreditInfoBean> creditInfoList=creditInfoDao.listAllPayerCreditInfoPage(companyId);
List<ExcelBean> ems=new ArrayList<>();
Map<Integer,List<ExcelBean>>map=new LinkedHashMap<>();
XSSFWorkbook book=null;
ems.add(new ExcelBean("供应商名称","companyName",0));
ems.add(new ExcelBean("票据类型","billType",0));
ems.add(new ExcelBean("票据号","billNumber",0));
// ems.add(new ExcelBean("买方是否参与","isBuyerIquidation",0));
ems.add(new ExcelBean("票据金额","buyerBillAmount",0));
ems.add(new ExcelBean("应付日期","buyerPayTime",0));
ems.add(new ExcelBean("剩余天数","overplusDays",0));
ems.add(new ExcelBean("状态","buyerBillStatus",0));
map.put(0, ems);
List<CreditInfoBean> afterChangeList=changeBuyerStatus(creditInfoList);
book=ExcelUtils.createExcelFile(CreditInfoBean.class, afterChangeList, map, "应付账款信息");
return book;
}