POI 操作Excel表格系列4 --- 创建Excel表格填充数据并下载

从web页面将数据库的数据读取出来，填充到Excel（2007+）表格里面，并讲表格下载到本地。
思路： 后台读取数据库 ---> 填充到Excel表格 ---> Excel表格存储到临时文件夹 ---> 从临时文件夹下载

jsp代码

<a class="btn btn-primary" type="button" id="download-excel">Download Excel Menu</a>

JavaScript代码

$('#download-excel').click(function(){
$.ajax({
url: 'createTempExcel',
type: 'post',
dataType: 'json',
success: function(data){
if(data.status == 'fail'){
alert('error');
}else{
window.location.href = "downloadExcel?fileName="+data.fileName;
}
}

});

});

controller处理代码

@RequestMapping(value = "/createTempExcel", method = RequestMethod.POST, produces = "application/json; charset=utf-8")
@ResponseBody
public Map<String, Object> createTempExcel(HttpServletRequest request) {
Map<String, Object> result = new HashMap<String, Object>();
// --- 数据库读取数据 存储到Excel保存到临时文件夹 ---
String tempPath = request.getServletContext().getInitParameter("tempPath");
File dir = new File(tempAbsolutePath);
if (!dir.exists()) {
dir.mkdirs();
}
String fileName = new Date().getTime() ++ ".xlsx";

List<Document> docs = new ArrayList<Document>();
//--- docs 填充数据库的数据 ---
result = ExcelXSSFUtils.createExcel(docs, tempAbsolutePath, fileName);
if (result.get("status").equals("fail")) {
return result;
}

result.put("fileName", fileName);
return result;
}

@RequestMapping(value = "/downloadExcel")
public void downloadExcel(HttpServletRequest request, HttpServletResponse response) throws IOException {
String fileName = request.getParameter("fileName");
String tempPath = request.getServletContext().getInitParameter("tempPath");
// --- 从临时文件夹下载 ---
response.setHeader("content-disposition", "attachment;filename=xxx.xlsx");
response.setContentType("application/octet-stream; charset=utf-8");
FileInputStream in = new FileInputStream(tempAbsolutePath + fileName);
OutputStream out = response.getOutputStream();
byte buffer[] = new byte[1024];
int len = 0;
while ((len = in.read(buffer)) > 0) {
out.write(buffer, 0, len);
}
in.close();
out.close();
}

Excel创建工具类

/**
*
*
* @param data
*            数据库数据
* @param tempPath
*            临时文件夹路径
* @param fileName
*            文件名
* @return
*/
public static Map<String, Object> createExcel(List<Document> data, String tempPath, String fileName) {
Map<String, Object> result = new HashMap<String, Object>();
String[] textList = { "true", "false" };

XSSFWorkbook  wb = new XSSFWorkbook();
XSSFSheet sheet = wb.createSheet();
XSSFRow row = null;
XSSFCell cell = null;

// --- rowHeader ---
row = sheet.createRow(0);
cell = row.createCell(0);
//-- 类似设置header ---

// --- 数据有效性 下拉框选择 ---
DataValidationHelper helper = new XSSFDataValidationHelper((XSSFSheet) sheet);
XSSFDataValidationConstraint constraintBoolean = new XSSFDataValidationConstraint(textList);
CellRangeAddressList regionsBoolean = new CellRangeAddressList(1, 500, 6, 11);
DataValidation validationBoolean = helper.createValidation(constraintBoolean, regionsBoolean);
validationBoolean.createErrorBox("输入值有误", "请从下拉框选择");
validationBoolean.setShowErrorBox(true);
sheet.addValidationData(validationBoolean);

// --- 数据有效性 只允许输入整数 ---
DataValidationConstraint constraintNum = new XSSFDataValidationConstraint(
DataValidationConstraint.ValidationType.INTEGER,
DataValidationConstraint.OperatorType.GREATER_OR_EQUAL, "0");
CellRangeAddressList regionNumber = new CellRangeAddressList(1, 500, 4, 5);
DataValidation validationNum = helper.createValidation(constraintNum, regionNumber);
validationNum.createErrorBox("输入值类型出错", "数值型,请输入大于或等于0的整数值");
validationNum.setShowErrorBox(true);
sheet.addValidationData(validationNum);

// --- 数据有效性 只允许输入小数 ---
DataValidationConstraint constraintDecimal = new XSSFDataValidationConstraint(
DataValidationConstraint.ValidationType.DECIMAL,
DataValidationConstraint.OperatorType.GREATER_OR_EQUAL, "0");
CellRangeAddressList regionDecimal = new CellRangeAddressList(1, 500, 3, 3);
DataValidation validationDecimal = helper.createValidation(constraintDecimal, regionDecimal);
validationDecimal.createErrorBox("输入值类型出错", "数值型,请输入大于或等于0的小数值");
validationDecimal.setShowErrorBox(true);
sheet.addValidationData(validationDecimal);

for (int i = 0; i < menuItems.size(); i++) {
XSSFCellStyle cellStyle = wb.createCellStyle();
XSSFColor xssfColor = new XSSFColor();
Document item = menuItems.get(i);

// --- get cell value ---
String code = data.getString("code");
String color = "FF"
+ (item.getString("color") != null ? item.getString("color").substring(1,
item.getString("color").length()) : "FFFFFF");
//--- 以下是从该数据库data获取的数据 ---
xssfColor.setARGBHex(color);
cellStyle.setFillForegroundColor(xssfColor);
cellStyle.setFillPattern(CellStyle.SOLID_FOREGROUND);
cellStyle.setBorderBottom(CellStyle.BORDER_THIN); // 下边框
cellStyle.setBorderLeft(CellStyle.BORDER_THIN);// 左边框
cellStyle.setBorderTop(CellStyle.BORDER_THIN);// 上边框
cellStyle.setBorderRight(CellStyle.BORDER_THIN);// 右边框

// --- insert cell value ---
row = sheet.createRow(i + 1);
cell = row.createCell(0);
cell.setCellStyle(cellStyle);
cell.setCellValue(code);
}

FileOutputStream out;
try {
out = new FileOutputStream(tempPath + fileName);
wb.write(out);
out.close();
} catch (FileNotFoundException e) {
result.put("status", "fail");
result.put("message", "Database Error.");
return result;
} catch (IOException e) {
result.put("status", "fail");
result.put("message", "Database Error.");
return result;
}

result.put("status", "success");
return result;

}