如果数据量比较大(十万以上)建议导成多个excel文件,之后压缩成zip文件进行下载
//生成一个excel文件
WritableWorkbook wwb = null;
try {
//首先要使用Workbook类的工厂方法创建一个可写入的工作薄(Workbook)对象
wwb = Workbook.createWorkbook(new File(fileName));
} catch (IOException e) {
log.error(e);
}
long totle = service.getTotle(searchParameters);//业务逻辑方法,获取总数,便于在excel分多个工作表
//按65536条数据分页
float res=Float.parseFloat(String.valueOf(totle));
float mus=65536;
float avg=res/mus;
Map cols = (Map) request.getSession().getAttribute("columnsMap"); //业务逻辑方法
for (int i = 0; i < avg+1; i++) {
searchParameters.setEvent_id(String.valueOf(i*mus)); //分页查询条件
searchParameters.setTotalLimit(String.valueOf((i+1)*mus));//分页查询条件
List result = service.getEvents(searchParameters); //分页查询方法
if(wwb!=null){
//创建一个可写入的工作表
//Workbook的createSheet方法有两个参数,第一个是工作表的名称,第二个是工作表在工作薄中的位置
WritableSheet ws = wwb.createSheet("列表"+(i+1), i);
String colss = ((String) cols.get("cols")).substring("selected"
.length() + 1);
String[] columns = colss.split(","); //业务逻辑方法(添加标题)
String[] colNames = ((String) cols.get("colNames")).split(",");
for (int j = 0; j < columns.length; j++) {
jxl.write.WritableFont wfc = new jxl.write.WritableFont(WritableFont.ARIAL,10,WritableFont.NO_BOLD,false,jxl.format.UnderlineStyle.NO_UNDERLINE,jxl.format.Colour.BLACK);
jxl.write.WritableCellFormat wcfFC = new jxl.write.WritableCellFormat(wfc);
wcfFC.setBackground(Colour.GRAY_25);
Label label = new Label(j, 0,colNames[j],wcfFC);
ws.setColumnView(j, 20); //设置列宽
ws.addCell(label); //添加标题
}
String str="";
//下面开始添加单元格
for(int m=0;m<result.size();m++){
for(int j=0;j<columns.length;j++){
Map map = (Map) result.get(m);
//在表格中添加(业务数据)
for (Object key : map.keySet()) {
Object val = map.get(key);
str=String.valueOf(val);
//这里需要注意的是,在Excel中,第一个参数表示列,第二个表示行
Label labelC = new Label(j, m+1, str);
//将生成的单元格添加到工作表中
ws.addCell(labelC);
}
}
}
}
}
//Excel操作完毕之后,关闭所有的操作资源
try {
//从内存中写入文件中
wwb.write();
//关闭资源,释放内存
wwb.close();
} catch (IOException e) {
log.error(e);
} catch (WriteException e) {
log.error(e);
}
//把生成的文件下载
File file = new File(fileName);
if(!file.exists()) throw new Exception("文件不存在!");
FileInputStream fileInputStream = new FileInputStream(file);
BufferedInputStream bufferedInputStream = new BufferedInputStream(fileInputStream);
OutputStream outputStream = response.getOutputStream();
BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);
response.setContentType("application/x-download");
response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode("事件列表.xls", "UTF-8"));
int bytesRead = 0;
byte[] buffer = new byte[8192];
while ((bytesRead = bufferedInputStream.read(buffer, 0, 8192)) != -1) {
bufferedOutputStream.write(buffer, 0, bytesRead);
}
bufferedOutputStream.flush();
fileInputStream.close();
bufferedInputStream.close();
outputStream.close();
bufferedOutputStream.close();
直接代码: