将数据库内容导出为xls文件并传送到web---实现方式显导出为xls，再传送到web，若有直接传送到web，请不吝赐教！

在这个功能实现前，首先要对一些基础知识需要了解

http消息头，请查看这个http://blog.csdn.net/fanyuna/article/details/5568089

实现导出xls需要用到开源的POI，这个相信大家能自己去找到。我再这也附上一个相对较好的教程，不过这个教程只针对写xls，若需要读的话，还需要自己去百度了：
http://www.cnblogs.com/xwdreamer/archive/2011/07/20/2296975.html
写好了这些后需要发送文件了，参考例子：
http://blog.csdn.net/xtj332/article/details/25701411
经过上面几个链接的学习，我估计也差不多了，废话不多说了，直接上代码<span style="white-space:pre"> </span>/**
<span style="white-space:pre"> </span> *
<span style="white-space:pre"> </span> * 
<span style="white-space:pre"> </span> * @author <a href="mailto:3313971898@qq.com">Jason</a>
<span style="white-space:pre"> </span> * @date 2016年1月21日
<span style="white-space:pre"> </span> * @param sheetName 表名，excel里的sheet表<span style="white-space:pre"> </span>
<span style="white-space:pre"> </span> * @param headers 表头
<span style="white-space:pre"> </span> * @param cols 需要导出的列,对应headers
<span style="white-space:pre"> </span> * @param data 数据集
<span style="white-space:pre"> </span> * @param response
<span style="white-space:pre"> </span> * @throws IOException 
<span style="white-space:pre"> </span> */

</pre><pre name="code" class="java">@SuppressWarnings("rawtypes")
public void write(String outPath,String sheetName,String[] headers,String[] cols,List<Map> data,HttpServletResponse response) throws IOException  {
// 创建工作文档对象
Workbook wb = new HSSFWorkbook();
// 创建sheet对象
Sheet sheet = wb.createSheet(sheetName);
// 循环写入行数据
Row row = sheet.createRow(0);
for (short i = 0; i < headers.length; i++) {
Cell cell = row.createCell(i);
cell.setCellValue(headers[i]);
}
Iterator<Map> it = data.iterator();
int index = 0;
OutputStream stream = null;
BufferedInputStream in = null;
BufferedOutputStream out = null;
File f=null;
try {
while (it.hasNext()) {
index++;
row = sheet.createRow(index);
Map map = (Map) it.next();
Object value=null;
for (short i = 0; i < cols.length; i++) {
if(map.containsKey(cols[i])){
value=map.get(cols[i]);
String textValue = null;

<span style="white-space:pre">				</span>//排除空指针异常，都转化成String转到excel
if(value==null){
textValue="";
}else if (value instanceof Timestamp) {
Timestamp date = (Timestamp) value;
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd");
textValue = sdf1.format(date);
}else if (value instanceof Date) {
Date date = (Date) value;
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd");
textValue = sdf1.format(date);
}else {
textValue=value.toString();
}
Cell cell = row.createCell(i);
cell.setCellValue(textValue);
}else{
value=null;
}
}
}
stream = new FileOutputStream(outPath);
wb.write(stream);
f= new File(outPath);
long fLength=0;
if (f.exists() && f.isFile()){
fLength=f.length();
}
String fileName=outPath.substring(outPath.lastIndexOf("/")+1);
response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("UTF-8");
response.setHeader("Content-Disposition", "attachment; filename="+fileName);
response.setHeader("Content-Length",String.valueOf(fLength));
in = new BufferedInputStream(new FileInputStream(f));
out = new BufferedOutputStream(response.getOutputStream());
byte[] fileData = new byte[1024];
int len = 0;
while (-1 != (len=in.read(fileData, 0, fileData.length))) {
out.write(fileData, 0, len);
}
out.flush();

} catch (IOException e) {
e.printStackTrace();
}finally{
if(stream!=null){
stream.close();
}
if(in!=null){
in.close();
}
if(out!=null){
out.close();
}

System.out.println(f.delete());

}

}

在这里我用了参数List<map>来封装对象，相对来说灵活一点，当然也可用JavaBean来封装对象。