poi到出word

public InputStream getWordExpStream(){
ByteArrayInputStream bais = null;
try {
StringBuilder sb = new StringBuilder();
sb.append("<center><table style='border-collapse:collapse;'>");
sb.append("<tr>");
sb.append("<td style='border: solid 1px;width:30px;'>标题：</td>");
sb.append("<td style='border: solid 1px;width:600px;'>"+this.title+"</td>");
sb.append("</tr>");
sb.append("<tr>");
sb.append("<td style='border: solid 1px;width:50px;'>内容：</td>");
sb.append("<td style='border: solid 1px;width:600px;'>"+this.content+"</td>");
sb.append("</tr>");
sb.append("</table></center>");

byte b[] = sb.toString().getBytes();
bais = new ByteArrayInputStream(b);
POIFSFileSystem poifs = new POIFSFileSystem();
DirectoryEntry directory = poifs.getRoot();
DocumentEntry documentEntry = directory.createDocument("WordDocument", bais);
ByteArrayOutputStream os = new ByteArrayOutputStream();
poifs.writeFilesystem(os);
contentDisposition = java.net.URLEncoder.encode(this.content+".doc", "UTF-8");
return new ByteArrayInputStream(os.toByteArray());

} catch (IOException e) {
this.LOG.error(e);
}finally{
try {
bais.close();
} catch (IOException e1) {
throw new RuntimeException(e1);
}
}
return null;
}