上传时限制文件类型和文件大小。。。。。。。。
我用servlet来做上传，代码如下：
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType( "text/html;charset=gb2312 ");
HttpSession session = request.getSession();
PrintWriter out = response.getWriter();
String tempfilename = (String) session.getId(); // 会话ID
String path = request.getRealPath( "/ ") + "Accessory/ "; // 取物理路经
File f1 = new File(path, tempfilename); //File对象

int n;
try {
InputStream in = request.getInputStream(); // 取得请求输入流
BufferedInputStream my_in = new BufferedInputStream(in);
FileOutputStream fout = new FileOutputStream(f1);
BufferedOutputStream my_out = new BufferedOutputStream(fout);
byte[] b = new byte[10000];
while ((n = my_in.read(b)) != -1) {
my_out.write(b, 0, n);
}
my_out.flush();
my_out.close();
fout.close();
my_in.close();
in.close();
//读取临时文件f1,从中获取上传文件的名字和上传文件的内容。
RandomAccessFile random1 = new RandomAccessFile(f1, "r ");
random1.readLine();
String filename = random1.readLine();

byte[] b2 = filename.getBytes( "ISO-8859-1 ");
filename = new String(b2);
int pointer = filename.lastIndexOf( '\\ ');
filename = filename.substring(pointer + 1, filename.length() - 1);
File f2 = new File(path, filename);
RandomAccessFile random2 = new RandomAccessFile(f2, "rw ");
random1.seek(0);
for (int i = 1; i <= 4; i++) {
String tempstr = random1.readLine();
}
long startPoint = random1.getFilePointer();
random1.seek(random1.length());
long mark = random1.getFilePointer();
int j = 0;
long endPoint = 0;
while ((mark > = 0) && (j <= 5)) {
mark--;
random1.seek(mark);
n = random1.readByte();
if (n == '\n ') {
j++;
endPoint = random1.getFilePointer();
}
}
long length = endPoint - startPoint + 1;

int order = (int) (length / 10000);
int left = (int) (length % 10000);
byte[] c = new byte[10000];
random1.seek(startPoint);
for (int i = 0; i < order; i++) {
random1.read(c);
random2.write(c);
}
random1.read(c, 0, left);
random2.write(c, 0, left);
random1.close();
random2.close();
f1.delete();

out.print( " <script language= 'javascript '> ");
out.print( "alert( '文件上传成功! '); ");
out.print( "window.location= 'FileUpLoad.jsp '; ");
out.print( " </script> ");

} catch (IOException e) {

e.printStackTrace();
out.print( " <script language= 'javascript '> ");
out.print( "alert( '文件上传失败! '); ");
out.print( "window.location= 'FileUpLoad.jsp '; ");
out.print( " </script> ");
}
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

this.doGet(request, response);
}


要怎么限制文件的类型和大小啊？？

[解决办法]
File f1 = new File(path, tempfilename); //File对象

f1.length()不是可以得到文件的大小吗？
与你规定的大小对比啊，大于规定的，就抛出异常吧。
[解决办法]
filename = new String(b2);
int pointer = filename.lastIndexOf( '\\ ');
filename = filename.substring(pointer + 1, filename.length() - 1);

filename你不也得到了吗，判断一下后缀不就可以限制你要上传的类型了。