I'm using JSP with NetBeans and I'm getting the following error

Question

Note:

C:\Users\Greg\Documents\NetBeansProjects\abalon3\build\generated\src\org\apache\jsp\user2_jsp.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

Code:

<%
  String like=" ";
  Vector<String> vcd = new Vector<String>();
  Vector<String> vbo = new Vector<String>();
  vcd=CheckUser.search_latest_cd();
  int jc=vcd.size();
  vbo=CheckUser.search_latest_books();
  int jb=vbo.size();
  int i=0;

%>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>

<body>

<table border="1" cellspacing="10"
bgcolor=#99FFFF>
<tr>
<th>Author</th>
<th>Title</th>
<th>Summary</th>
<th>Genre</th>
<th>year</th>
<th>Price</th>
<th>ID</th>
</tr>
<%if(vbo.size()>0){for( i=jb;i<jb;i-=7){%>
<tr><td><%out.print(vbo.get(i-6));%></td><td><%out.print(vbo.get(i-5));%></td>
<td><%out.print(vbo.get(i-4));%></td><td><%out.print(vbo.get(i-3));%></td>
<td><%out.print(vbo.get(i-2));%></td><td><%out.print(vbo.get(i-1));%></td>
<td><%out.print(vbo.get(i));}}%></td></tr>
</table>

can anyone tell me where's the problem?

Oh, my eyes. Scriptlet code should not have a place in the world. — duffymo, Feb 16 '11 at 00:58
Please read up-to-date tutorials/books. This is a 90's way of writing JSP/HTML. — BalusC, Feb 16 '11 at 13:22

score 1 · Answer 1 · answered Feb 16 '11 at 01:43

1

Try doing what the message says:

Recompile with -Xlint:unchecked for details.

answered Feb 16 '11 at 01:43

Zian Choy

2,738
4
30
62

he can't. It's a generated source file from a JSP being compiled internally by Tomcat. – jwenting Feb 16 '11 at 12:30

score 1 · Answer 2 · edited May 23 '17 at 12:04

Do vcd=CheckUser.search_latest_cd(); and vbo=CheckUser.search_latest_books(); return Vector<String>?

The cause for unchecked or unsafe operations is generally that the compiler cannot check the generictype. Read here for more detials.

Also, Java Vector is deprecated in the later version of JVM. You should consider using List and ArrayList

Another note, you do not need to create an object which never be used. Here is your code:

Vector<String> vcd = new Vector<String>();
vcd=CheckUser.search_latest_cd();

You can set the object directly to vcd:

Vector<String> vcd = CheckUser.search_latest_cd();

or

Vector<String> vcd = null;
vcd=CheckUser.search_latest_cd();

Creating new Vector object which is never be used is a waste of time.

score 0 · Answer 3 · answered Feb 16 '11 at 12:33

0

And last but not least, what you're seeing is not an error but a warning from the compiler (though some compilers can be set up to handle warnings as errors, this isn't the default behavior of the Sun Java compiler).

answered Feb 16 '11 at 12:33

jwenting

4,890
2
22
28

I'm using JSP with NetBeans and I'm getting the following error

3 Answers3