Example:
<%!
Integer countSomeUsefulStuff() {
...
new ClassFromDefaultPackage(...); // Error
new com.example.GoodClass(...); // Good
}
%>
<html>
<head>
<title>Hello, JSP!</title>
</head>
</html>
NOTE: Such references will not be resolved during compilation of the JSP because a compiled class for the JSP will be usually placed in non-default package (for example, "org.apache.jsp" in case of Tomcat, "com.ibm._jsp" in case of WebSphere), but importing from the default package is not allowed in Java.