JSP cyclically outputs all values in the Session

I am a Java cainiao. I recently learned from a Web project. When I modified the pages designed by others, I didn't know what values were in the Session at the beginning, at the end, only the following policy is obtained. All values in the Session are output to the console. The specific method is as follows:
Enumeration e = session. getAttributeNames ();
String temp;
System. out. println ("all attributes and values of the Session are output cyclically below :");
For (; e. hasMoreElements ();){
Temp = (String) e. nextElement ();
System. out. println (temp + "=" + (String) session. getAttribute (temp ));
}
 
Note that not all values in the Session can be converted to strings. Therefore, when the Session attribute value is an object that cannot be converted to a String, an error occurs, in this case, we recommend that you only output the attribute name in the Session and determine which one to call directly in the program. In this case, replace row 6th:
System. out. println (temp );

Author: "Three elder brother's technical path"