頁面具體是這樣報錯的

HTTP Status 500 - /inc/common_head.jsp (line: 1, column: 2) Page directive: illegal to have multiple occurrences of contentType with different values (old: text/html;charset=UTF-8, new: text/html; charset=UTF-8)

type Exception report

message /inc/common_head.jsp (line: 1, column: 2) Page directive: illegal to have multiple occurrences of contentType with different values (old: text/html;charset=UTF-8, new: text/html; charset=UTF-8)

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: /inc/common_head.jsp (line: 1, column: 2) Page directive: illegal to have multiple occurrences of contentType with different values (old: text/html;charset=UTF-8, new: text/html; charset=UTF-8)
 

頁面程式碼沒錯，我口頭翻譯了一下illegal to have multiple occurrences of contentType with different values，是包含頁面和被包含頁面的contentType設定不一樣

包含頁面原來的page指令是這樣的

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

被包含頁面原來的page指令是這樣的

<%@ page contentType="text/html; charset=UTF-8"%>

我把被包含頁面，也就是我異常中提示的/inc/common_head.jsp頁面中的page指令重新改成了包含頁面中的page指令，就解決了