<%@include%>和<jsp:include>的區別，發現了一些東西的。
<%@include%>：頁面請求之前預編譯，所有代碼包含進來之後，一起進行處理，把所有代碼合在一起，編譯成一個servlet
<jsp:include>：所有代碼分別處理，在頁面被請求的時候才編譯，被編譯成多個servlet，頁面語法相對獨立，處理完成之後再將代碼的顯示結果（處理結果）組合進來。
JSP中的兩種包含頁面的方法
第一種：include指令：當JSP轉換成Servlet時引入指定文件
<%@ pagecontentType="text/html;charset=GB2312" language="java"errorPage=""%>
<%@ include file="head.jsp"%>
<%@ include file="body.jsp"%>
<%@ include file="tail.jsp"%>
第二種：<jsp:include>動作元素：當JSP頁面被請求時引入指定文件
<%@ page contentType="text/html; charset=GB2312"language="java" errorPage=""%>
<jsp:include page="head.jsp"/>
<jsp:include page="body.jsp"/>
<jsp:include page="tail.jsp"/>
第二種方法可以很方便的用<jsp:param>來向所包含頁傳遞參數，方法如下：
<%@ page contentType="text/html; charset=GB2312"language="java" errorPage=""%>
<jsp:include page="head.jsp"/>
<jsp:includepage="body.jsp">
<jsp:param name="uid"value="username"/>
<jsp:param name="pwd"value="password"/>
</jsp:include>
<jsp:includepage="tail.jsp"/>
<jsp:include> ：動態包含
第一種情況（<jsp:include>包含的是html文件）：
DynamicInclude.jsp:
<%@pagecontentType="text/html;charset=gb2312"%><html> <head> <title>動態包含</title> </head> <bodystyle="background-color:lightblue"> <jsp:include page="header.html"flush="true"/><!--動態包含--> <tableborder="1" align="center"> <tr> <td>姓名</td><td>性別</td><td>年齡</td><td>愛好</td> </tr> <tr> <td>a</td><td>b</td><td>c</td><td>d</td> </tr> </table> </body></html>
Header.html ：
<h2style="font-family:arial;color:red;font-size:25px;text-align:center"> 動態包含的標題(HTML)</h2>
運行之後，只生成一個servlet，和上面的代碼對應如下：
out.write("\r\n");
out.write("<html>\r\n");
out.write("\t<head>\r\n");
out.write("\t\t<title>動態包含</title>\r\n");
out.write("\t</head>\r\n");
out.write("\t<bodystyle=\"background-color:lightblue\">\r\n");
out.write("\r\n");
out.write("\t\t");
<span style="color:#ff0000;">org.apache.jasper.runtime.JspRuntimeLibrary.include(request,response, "header.html", out, true);</span>
out.write("<!--動態包含-->\r\n");
out.write("\r\n");
out.write("\t\t<table border=\"1\"align=\"center\">\r\n");
out.write("\t\t\t<tr>\r\n");
out.write("\t\t\t\t<td>姓名</td><td>性別</td><td>年齡</td><td>愛好</td>\r\n");
out.write("\t\t\t</tr>\r\n");
out.write("\t\t\t<tr>\r\n");
out.write("\t\t\t\t<td>a</td><td>b</td><td>c</td><td>d</td>\r\n");
out.write("\t\t\t</tr>\r\n");
out.write("\t\t</table>\r\n");
out.write("\t</body>\r\n");
out.write("</html>");
第二種情況（<jsp:include>包含的是jsp文件）：
DynamicInclude.jsp:
<%@pagecontentType="text/html;charset=gb2312"%><html> <head> <title>動態包含</title> </head> <bodystyle="background-color:lightblue"> <jsp:include page="header.jsp"flush="true"/><!--動態包含--> <tableborder="1" align="center"> <tr> <td>姓名</td><td>性別</td><td>年齡</td><td>愛好</td> </tr> <tr> <td>a</td><td>b</td><td>c</td><td>d</td> </tr> </table> </body></html>
Header.jsp ：
<%@pagecontentType="text/html;charset=gb2312"%><html> <body> <h2style="font-family:arial;color:red;font-size:25px;text-align:center"> 動態包含的標題(JSP) </h2> </body></html>
運行之後，生成了兩個servlet：DynamicInclude_jsp.java和header_jsp.java，這也是爲什麼 Header.jsp中要寫上<%@page contentType="text/html;charset=gb2312"%>和完整的<html></html>和<body></body>，而Header.html不用寫的原因。因爲前者兩個.jsp文件是兩個相互獨立的整體，它們之間的關係是通過request和reponse來發生的，而後者只是簡單的嵌套。兩個servlet對應的代碼如下：
DynamicInclude_jsp.java：
out.write("\r\n");
out.write("<html>\r\n");
out.write("\t<head>\r\n");
out.write("\t\t<title>動態包含</title>\r\n");
out.write("\t</head>\r\n");
out.write("\t<bodystyle=\"background-color:lightblue\">\r\n");
out.write("\r\n");
out.write("\t\t");
<span style="color:#ff0000;">org.apache.jasper.runtime.JspRuntimeLibrary.include(request,response, "header.jsp", out, true);</span>
out.write("<!--動態包含-->\r\n");
out.write("\r\n");
out.write("\t\t<table border=\"1\"align=\"center\">\r\n");
out.write("\t\t\t<tr>\r\n");
out.write("\t\t\t\t<td>姓名</td><td>性別</td><td>年齡</td><td>愛好</td>\r\n");
out.write("\t\t\t</tr>\r\n");
out.write("\t\t\t<tr>\r\n");
out.write("\t\t\t\t<td>a</td><td>b</td><td>c</td><td>d</td>\r\n");
out.write("\t\t\t</tr>\r\n");
out.write("\t\t</table>\r\n");
out.write("\t</body>\r\n");
out.write("</html>");header_jsp.java:
out.write("\r\n");
out.write("<html>\r\n");
out.write("\t<body>\r\n");
out.write("\t\t<h2 style=\"font-family:arial;color:red;font-size:25px;text-align:center\">\r\n");
out.write("\t\t\t動態包含的標題(JSP)\r\n");
out.write("\t\t</h2>\r\n");
out.write("\t</body>\r\n");
out.write("</html>");
<%@include%>：靜態包含
第一種情況：<%@include%>包含的是jsp文件。
StaticInclude.jsp:
<%@pagecontentType="text/html;charset=gb2312"%><html> <head> <title>靜態包含</title> </head> <bodystyle="background-color:lightblue"> <%@include file="header.jsp"%><!--靜態包含--> <tableborder="1" align="center"> <tr> <td>姓名</td><td>性別</td><td>年齡</td><td>愛好</td> </tr> <tr> <td>a</td><td>b</td><td>c</td><td>d</td> </tr> </table> </body></html>
header.jsp:
<%@pagecontentType="text/html;charset=gb2312"%><h2style="font-family:arial;color:red;font-size:25px;text-align:center"> 靜態包含的標題(JSP)</h2>
運行之後，只生成一個servlet，和上面的代碼對應如下：
out.write("\r\n");
out.write("<html>\r\n");
out.write("\t<head>\r\n");
out.write("\t\t<title>靜態包含</title>\r\n");
out.write("\t</head>\r\n");
out.write("\t<body style=\"background-color:lightblue\">\r\n");
out.write("\r\n");
out.write("\t\t");
out.write("\r\n");
<span style="color:#ff0000;">out.write("<h2style=\"font-family:arial;color:red;font-size:25px;text-align:center\">\r\n");
out.write("\t靜態包含的標題(JSP)\r\n");
out.write("</h2>");</span>
out.write("<!--靜態包含-->\r\n");
out.write("\t\t<table border=\"1\"align=\"center\">\r\n");
out.write("\t\t\t<tr>\r\n");
out.write("\t\t\t\t<td>姓名</td><td>性別</td><td>年齡</td><td>愛好</td>\r\n");
out.write("\t\t\t</tr>\r\n");
out.write("\t\t\t<tr>\r\n");
out.write("\t\t\t\t<td>a</td><td>b</td><td>c</td><td>d</td>\r\n");
out.write("\t\t\t</tr>\r\n");
out.write("\t\t</table>\r\n");
out.write("\t</body>\r\n");
out.write("</html>");
第二種情況：<%@include%>包含的是html文件。
StaticInclude.jsp:
<%@pagecontentType="text/html;charset=gb2312"%><html> <head> <title>靜態包含</title> </head> <bodystyle="background-color:lightblue"> <%@include file="header.html"%><!--靜態包含--> <tableborder="1" align="center"> <tr> <td>姓名</td><td>性別</td><td>年齡</td><td>愛好</td> </tr> <tr> <td>a</td><td>b</td><td>c</td><td>d</td> </tr> </table> </body></html>
header.html:
<%@pagecontentType="text/html;charset=gb2312"%><h2style="font-family:arial;color:red;font-size:25px;text-align:center"> 靜態包含的標題(HTML)</h2>
運行之後，也是隻生成一個servlet，和上面的代碼對應如下：
out.write("\r\n");
out.write("<html>\r\n");
out.write("\t<head>\r\n");
out.write("\t\t<title>靜態包含</title>\r\n");
out.write("\t</head>\r\n");
out.write("\t<bodystyle=\"background-color:lightblue\">\r\n");
out.write("\r\n");
out.write("\t\t");
out.write("\r\n");
<span style="color:#ff0000;">out.write("<h2style=\"font-family:arial;color:red;font-size:25px;text-align:center\">\r\n");
out.write("\t靜態包含的標題(HTML)\r\n");
out.write("</h2>");</span>
out.write("<!--靜態包含-->\r\n");
out.write("\t\t<table border=\"1\"align=\"center\">\r\n");
out.write("\t\t\t<tr>\r\n");
out.write("\t\t\t\t<td>姓名</td><td>性別</td><td>年齡</td><td>愛好</td>\r\n");
out.write("\t\t\t</tr>\r\n");
out.write("\t\t\t<tr>\r\n");
out.write("\t\t\t\t<td>a</td><td>b</td><td>c</td><td>d</td>\r\n");
out.write("\t\t\t</tr>\r\n");
out.write("\t\t</table>\r\n");
out.write("\t</body>\r\n");
out.write("</html>");
由上可以總結出：
對於靜態包含，<%@include%>，中包含的文件，只是簡單的嵌入到主文件中，就是在jsp頁面轉化成Servlet時才嵌入到主文件中，因爲運行的結果是隻生成了一個Servlet。
而對於動態包含<jsp:incude>，如果被包含文件是動態的，那麼就會生成兩個Servlet，也就是被包含文件也要經過jsp引擎編譯執行生成一個Servlet，兩個Servlet通過request和reponse進行通信。如果被包含的文件是靜態的，那麼這種情況和<%@include>就很相似，只生成了一個Servlet，但是他們之間沒有進行簡單的嵌入，而依然是通過request和reponse進行的通信。