个人笔记(并非自己总结,而是从别人的博客上看到的)
<jsp:include> :动态包含
1、<jsp:include>包含的是html文件
举例:
DynamicInclude.jsp:
<%@pagecontentType="text/html;charset=gb2312"%>
<html>
<head>
<title>动态包含</title>
</head>
<bodystyle="background-color:lightblue">
<jsp:include page="header.html"flush="true"/><!--动态包含-->
<tableborder="1" align="center">
<tr>
<td>姓名</td><td>性别</td><td>年龄</td><td>爱好</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">
动态包含的标题(HTML)
</h2>
运行之后,只生成一个servlet,和上面的代码对应如下:
out.write("
");
out.write("<html>
");
out.write(" <head>
");
out.write(" <title>动态包含</title>
");
out.write(" </head>
");
out.write(" <bodystyle="background-color:lightblue">
");
out.write("
");
out.write(" ");
org.apache.jasper.runtime.JspRuntimeLibrary.include(request,response, "header.html", out, true);
out.write("<!--动态包含-->
");
out.write("
");
out.write(" <table border="1"align="center">
");
out.write(" <tr>
");
out.write(" <td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>
");
out.write(" </tr>
");
out.write(" <tr>
");
out.write(" <td>a</td><td>b</td><td>c</td><td>d</td>
");
out.write(" </tr>
");
out.write(" </table>
");
out.write(" </body>
");
out.write("</html>");
2、<jsp:include>包含的是jsp文件
举例:
DynamicInclude.jsp:
<%@pagecontentType="text/html;charset=gb2312"%>
<html>
<head>
<title>动态包含</title>
</head>
<bodystyle="background-color:lightblue">
<jsp:include page="header.jsp"flush="true"/><!--动态包含-->
<tableborder="1" align="center">
<tr>
<td>姓名</td><td>性别</td><td>年龄</td><td>爱好</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">
动态包含的标题(JSP)
</h2>
</body>
</html>
运行之后,生成了两个servlet:DynamicInclude_jsp.Java和header_jsp.java,这也是为什么 Header.jsp中要写上<%@page contentType="text/html;charset=gb2312"%>和完整的<html></html>和<body></body>,而Header.html不用写的原因。因为前者两个.jsp文件是两个相互独立的整体,它们之间的关系是通过request和reponse来发生的,而后者只是简单的嵌套。两个servlet对应的代码如下:
DynamicInclude_jsp.java:
out.write("
");
out.write("<html>
");
out.write(" <head>
");
out.write(" <title>动态包含</title>
");
out.write(" </head>
");
out.write(" <bodystyle="background-color:lightblue">
");
out.write("
");
out.write(" ");
org.apache.jasper.runtime.JspRuntimeLibrary.include(request,response, "header.jsp", out, true);
out.write("<!--动态包含-->
");
out.write("
");
out.write(" <table border="1"align="center">
");
out.write(" <tr>
");
out.write(" <td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>
");
out.write(" </tr>
");
out.write(" <tr>
");
out.write(" <td>a</td><td>b</td><td>c</td><td>d</td>
");
out.write(" </tr>
");
out.write(" </table>
");
out.write(" </body>
");
out.write("</html>");
header_jsp.java:
out.write("
");
out.write("<html>
");
out.write(" <body>
");
out.write(" <h2 style="font-family:arial;color:red;font-size:25px;text-align:center">
");
out.write(" 动态包含的标题(JSP)
");
out.write(" </h2>
");
out.write(" </body>
");
out.write("</html>");
<%@include%>:静态包含
1、<%@include%>包含的是jsp文件
StaticInclude.jsp:
<%@pagecontentType="text/html;charset=gb2312"%>
<html>
<head>
<title>静态包含</title>
</head>
<bodystyle="background-color:lightblue">
<%@include file="header.jsp"%><!--静态包含-->
<tableborder="1" align="center">
<tr>
<td>姓名</td><td>性别</td><td>年龄</td><td>爱好</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">
静态包含的标题(JSP)
</h2>
运行之后,只生成一个servlet,和上面的代码对应如下:
out.write("
");
out.write("<html>
");
out.write(" <head>
");
out.write(" <title>静态包含</title>
");
out.write(" </head>
");
out.write(" <body style="background-color:lightblue">
");
out.write("
");
out.write(" ");
out.write("
");
out.write("<h2style="font-family:arial;color:red;font-size:25px;text-align:center">
");
out.write(" 静态包含的标题(JSP)
");
out.write("</h2>");
out.write("<!--静态包含-->
");
out.write(" <table border="1"align="center">
");
out.write(" <tr>
");
out.write(" <td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>
");
out.write(" </tr>
");
out.write(" <tr>
");
out.write(" <td>a</td><td>b</td><td>c</td><td>d</td>
");
out.write(" </tr>
");
out.write(" </table>
");
out.write(" </body>
");
out.write("</html>");
2、<%@include%>包含的是html文件。
StaticInclude.jsp:
<%@pagecontentType="text/html;charset=gb2312"%> <html> <head> <title>静态包含</title> </head> <bodystyle="background-color:lightblue"> <%@include file="header.html"%><!--静态包含--> <tableborder="1" align="center"> <tr> <td>姓名</td><td>性别</td><td>年龄</td><td>爱好</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">
静态包含的标题(HTML)
</h2>
运行之后,也是只生成一个servlet,和上面的代码对应如下:
out.write("
");
out.write("<html>
");
out.write(" <head>
");
out.write(" <title>静态包含</title>
");
out.write(" </head>
");
out.write(" <bodystyle="background-color:lightblue">
");
out.write("
");
out.write(" ");
out.write("
");
out.write("<h2style="font-family:arial;color:red;font-size:25px;text-align:center">
");
out.write(" 静态包含的标题(HTML)
");
out.write("</h2>");
out.write("<!--静态包含-->
");
out.write(" <table border="1"align="center">
");
out.write(" <tr>
");
out.write(" <td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>
");
out.write(" </tr>
");
out.write(" <tr>
");
out.write(" <td>a</td><td>b</td><td>c</td><td>d</td>
");
out.write(" </tr>
");
out.write(" </table>
");
out.write(" </body>
");
out.write("</html>");
由上可以总结出:
对于静态包含,<%@include%>,中包含的文件,只是简单的嵌入到主文件中,就是在jsp页面转化成Servlet时才嵌入到主文件中,因为运行的结果是只生成了一个Servlet。
而对于动态包含<jsp:incude>,如果被包含文件是动态的,那么就会生成两个Servlet,也就是被包含文件也要经过jsp引擎编译执行生成一个Servlet,两个Servlet通过request和reponse进行通信。如果被包含的文件是静态的,那么这种情况和<%@include>就很相似,只生成了一个Servlet,但是他们之间没有进行简单的嵌入,而依然是通过request和reponse进行的通信。