jsp:include和@include的区别

灰太狼 2023-10-06 11:55 5阅读 0赞
  1. <jsp:include> :动态包含

1、<jsp:include>包含的是html文件

举例:

DynamicInclude.jsp:

  1. <%@pagecontentType="text/html;charset=gb2312"%>
  2. <html>
  3. <head>
  4. <title>动态包含</title>
  5. </head>
  6. <bodystyle="background-color:lightblue">
  7. <jsp:include page="header.html"flush="true"/><!--动态包含-->
  8. <tableborder="1" align="center">
  9. <tr>
  10. <td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>
  11. </tr>
  12. <tr>
  13. <td>a</td><td>b</td><td>c</td><td>d</td>
  14. </tr>
  15. </table>
  16. </body>
  17. </html>

Header.html :

  1. <h2style="font-family:arial;color:red;font-size:25px;text-align:center">
  2. 动态包含的标题(HTML)
  3. </h2>

运行之后,只生成一个servlet,和上面的代码对应如下:

  1. out.write("\r\n");
  2. out.write("<html>\r\n");
  3. out.write("\t<head>\r\n");
  4. out.write("\t\t<title>动态包含</title>\r\n");
  5. out.write("\t</head>\r\n");
  6. out.write("\t<bodystyle=\"background-color:lightblue\">\r\n");
  7. out.write("\r\n");
  8. out.write("\t\t");
  9. org.apache.jasper.runtime.JspRuntimeLibrary.include(request,response, "header.html", out, true);
  10. out.write("<!--动态包含-->\r\n");
  11. out.write("\r\n");
  12. out.write("\t\t<table border=\"1\"align=\"center\">\r\n");
  13. out.write("\t\t\t<tr>\r\n");
  14. out.write("\t\t\t\t<td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>\r\n");
  15. out.write("\t\t\t</tr>\r\n");
  16. out.write("\t\t\t<tr>\r\n");
  17. out.write("\t\t\t\t<td>a</td><td>b</td><td>c</td><td>d</td>\r\n");
  18. out.write("\t\t\t</tr>\r\n");
  19. out.write("\t\t</table>\r\n");
  20. out.write("\t</body>\r\n");
  21. out.write("</html>");

2、<jsp:include>包含的是jsp文件
举例:
DynamicInclude.jsp:

  1. <%@pagecontentType="text/html;charset=gb2312"%>
  2. <html>
  3. <head>
  4. <title>动态包含</title>
  5. </head>
  6. <bodystyle="background-color:lightblue">
  7. <jsp:include page="header.jsp"flush="true"/><!--动态包含-->
  8. <tableborder="1" align="center">
  9. <tr>
  10. <td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>
  11. </tr>
  12. <tr>
  13. <td>a</td><td>b</td><td>c</td><td>d</td>
  14. </tr>
  15. </table>
  16. </body>
  17. </html>

Header.jsp :

  1. <%@pagecontentType="text/html;charset=gb2312"%>
  2. <html>
  3. <body>
  4. <h2style="font-family:arial;color:red;font-size:25px;text-align:center">
  5. 动态包含的标题(JSP)
  6. </h2>
  7. </body>
  8. </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”%>和完整的和,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:

  1. out.write("\r\n");
  2. out.write("<html>\r\n");
  3. out.write("\t<head>\r\n");
  4. out.write("\t\t<title>动态包含</title>\r\n");
  5. out.write("\t</head>\r\n");
  6. out.write("\t<bodystyle=\"background-color:lightblue\">\r\n");
  7. out.write("\r\n");
  8. out.write("\t\t");
  9. org.apache.jasper.runtime.JspRuntimeLibrary.include(request,response, "header.jsp", out, true);
  10. out.write("<!--动态包含-->\r\n");
  11. out.write("\r\n");
  12. out.write("\t\t<table border=\"1\"align=\"center\">\r\n");
  13. out.write("\t\t\t<tr>\r\n");
  14. out.write("\t\t\t\t<td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>\r\n");
  15. out.write("\t\t\t</tr>\r\n");
  16. out.write("\t\t\t<tr>\r\n");
  17. out.write("\t\t\t\t<td>a</td><td>b</td><td>c</td><td>d</td>\r\n");
  18. out.write("\t\t\t</tr>\r\n");
  19. out.write("\t\t</table>\r\n");
  20. out.write("\t</body>\r\n");
  21. out.write("</html>");

header_jsp.java:

  1. out.write("\r\n");
  2. out.write("<html>\r\n");
  3. out.write("\t<body>\r\n");
  4. out.write("\t\t<h2 style=\"font-family:arial;color:red;font-size:25px;text-align:center\">\r\n");
  5. out.write("\t\t\t动态包含的标题(JSP)\r\n");
  6. out.write("\t\t</h2>\r\n");
  7. out.write("\t</body>\r\n");
  8. out.write("</html>");

%@include%:静态包含
1、%@include%包含的是jsp文件

StaticInclude.jsp:

  1. <%@pagecontentType="text/html;charset=gb2312"%>
  2. <html>
  3. <head>
  4. <title>静态包含</title>
  5. </head>
  6. <bodystyle="background-color:lightblue">
  7. <%@include file="header.jsp"%><!--静态包含-->
  8. <tableborder="1" align="center">
  9. <tr>
  10. <td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>
  11. </tr>
  12. <tr>
  13. <td>a</td><td>b</td><td>c</td><td>d</td>
  14. </tr>
  15. </table>
  16. </body>
  17. </html>

header.jsp:

  1. <%@pagecontentType="text/html;charset=gb2312"%>
  2. <h2style="font-family:arial;color:red;font-size:25px;text-align:center">
  3. 静态包含的标题(JSP)
  4. </h2>

运行之后,只生成一个servlet,和上面的代码对应如下:

  1. out.write("\r\n");
  2. out.write("<html>\r\n");
  3. out.write("\t<head>\r\n");
  4. out.write("\t\t<title>静态包含</title>\r\n");
  5. out.write("\t</head>\r\n");
  6. out.write("\t<body style=\"background-color:lightblue\">\r\n");
  7. out.write("\r\n");
  8. out.write("\t\t");
  9. out.write("\r\n");
  10. out.write("<h2style=\"font-family:arial;color:red;font-size:25px;text-align:center\">\r\n");
  11. out.write("\t静态包含的标题(JSP)\r\n");
  12. out.write("</h2>");
  13. out.write("<!--静态包含-->\r\n");
  14. out.write("\t\t<table border=\"1\"align=\"center\">\r\n");
  15. out.write("\t\t\t<tr>\r\n");
  16. out.write("\t\t\t\t<td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>\r\n");
  17. out.write("\t\t\t</tr>\r\n");
  18. out.write("\t\t\t<tr>\r\n");
  19. out.write("\t\t\t\t<td>a</td><td>b</td><td>c</td><td>d</td>\r\n");
  20. out.write("\t\t\t</tr>\r\n");
  21. out.write("\t\t</table>\r\n");
  22. out.write("\t</body>\r\n");
  23. out.write("</html>");

2、%@include%包含的是html文件。

StaticInclude.jsp:

  1. <%@pagecontentType="text/html;charset=gb2312"%>
  2. <html>
  3. <head>
  4. <title>静态包含</title>
  5. </head>
  6. <bodystyle="background-color:lightblue">
  7. <%@include file="header.html"%><!--静态包含-->
  8. <tableborder="1" align="center">
  9. <tr>
  10. <td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>
  11. </tr>
  12. <tr>
  13. <td>a</td><td>b</td><td>c</td><td>d</td>
  14. </tr>
  15. </table>
  16. </body>
  17. </html>

header.html:

  1. <%@pagecontentType="text/html;charset=gb2312"%>
  2. <h2style="font-family:arial;color:red;font-size:25px;text-align:center">
  3. 静态包含的标题(HTML)
  4. </h2>

运行之后,也是只生成一个servlet,和上面的代码对应如下:

  1. out.write("\r\n");
  2. out.write("<html>\r\n");
  3. out.write("\t<head>\r\n");
  4. out.write("\t\t<title>静态包含</title>\r\n");
  5. out.write("\t</head>\r\n");
  6. out.write("\t<bodystyle=\"background-color:lightblue\">\r\n");
  7. out.write("\r\n");
  8. out.write("\t\t");
  9. out.write("\r\n");
  10. out.write("<h2style=\"font-family:arial;color:red;font-size:25px;text-align:center\">\r\n");
  11. out.write("\t静态包含的标题(HTML)\r\n");
  12. out.write("</h2>");
  13. out.write("<!--静态包含-->\r\n");
  14. out.write("\t\t<table border=\"1\"align=\"center\">\r\n");
  15. out.write("\t\t\t<tr>\r\n");
  16. out.write("\t\t\t\t<td>姓名</td><td>性别</td><td>年龄</td><td>爱好</td>\r\n");
  17. out.write("\t\t\t</tr>\r\n");
  18. out.write("\t\t\t<tr>\r\n");
  19. out.write("\t\t\t\t<td>a</td><td>b</td><td>c</td><td>d</td>\r\n");
  20. out.write("\t\t\t</tr>\r\n");
  21. out.write("\t\t</table>\r\n");
  22. out.write("\t</body>\r\n");
  23. 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。


在jsp中有两种包含,静态包含<%@include file=“xxx.jsp”%>和动态包含,下面说一下它们之间的区别

1、<%@include file=“xxx.jsp”%>为jsp中的编译指令,其文件的包含是发生在jsp向servlet转换的时期,而是jsp中的动作指令,其文件的包含是发生在编译时期,也就是将java文件编译为class文件的时期

2、使用静态包含只会产生一个class文件,而使用动态包含会产生多个class文件

3、使用静态包含,包含页面和被包含页面的request对象为同一对象,因为静态包含只是将被包含的页面的内容复制到包含的页面中去;而动态包含包含页面和被包含页面不是同一个页面,被包含的页面的request对象可以取到的参数范围要相对大些,不仅可以取到传递到包含页面的参数,同样也能取得在包含页面向下传递的参数

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