Servlet------>JSP

jsp本质是一个servlet！！！

所以可以在jsp中写java代码，在访问jsp的时候，其实就是响应了一个servlet的请求

附上部分源码：

public void _jspService(final javax.servlet.http.HttpServletRequest request, final javax.servlet.http.HttpServletResponse response)
        throws java.io.IOException, javax.servlet.ServletException {

    final javax.servlet.jsp.PageContext pageContext;
    final javax.servlet.ServletContext application;
    final javax.servlet.ServletConfig config;
    javax.servlet.jsp.JspWriter out = null;
    final java.lang.Object page = this;
    javax.servlet.jsp.JspWriter _jspx_out = null;
    javax.servlet.jsp.PageContext _jspx_page_context = null;


    try {
      response.setContentType("text/html; charset=UTF-8");
      pageContext = _jspxFactory.getPageContext(this, request, response,
      			null, false, 8192, true);
      _jspx_page_context = pageContext;
      application = pageContext.getServletContext();
      config = pageContext.getServletConfig();
      out = pageContext.getOut();
      _jspx_out = out;

      out.write("
");
      out.write("
");

java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy");
request.setAttribute("year", sdf.format(new java.util.Date()));
request.setAttribute("tomcatUrl", "http://tomcat.apache.org/");
request.setAttribute("tomcatDocUrl", "/docs/");
request.setAttribute("tomcatExamplesUrl", "/examples/");

      out.write("
");
      out.write("<!DOCTYPE html>
");
      out.write("<html lang="en">
");
      out.write("    <head>
");
      out.write("        <meta charset="UTF-8" />
");
      out.write("        <title>");
      out.print(request.getServletContext().getServerInfo() );
      out.write("</title>
");
      out.write("        <link href="favicon.ico" rel="icon" type="image/x-icon" />
");
      out.write("        <link href="favicon.ico" rel="shortcut icon" type="image/x-icon" />
");
      out.write("        <link href="tomcat.css" rel="stylesheet" type="text/css" />
");
      out.write("    </head>
");
      out.write("
");
      out.write("    <body>
");
      out.write("        <div id="wrapper">
");
      out.write("            <div id="navigation" class="curved container">
");
      out.write("                <span id="nav-home"><a href="");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${tomcatUrl}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null, false));
      out.write("">Home</a></span>
");
      out.write("</html>
");
    } catch (java.lang.Throwable t) {
      if (!(t instanceof javax.servlet.jsp.SkipPageException)){
        out = _jspx_out;
        if (out != null && out.getBufferSize() != 0)
          try {
            if (response.isCommitted()) {
              out.flush();
            } else {
              out.clearBuffer();
            }
          } catch (java.io.IOException e) {}
        if (_jspx_page_context != null) _jspx_page_context.handlePageException(t);
        else throw new ServletException(t);
      }
    } finally {
      _jspxFactory.releasePageContext(_jspx_page_context);
    }
  }
}

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下面学习jsp的语法：

jsp模版元素--------》html标签，模版元素

jsp脚本表达式--------》用于向浏览器输出数据

<body>
<form action="/day06/DoFormServlet" method="post ">
<%@ page import="java.util.Date"%> 
	<%
	Date date=new Date();
	 String time=date.toLocaleString(); 
	 out.write("out方式输出:"+"<br/>");
	 out.write(time);
	 %>
	<br/>
	<% out.write("<%=方式输出"+"<br/>"); %>
	<%= time%>
</body>