article thumbnail image
Published 2022. 9. 17. 13:28

Spring MVC - EL(Expression Language)

Spring/Ch2. Spring MVC

EL

<%@ page contentType="text/html;charset=utf-8"%>
<%@ taglib prefix="c"   uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%@ page import="com.fastcampus.app.*" %>
<%
	Person person = new Person();
	request.setAttribute("person", person);
	request.setAttribute("name", "kim");   
	request.setAttribute("list", new java.util.ArrayList());	
%>
<html>  
<head>   
	<title>EL</title>   
</head>  
<body>   
person.getCar().getColor()=<%=person.getCar().getColor()%> <br>
person.getCar().getColor()=${person.getCar().getColor()} <br>
person.getCar().getColor()=${person.car.color} <br>    
name=<%=request.getAttribute("name")%> <br>   
name=${requestScope.name} <br>
name=${name} <br>
id=<%=request.getParameter("id")%> <br>
id=${pageContext.request.getParameter("id")} <br>
id=${param.id} <br>
"1"+1 = ${"1"+1} <br>
"1"+="1" = ${"1"+="1"} <br>
"2">1 = ${"2">1} <br>   
null = ${null}<br>
null+1 = ${null+1} <br>
null+null = ${null+null} <br>
"" + null = ${""+null} <br>   
""-1 = ${""-1} <br> 
empty null=${empty null} <br>
empty list=${empty list} <br>
null==0 = ${null==0} <br>
null eq 0 = ${null eq 0} <br>
name == "kim"=${name=="kim"} <br>
name != "kim"=${name!="kim"} <br>
name eq "kim"=${name eq "kim"} <br>  
name ne "kim"=${name ne "kim"} <br>  
name.equals("kim")=${name.equals("kim")} <br>   
</body>
</html>

[실행결과]
person.getCar().getColor()=red
person.getCar().getColor()=red
person.car.color=red
name=kim
name=kim
name=kim
id=asdf
id=asdf
id=asdf
"1"+1 = 2
"1"+="1" = 11
"2">1 = true
null =
null+1 = 1
null+null = 0
"" + null = 0
""-1 = -1
empty null=true
empty list=true
null==0 = false
null eq 0 = false
name == "kim"=true
name != "kim"=false
name eq "kim"=true
name ne "kim"=false
name.equals("kim")=true5

 

jsp 가 서블릿 파일과 클래스 파일로 변환 과정

 

 

C:\sts3\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\work\Catalina\localhost\app\org\apache\jsp

 

 

 

el.jsp.java

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

    if (!javax.servlet.DispatcherType.ERROR.equals(request.getDispatcherType())) {
      final java.lang.String _jspx_method = request.getMethod();
      if ("OPTIONS".equals(_jspx_method)) {
        response.setHeader("Allow","GET, HEAD, POST, OPTIONS");
        return;
      }
      if (!"GET".equals(_jspx_method) && !"POST".equals(_jspx_method) && !"HEAD".equals(_jspx_method)) {
        response.setHeader("Allow","GET, HEAD, POST, OPTIONS");
        response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED, "JSP들은 오직 GET, POST 또는 HEAD 메소드만을 허용합니다. Jasper는 OPTIONS 메소드 또한 허용합니다.");
        return;
      }
    }

    final javax.servlet.jsp.PageContext pageContext;
    javax.servlet.http.HttpSession session = null;
    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, true, 8192, true);
      _jspx_page_context = pageContext;
      application = pageContext.getServletContext();
      config = pageContext.getServletConfig();
      session = pageContext.getSession();
      out = pageContext.getOut();
      _jspx_out = out;

      out.write("\r\n");
      out.write("\r\n");
      out.write("\r\n");
      out.write("\r\n");

	Person person = new Person();
	request.setAttribute("person", person);
	request.setAttribute("name", "kim");   
	request.setAttribute("list", new java.util.ArrayList());	

      out.write("\r\n");
      out.write("<html>  \r\n");
      out.write("<head>   \r\n");
      out.write("	<title>EL</title>   \r\n");
      out.write("</head>  \r\n");
      out.write("<body>   \r\n");
      out.write("person.getCar().getColor()=");
      out.print(person.getCar().getColor());
      out.write(" <br>\r\n");
      out.write("person.getCar().getColor()=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${person.getCar().getColor()}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("person.getCar().getColor()=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${person.car.color}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>    \r\n");
      out.write("name=");
      out.print(request.getAttribute("name"));
      out.write(" <br>   \r\n");
      out.write("name=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${requestScope.name}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("name=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${name}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("id=");
      out.print(request.getParameter("id"));
      out.write(" <br>\r\n");
      out.write("id=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${pageContext.request.getParameter(\"id\")}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("id=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${param.id}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("\"1\"+1 = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${\"1\"+1}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("\"1\"+=\"1\" = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${\"1\"+=\"1\"}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("\"2\">1 = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${\"2\">1}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>   \r\n");
      out.write("null = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${null}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write("<br>\r\n");
      out.write("null+1 = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${null+1}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("null+null = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${null+null}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("\"\" + null = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${\"\"+null}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>   \r\n");
      out.write("\"\"-1 = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${\"\"-1}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br> \r\n");
      out.write("empty null=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${empty null}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("empty list=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${empty list}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("null==0 = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${null==0}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("null eq 0 = ");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${null eq 0}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("name == \"kim\"=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${name==\"kim\"}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("name != \"kim\"=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${name!=\"kim\"}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>\r\n");
      out.write("name eq \"kim\"=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${name eq \"kim\"}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>  \r\n");
      out.write("name ne \"kim\"=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${name ne \"kim\"}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>  \r\n");
      out.write("name.equals(\"kim\")=");
      out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${name.equals(\"kim\")}", java.lang.String.class, (javax.servlet.jsp.PageContext)_jspx_page_context, null));
      out.write(" <br>   \r\n");
      out.write("</body>\r\n");
      out.write("</html>\r\n");
      out.write("\r\n");
      out.write("[실행결과]\r\n");
      out.write("person.getCar().getColor()=red\r\n");
      out.write("person.getCar().getColor()=red\r\n");
      out.write("person.car.color=red\r\n");
      out.write("name=kim\r\n");
      out.write("name=kim\r\n");
      out.write("name=kim\r\n");
      out.write("id=asdf\r\n");
      out.write("id=asdf\r\n");
      out.write("id=asdf\r\n");
      out.write("\"1\"+1 = 2\r\n");
      out.write("\"1\"+=\"1\" = 11\r\n");
      out.write("\"2\">1 = true\r\n");
      out.write("null =\r\n");
      out.write("null+1 = 1\r\n");
      out.write("null+null = 0\r\n");
      out.write("\"\" + null = 0\r\n");
      out.write("\"\"-1 = -1\r\n");
      out.write("empty null=true\r\n");
      out.write("empty list=true\r\n");
      out.write("null==0 = false\r\n");
      out.write("null eq 0 = false\r\n");
      out.write("name == \"kim\"=true\r\n");
      out.write("name != \"kim\"=false\r\n");
      out.write("name eq \"kim\"=true\r\n");
      out.write("name ne \"kim\"=false\r\n");
      out.write("name.equals(\"kim\")=true5");
    } 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);
    }
저작자표시 비영리 변경금지

'Spring > Ch2. Spring MVC' 카테고리의 다른 글

Spring MVC - Filter  (0) 2022.09.17
Spring MVC - JSTL(JSP Standard Tag Library)  (0) 2022.09.17
Spring MVC - 유효 범위(scope)와 속성(attribute)  (0) 2022.09.17
Spring MVC - JSP, Servlet  (0) 2022.09.16
Spring MVC - servlet-context.xml  (0) 2022.09.16
복사했습니다!

티스토리툴바