[javaEE] jsp入门详解编程语言

Servletjava代码很好,但是拼接html的时候,非常不方便

JSP可以在html中嵌套java代码,这样在展示的时候,就会比较方便

 

Tomcat帮我们把jsp的页面翻译成了Servlet去运行的,查看目录

Tomcat目录/work/Catalina/localhost/

生成一个xxx_jsp.javaServlet文件,jsp的脚本片段放在了_jspService()方法里面

 

使用eclipse创建项目以后,修改一下发布路径,直接发布到Tomcatwebapps目录下,

Servers标签栏,先删除下面的项目,在右键点open,选择use Tomcat installation

 

jsp声明:<%! 若干java代码%>,此处的代码会解析到类的成员的地方

jsp注释:<%–注释的内容–%>

index.jsp

<[email protected] import="org.apache.jasper.tagplugins.jstl.core.Out"%> 
<[email protected] import="java.util.Date"%> 
<%@ page language="java" contentType="text/html; charset=utf-8" 
    pageEncoding="utf-8"%> 
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 
<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 
<title>首页</title> 
</head> 
<body> 
<%! 
public void test(){ 
    int a=0; 
} 
%> 
<%  
for(int i=0;i<5;i++){ 
    out.write(i+""); 
} 
%> 
<%--  
Date date=new Date(); 
out.write(date.toLocaleString()); 
--%> 
你好,JSP 
</body> 
</html>

index_jsp.java

public final class index_jsp extends org.apache.jasper.runtime.HttpJspBase 
    implements org.apache.jasper.runtime.JspSourceDependent { 
 
 
public void test(){ 
    int a=0; 
} 
 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; 
    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("<!DOCTYPE html PUBLIC /"-//W3C//DTD HTML 4.01 Transitional//EN/" /"http://www.w3.org/TR/html4/loose.dtd/">/r/n"); 
      out.write("<html>/r/n"); 
      out.write("<head>/r/n"); 
      out.write("<meta http-equiv=/"Content-Type/" content=/"text/html; charset=utf-8/">/r/n"); 
      out.write("<title>首页</title>/r/n"); 
      out.write("</head>/r/n"); 
      out.write("<body>/r/n"); 
      out.write('/r'); 
      out.write('/n'); 
  
for(int i=0;i<5;i++){ 
    out.write(i+""); 
} 
 
      out.write('/r'); 
      out.write('/n'); 
      out.write("/r/n"); 
      out.write("你好,JSP/r/n"); 
      out.write("</body>/r/n"); 
      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); 
    } 
  }

 

 

原创文章,作者:奋斗,如若转载,请注明出处:https://blog.ytso.com/12696.html

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