Servlet写java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.java的Servlet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Tomcat的webapps目录下,
在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
<%@page import="org.apache.jasper.tagplugins.jstl.core.Out"%>
<%@page 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);
}
}