2.1 Servlet
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class MyServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
String message = "Hello, World!";
response.getWriter().write(message);
}
}
2.2 JSP
jsp
<html>
<body>
<% String message = "Hello, World!"; %>
<h1><%= message %></h1>
</body>
</html>
2.3 JSTL
jsp
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<html>
<body>
<c:set var="message" value="Hello, World!"/>
<h1><c:out value="${message}"/></h1>
<p>Current Time: <fmt:formatDate value="${now}" pattern="yyyy-MM-dd HH:mm:ss"/></p>
</body>
</html>
<web-app>
<servlet>
<servlet-name>MyServlet</servlet-name>
<servlet-class>com.example.MyServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>MyServlet</servlet-name>
<url-pattern>/hello</url-pattern>
</servlet-mapping>
</web-app>
<context>
<resource-env-ref>
<resource-env-ref-name>jdbc/myDB</resource-env-ref-name>
<resource-env-ref-type>javax.sql.DataSource</resource-env-ref-type>
</resource-env-ref>
</context>
