Java 如何在程序中实现servletcontextlistener?
在我提交作业之前,老师告诉我该项目的一个要求是使用servletcontextlistener。我读了所有关于它的书,但我没有实际的技能来实现它。有人能解释一下我是如何在我的程序中轻松实现这个方法的,它仍然是有用的吗?多谢各位 任务是建立一个网站(前端)并制作一个表单(后端)。这是servlet代码,我认为您不需要查看HTML和JavaScriptJava 如何在程序中实现servletcontextlistener?,java,servlets,Java,Servlets,在我提交作业之前,老师告诉我该项目的一个要求是使用servletcontextlistener。我读了所有关于它的书,但我没有实际的技能来实现它。有人能解释一下我是如何在我的程序中轻松实现这个方法的,它仍然是有用的吗?多谢各位 任务是建立一个网站(前端)并制作一个表单(后端)。这是servlet代码,我认为您不需要查看HTML和JavaScript @WebServlet("/ServletProjekt") public class ServletProjekt ext
@WebServlet("/ServletProjekt")
public class ServletProjekt extends HttpServlet{
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String firstName = request.getParameter("förnamn");
String lastName = request.getParameter("efternamn");
String address = request.getParameter("address");
String email = request.getParameter("email");
String howoften = request.getParameter("howoften");
String newsabout = request.getParameter("news");
String[] age = request.getParameterValues("age");
Cookie firstname = new Cookie ("firstname", firstName);
Cookie lastname = new Cookie ("lastname", lastName);
Cookie Address = new Cookie ("Address", address);
Cookie mail = new Cookie ("mail", email);
Cookie HowOften = new Cookie ("HowOften?", howoften);
Cookie news = new Cookie ("news", newsabout);
firstname.setMaxAge(60 * 60 * 24);
lastname.setMaxAge(60 * 60 * 24);
Address.setMaxAge(60 * 60 * 24);
mail.setMaxAge(60 * 60 * 24);
HowOften.setMaxAge(60 * 60 * 24);
news.setMaxAge(60 * 60 * 24);
response.addCookie(firstname);
response.addCookie(lastname);
response.addCookie(Address);
response.addCookie(mail);
response.addCookie(HowOften);
response.addCookie(news );
response.setContentType("text/html");
PrintWriter printWriter = response.getWriter();
printWriter.write("<html>");
printWriter.write("<h1> THANK YOU FOR YOUR INFORMATION</h1>");
printWriter.write("<body>");
printWriter.write("<p>Your name:</p>" + firstName);
printWriter.write("<br>");
printWriter.write("<p>Your last name:</p>" +lastName + "<br>");
printWriter.write("<p>Your address:</p>" +address + "<br>");
printWriter.write("<p>Your choice of often:</p>" +howoften + "<br>");
printWriter.write("<p>Your choice of news:</p>" +newsabout + "<br>");
printWriter.write("<p>Your email:</p>" +email + "<br>");
for (String ages : age) {
printWriter.write("<p>Your age:</p>" +ages + "<br>");
}
printWriter.write("<a href =\"GetAllCookies\">View All Cookies</a>");
printWriter.write("</body>");
printWriter.write("</html>");
}
}
@WebServlet(“/ServletProjekt”)
公共类ServletProjekt扩展了HttpServlet{
私有静态最终长serialVersionUID=1L;
受保护的void doGet(HttpServletRequest请求,HttpServletResponse响应)抛出ServletException,IOException{
String firstName=request.getParameter(“förnamn”);
字符串lastName=request.getParameter(“efternamn”);
字符串地址=request.getParameter(“地址”);
字符串email=request.getParameter(“email”);
String howfrequency=request.getParameter(“howfrequency”);
字符串newsauto=request.getParameter(“新闻”);
String[]age=request.getParameterValues(“age”);
Cookie firstname=新Cookie(“firstname”,firstname);
Cookie lastname=新Cookie(“lastname”,lastname);
Cookie地址=新Cookie(“地址”,地址);
Cookie mail=新Cookie(“邮件”,电子邮件);
Cookie HowFrequency=新Cookie(“HowFrequency?”,HowFrequency);
Cookie news=新Cookie(“新闻”,newsabout);
firstname.setMaxAge(60*60*24);
lastname.setMaxAge(60*60*24);
地址:setMaxAge(60*60*24);
mail.setMaxAge(60*60*24);
设置最大年龄(60*60*24);
新闻。设置最大年龄(60*60*24);
addCookie(名字);
addCookie(lastname);
addCookie(地址);
addCookie(邮件);
回复:addCookie(多久一次);
回复:addCookie(新闻);
response.setContentType(“text/html”);
PrintWriter PrintWriter=response.getWriter();
printWriter.写(“”);
printWriter.write(“感谢您提供的信息”);
printWriter.写(“”);
printWriter.写(“你的名字:”+名字);
printWriter.write(“
”);
printWriter。写(“你的姓:”+lastName+“
”);
printWriter。写(“你的地址:”+地址+”
”;
printWriter。写(“你选择的频率:”+多久一次+”
”;
printWriter。写(“您选择的新闻:”+newsauton+”
”;
printWriter。写(“你的电子邮件:”+电子邮件+”
”;
用于(字符串年龄:年龄){
printWriter。写(“你的年龄:”+ages+”
”;
}
printWriter.写(“”);
printWriter.写(“”);
printWriter.写(“”);
}
}
实现以下接口:
javax.servlet.ServletContextListener
并在web.xml中包含以下内容(用正确的类名替换类名):
com.something.MyContextListener
首先,您需要这样创建
public class yourServletContextListener
implements ServletContextListener{
@Override
public void contextDestroyed(ServletContextEvent arg0) {
System.out.println("ServletContextListener destroyed");
}
//Run this before web application is started
@Override
public void contextInitialized(ServletContextEvent arg0) {
System.out.println("ServletContextListener started");
}
}
并将其写入web.xml中
<listener>
<listener-class>
fully qualified name for yourServletContextListener
</listener-class>
您的ServletContextListener的完全限定名
同样在Servlet 3.0中,您可以使用来实现侦听器。
<listener>
<listener-class>
fully qualified name for yourServletContextListener
</listener-class>