There is a jsp page - home.jsp. There are two blocks: one adds the data to the database (it works), and the second gets the data from the database and displays it as a tile (ul -> li). It must receive data upon authorization and after adding new data in the first block.
When I log into my account I wrote this error (redirection works (:
SEVERE: Servlet.service() for servlet [Home] in context with path [/Site] threw exception [An exception occurred processing JSP page /home.jsp at line 70 67: <% 68: ArrayList<Link> links = (ArrayList<Link>)request.getAttribute("links"); 69: 70: for(Link link: links) 71: { 72: System.out.println(link.link.toString()); 73: //out.println(link.link.toString()); Stacktrace:] with root cause java.lang.NullPointerException at org.apache.jsp.home_jsp._jspService(home_jsp.java:199) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Unknown Source) I can't understand why this happens. Checked in the debugger and the data in the ArrayList links is the data in the Link link too.
home.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <% String login = null; Cookie[] cookies = request.getCookies(); for(Cookie cookie: cookies) { //out.println(cookies.length); if(cookie.getName().equals("login")) { login = cookie.getValue(); } } if(login == null) { response.sendRedirect("index"); } request.setAttribute("login", login); %> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>YOUR LINKS - Home</title> <link rel="stylesheet" href="css/normalize.css"> <link rel="stylesheet" href="css/style.css"> <link href='https://fonts.googleapis.com/css?family=Open+Sans&subset=latin,cyrillic,cyrillic-ext' rel='stylesheet' type='text/css'> <link href='https://fonts.googleapis.com/css?family=Source+Sans+Pro:600,700&subset=latin,vietnamese,latin-ext' rel='stylesheet' type='text/css'> <link rel='stylesheet prefetch' href='http://maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css'> </head> <body> <div id="wrapper"> <div id="content"> <%@include file="header.jsp" %> <form action="Logout" method="post"><button type="submit" class="logoutBtn">Logout</button></form> <div class="addLink"> <form action="AddLink" method="post"> <div class="topForm"> <span id="Info"> <% Object infoHome = request.getAttribute("InfoHome"); if (infoHome != null) { out.append(infoHome.toString()); } %> </span> <p class="linkP">Link<span class="req">*</span></p> <input type="text" required placeholder="Paste your link" name="link"/> <p class="titleP" style="width: 4%; margin-left: 35px;">Title</p> <input style="width: 22%;" type="text" placeholder="Title" name="title"/> </div> <p class="descrP">Description</p> <textarea rows="4" cols="10" placeholder="Enter description for a link" name="descr"></textarea> <button type="submit" class="buttonAdd">Add Link</button> </form> </div> <div class="links"> <p>Saved links</p> <div class="bar"> <ul> <%@ page import="java.*" %> <%@ page import="java.util.*" %> <%@ page import="ru.tsyklop.site.Link" %> <% ArrayList<Link> links = (ArrayList<Link>)request.getAttribute("links"); for(Link link: links) { System.out.println(link.link.toString()); //out.println(link.link.toString()); %> <li class="link"><a href="<%= link.link.toString() %>"><%= link.title.toString() %></a></li> <% } %> <%--<c:forEach items="${links}" var="current"> <li class="link"><a href="${current.link}">${current.title}</a></li> </c:forEach> --%> <!--<li class="link"><a>Title</a></li> <li class="link"><a>Title</a></li> <li class="link"><a>Title</a></li> <li class="link"><a>Title</a></li> <li class="link"><a>Title</a></li> <li class="link"><a>Title</a></li> <li class="link"><a>Title</a></li>--> </ul> </div> </div> <%@include file="footer.jsp" %> </div> </div> </body> </html> 