servlets

javax.persistence.PersistenceException: Invalid persistence.xml

由 ╄→尐↘猪︶ㄣ 提交于 2019-12-30 11:04:42
问题 I'm working on project with Servlet,JPA,EJB and JBoss in eclipse. As you can see in the title of my topic I have an error on my persistence.xml file but I don't know which: <persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"> <persistence-unit name="TrainingAppEJB-PU"> <provider>org.hibernate.ejb

javax.persistence.PersistenceException: Invalid persistence.xml

由 白昼怎懂夜的黑 提交于 2019-12-30 11:03:58
问题 I'm working on project with Servlet,JPA,EJB and JBoss in eclipse. As you can see in the title of my topic I have an error on my persistence.xml file but I don't know which: <persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"> <persistence-unit name="TrainingAppEJB-PU"> <provider>org.hibernate.ejb

Tomcat 7 keeps giving me a 404. What am I doing wrong?

由 陌路散爱 提交于 2019-12-30 10:45:08
问题 this is my first servlet ever. here is it's code. import javax.servlet.*; import javax.servlet.http.*; import java.io.*; public class Ch1Servlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException { PrintWriter out = response.getWriter(); java.util.Date today = new java.util.Date(); out.println("<html> " +"<body>" +"<h1 align=center>HF\'s Chapter1 Servlet</h1>" +" " + "<br>" + today + "</body>" + "</html>"); } } I compiled it

JAVA servlets - open message popup

由 房东的猫 提交于 2019-12-30 10:30:32
问题 I want to user HttpServletResponse object to compose a response that will tell the browser client to open a popup with some message - how can i do that? 回答1: Every Servlet response is basically an Http doc/snippet. So you could return a call to a javascript function that will be executed on the client side. The function can be passed in that Servlet response or it can be pre-included in the .js file. just an example: //servlet code PrintWriter out = response.getWriter(); response

JAVA servlets - open message popup

由 倖福魔咒の 提交于 2019-12-30 10:30:13
问题 I want to user HttpServletResponse object to compose a response that will tell the browser client to open a popup with some message - how can i do that? 回答1: Every Servlet response is basically an Http doc/snippet. So you could return a call to a javascript function that will be executed on the client side. The function can be passed in that Servlet response or it can be pre-included in the .js file. just an example: //servlet code PrintWriter out = response.getWriter(); response

How Tomcat handles multiple requests

由 拜拜、爱过 提交于 2019-12-30 09:58:14
问题 I am aware of creating web application but there is one basic doubt I have. I am sorry for asking very silly question but want to clear my doubt. How Tomcat Container handle request, I mean to say when I send a request for home.jsp page then I get the response as home.jsp page only and not a register.jsp page which at the same time might be the request given by other person requested from other corner of the world. Eg: Client A --------request(a.jsp)----------> Tomcat (check request received

Marking servlet instance variables defined in “init” as “volatile”

由 有些话、适合烂在心里 提交于 2019-12-30 09:51:09
问题 Is it necessary to mark all the servlet instance variables as "volatile" (or to access them from within synchronized sections)? Including those defined in the "init" method, and not modified afterwards? I understand that the "init" method is called by one thread, and the variable will be accessed by another thread, so it seems to be necessary. Or maybe not? Is there any mechanism that guarantees that the current values of instance variables will be visible to all the other threads when the

How to get the anchor name in HTTP GET?

由 懵懂的女人 提交于 2019-12-30 09:46:27
问题 In a Java web project, how can I get (if possible) the "HTTP anchor" part in a URL request? For example, when the request URL is http://localhost:8080/servlet/page.htm?param1=value1&param2=value2#section I want to be able to recognize the #section part. public void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // ... System.out.println("QueryString = " + request.getQueryString()); // ... } The example above produces the substring

How to get the anchor name in HTTP GET?

由 六月ゝ 毕业季﹏ 提交于 2019-12-30 09:46:07
问题 In a Java web project, how can I get (if possible) the "HTTP anchor" part in a URL request? For example, when the request URL is http://localhost:8080/servlet/page.htm?param1=value1&param2=value2#section I want to be able to recognize the #section part. public void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // ... System.out.println("QueryString = " + request.getQueryString()); // ... } The example above produces the substring

config.getInitParameter always return null

由 拈花ヽ惹草 提交于 2019-12-30 09:42:11
问题 Why does config.getInitParameter(String) always return null in the following code example? public void init(ServletConfig config) throws ServletException { super.init(config); filename = config.getInitParameter("addressfile"); This is web.xml file <servlet> <servlet-name>ListManagerServlet</servlet-name> <servlet-class>savva.listmanagerservlet.ListManagerServlet</servlet-class> <init-param> <param-name>addressfile</param-name> <param-value>d:\temp\demo.txt</param-value> </init-param> <
订阅 servlets