servlets

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 7 years ago . I am not sure if this is the correct forum to ask this but i am not sure where to ask either. So here is my question: what does "deep ping" mean. I tried google but still did not get any information about it. Also who does deep ping mean in web servlet`s context. Thanks. 回答1: I'm not sure it's the "official

问题 When I use my search feature, I get an http status 500 error. It claims that Error Report HTTP Status 500 – Internal Server Error Type Exception Report Message SearchServlet has been compiled by a more recent version of the Java Runtime (class file version 53.0), this version of the Java Runtime only recognizes class file versions up to 52.0 (unable to load class [SearchServlet]) Description The server encountered an unexpected condition that prevented it from fulfilling the request.

问题 I searched a lot and can't find an answer. Where the model object values are stored in Spring . Where the model.addAttributes("key","values") values are stored (eg : session , request) .What is the scope of the this? How I can get the values of the stored value in the JSP using the expression language like ${key} ? How the EL works to retrieve the stored values in the model ? 回答1: It's in the request, unless modified with a @SessionAttributes . If you're doing a redirect--request attributes

问题 I am writing a servlet, in that if any exception occurs i donэt want to display exception/error message on browser, so I will redirect to my customized error page. So I have done like this: protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try{ //Here is all code stuff }catch(Exception e){ request.getRequestDispatcher("/ErrorPage.jsp").forward(request, response); e1.printStackTrace(); } Is this the correct way, if I am wrong

问题 I am developing a Dynamic web project. Project is running well on local server but not on live. On live server it throws exception at the line I have used any java object: org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: 7 in the jsp file: /groups.jsp CollectionAppService cannot be resolved to a type 4: <% 5: String json = "[]"; 6: try { 7: CollectionAppService collectionAppService = new CollectionAppService(); 8: json = collectionAppService

问题 I am developing a Dynamic web project. Project is running well on local server but not on live. On live server it throws exception at the line I have used any java object: org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: 7 in the jsp file: /groups.jsp CollectionAppService cannot be resolved to a type 4: <% 5: String json = "[]"; 6: try { 7: CollectionAppService collectionAppService = new CollectionAppService(); 8: json = collectionAppService

问题 Yesterday Tomcat was running ok, but today when I try to run my web-app I get a load of errors and Tomcat does not start. I did not change anything so I have no idea why this is happening. Below is a list of what I am getting. Can you help me resolve this? Using CATALINA_BASE: "C:\apache" Using CATALINA_HOME: "C:\apache" Using CATALINA_TMPDIR: "C:\apache\temp" Using JRE_HOME: "C:\Program Files\Java\jdk1.6.0_29" Using CLASSPATH: "C:\apache\bin\bootstrap.jar;C:\apache\bin\tomcat-juli.jar" 16

问题 I was reading the question "Raw Servlet vs. Spring MVC" and was wondering if Spring MVC might slow down or blow up the memory consumption of your application compared with raw servlet? Note: I originally asked it as a comment in the question mentioned above and was then kindly summoned to post it as a separate question. 回答1: Define "blow up". Define "slow down". Of course memory usage will be higher, and of course performance will be lower. How much higher, and lower compared to the

问题 While working with JSP files and servlets , I came across <% … %> and <%= … %> . What's the difference between both cases ? Thanks 回答1: <%= … %> will echo out a variable, where as <% … %> denotes a script or some code that is executed. Here are the links to the jsp documentation: Expression ( <%= … %> ) : http://java.sun.com/products/jsp/tags/11/syntaxref11.fm4.html Scriptlet ( <% … %> ) : http://java.sun.com/products/jsp/tags/11/syntaxref11.fm5.html 回答2: <%= new java.util.Date() %> is same

问题 I'm new to web development and am just wondering about best practices for java servlets. Should each servlet perform exactly one action, ie a servlet for login, a servlet for registration etc, or should I look to combine similar actions by passing a different parameter to tell the servlet which action to perform? Cheers 回答1: In Frameworks such as Struts there is one single servlet (although there could be multiple instances of it running). This servlet will handle requests for various URLs