servlets

问题 This question already has answers here : How to retrieve and display images from a database in a JSP page? (5 answers) Closed 3 years ago . I want to retrieve image from database which is stored as a blob and this image is a profile image of employee so with image some other details will come like name,designation and all so i am passing servlet path and value in employeedetail.jsp and it is going to that servlet and everything is correct like query , parameter but finally on employeedetail

问题 Suppose I want to improve performance by loading whole contents of .css , .js and some other files (favicon, some images) directly from RAM memory without hitting disk. I can just write servlet/controller which will load those files on context init or first request and cache in simple String , but is there any standard already made solution to serve selected static resources from RAM in Spring, Servlets or Tomcat specification? It would be nice to support proper headers also (cache-control

问题 This question already has answers here : Tomcat home page is not showing when running in Eclipse (3 answers) Closed 18 days ago . I have created a Tomcat based web application, as per the instructions given in Learn Java for Web Development (Apress). The web application has been developed as a Dynamic Web Project in Eclipse (exactly as specified in the book). I am using Eclipse version 2019-03 (4.11.0). The complete URL for the application is http://localhost:8080/helloworld/hello . I am able

问题 This question already has answers here : Tomcat home page is not showing when running in Eclipse (3 answers) Closed 18 days ago . I have created a Tomcat based web application, as per the instructions given in Learn Java for Web Development (Apress). The web application has been developed as a Dynamic Web Project in Eclipse (exactly as specified in the book). I am using Eclipse version 2019-03 (4.11.0). The complete URL for the application is http://localhost:8080/helloworld/hello . I am able

问题 I click the download button, and this servlet is called. After calling the image is downloaded, After that when I make the second call, the first image is getting downloaded again. So it keeps on giving me the image which I downloaded first. And not the image for which the mobile number I pass. And here comes my servlet code in doGet: // connects to the database DriverManager.registerDriver(new com.mysql.jdbc.Driver()); conn = DriverManager.getConnection(dbURL, dbUser, dbPass); // queries the

问题 How can I open index.jsp using this url http://localhost:8080/myApp/ and how can I use an hyperlink like this <a href="/">HOME</a> and go to index.jsp ( http://localhost:8080/myApp/ )? Here's my web.xml: <display-name>myApp</display-name> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/application-config.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener>

问题 What happen if I do not specify the contentLenght header when I send a HttpResponse containing a zip file. I did some tests and it seems that the header is set by default with the correct file lenght. Can I be sure that this always happens. When I can found some documentation about? this is the most important part of the code: response.setContentType("application/zip"); response.addHeader("Content-disposition", "attachment; filename=" + zipFileName); zos.close(); out.close(); response

问题 I have a controller servlet which forward the request to the model servlet.Now when the model gets the results from the database, I am forwarding it to the jsp.I am not sure what to write in the jsp because it need to show a table of customerList.here is part of my model servlet: protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Connection connection = getDatabaseConnection(); request.setAttribute("customerList",

问题 I'm tring to upload from my Java local application an object that will include a file to a server. My plan is that a servlet running on tomcat will get the object using the ObjectInputStream in the doGet method. But I get an EOFE xception`. Here is the client code import java.io.*; import java.net.*; public class Client { public static void main(String[] args) throws IOException { FileInputStream inputStream = new FileInputStream("c:\\rafi.txt"); ByteArrayOutputStream output = new

问题 I'm tring to upload from my Java local application an object that will include a file to a server. My plan is that a servlet running on tomcat will get the object using the ObjectInputStream in the doGet method. But I get an EOFE xception`. Here is the client code import java.io.*; import java.net.*; public class Client { public static void main(String[] args) throws IOException { FileInputStream inputStream = new FileInputStream("c:\\rafi.txt"); ByteArrayOutputStream output = new