Declare the variable OUTSIDE a the get/post method scope, you will then be able to increment it on each call to the servlet. See below: private int counter; private Object lock; public void init() throws ServletException{ //init lock lock = new Object(); // create variable counter = 0; } public void doGet(HttpServletRequest request, HttpServletResponse response) … Read more
You have given no HTML or any script you have tried yourself as such the below should serve as a good template for you to get started. DEMO – Cascading dropdowns, show managers for selected department Assuming the following HTML <div> <div style=”float: left;”> Select Department <br /> <select id=”departments”></select> </div> <div style=”float: left; margin-left: … Read more
You have to address the name Attribute of your input Elements Serverside. So if you would have <input type=”text” name=”username” id=”userelementid”> then you would still use request.getParameter(“username”) 0 solved which should i use in request.getParameter in servlet? [duplicate]
Your query looks like this: “SELECT E.username FROM MyUser E” The E.username part will return a list of username Strings. It should be From MyUser to get MyUser objects. Something like: List<MyUser> p1 =sn.createQuery(“FROM MyUser”).list(); 1 solved java.lang.ClassCastException: java.lang.String cannot be cast to
The service locator pattern can be used for looking up services as described in Core J2EE Patterns. Please notice that this pattern can be considered a bit “outdated” and arguably dependency injection should be preferred in most cases (see here for a more elaborate discussion). solved j2ee pattern for centralizing the process of looking up … Read more
You should get an SMS provider for this. They also provide you with an API for their own service, there is no free “out there” API for this. solved Sms API for java web application? [closed]
The jsondata value is JSON text. It starts with [, which means it’s a JSON array. To process it, you should use a JSON parser. See How to parse JSON in Java. Once you have parsed it, you should have a String[] or a List<String>, with 2 values. Both values start with data:image/jpeg;base64, followed by … Read more
Answer Hashtable.contains() Tests if some key maps into the specified value in this hashtable. So, within your Servlet at this line if(!playerList.contains(playerid)) { you’re actually comparing a key (playerid) with all the values (Player objects) in your Hashtable. Hence, the match is failing every time. Your ServletContext (as well as its listener) works fine since … Read more
Filters help you to intercept the incoming request and response. Request filters can: perform security checks, reformat request headers or bodies, audit or log requests, Response filters can: compress the response stream, append or alter the response stream, create a different response altogether. solved What are the real time usage of Filter concept in Java … Read more
StringWriter sWriter = new StringWriter(); PrintWriter out = new PrintWriter(sWriter); out.println(“Hello World”); response.getWriter().print(sWriter.toString()); This creates a StringWriter that is independent of the response. It creates a String with the content you put in it and then takes that and puts it into PrintWriter of the response. PrintWriter out = response.getWriter(); This just gets the PrintWriter … Read more
You are missing the Project name/context path in your url: http://localhost:8080/ProjectName/sayhello solved HTTP status: 404 – Java Servlet [closed]
Use UTF-8 instead. It’s understood by every self-respected client side and server side operating system platform. It’s also considered the standard character encoding these days. Tomcat still defaults to the old ISO 8859-1 charset as to decoding GET request parameters and to the server platform default encoding as to decoding POST request parameters. To set … Read more
i think you should try this public class EmpBean { public java.util.List dataList(){ ArrayList list=new ArrayList(); try{ Class.forName(“driver”); Connection con = DriverManager.getConnection(“url”, “user”, “pwd”); Statement st=con.createStatement(); System.out.println(“hiiiii”); ResultSet rs=st.executeQuery(“select * from employee”); while(rs.next()){ list.add(rs.getString(“name”)); list.add(rs.getString(“address”)); list.add(rs.getString(“contactNo”)); list.add(rs.getString(“email”)); } System.out.println(rs.getString(“contactNo”)); } catch(Exception e){} return list; } } Assuming this class working fine and it is returning … Read more
Your error is on line 73: birthyear = Integer.parseInt(request.getParameter(“birthyear”)); I’m guessing by your code that the form in the doGet function is the form posting the data you want to store in your database. Your form doesn’t contain a birthyear field. Its absence makes request.getParameter(“birthyear”) return null, which causes a NullPointerException when trying to parse … Read more
MultipartFile’s getInputStream() method returns an InputStream. You don’t have to know what kind of InputStream it returns. As you see, it’s not a FileInputStream, and that should not matter. All you need to do is read from the InputStream returned and write to your file. You read from an InputStream the same way, whatever the … Read more