Revanth Sharma

hi,

I have new portal 8.0 theme deployed and when ever I deploy the theme or restart the EAR I see these errors in my logs. Did you find any solution for this ?

I am trying to implement something similar to this. Does this work for xls files and doc files or does it mess the format.

Tim and Leo,

Thanks for the comments. I was unable to fix it and I used the bad practice to create a new connection everytime, but I have to finish my exercise on schedule so skipped using the pooled connections. But, yes I want to get involved to know the industry level practices. Lately I have been looking at setting up the tomcat and subscribing to the user and dev mailing list. Its little tough for me to understand which is quite complex for a newbie like me but I am pretty much interested to build my resume .

Coming to the pooled connection as suggested by Bear, java maintains a PooledConnection class which effectively utilizes the opened connections for various SQL calls instead of closing and opening new connections which can be expensive for a heavily loaded server. Correct me if I am wrong

Let me explain you the directories I have my tomcat and the mysql-connector.jar.

My webapp is in the eclipse workspace which is

c:\Documents And Settings\Administrator\workspace\UserRegistration.

I am not sure if my context.xml docBase is exactly looking at the UserRegistration folder in the workspace. As I have said my mysql-connector.jar is in the tomcat/lib directory.
For my exercise level proj I am working on MySQL but if I am working realtime I am not sure if the organization uses mysql or other databases that are available. So, my question is where exactly should the .jar file be placed if diff webapps use the same database or I might be wrong in the question.

I am really interested to know the realtime scenario.

Thank you very much for the comments.

This is a great opportunity for the people who are giving SCJP exam, I would count myself one among the people. It would be great.. if I win the book and score 100% in the certification exam

Hi,

I have been banging my head passing the variable value from one jsp page to other. I have one task, one page behaves as admin. I have a list of users in the database. in the admin.jsp, if the radio button is selected and the edit button is pressed it has to go to the edit.jsp page where we can edit the fields. I am not sure how to pass the selected radio button variable from admin.jsp to edit.jsp

This is the code i have:
<form action="AdministratorServlet" method="post"> <table> <tr> <td><input type="text" name="searchName" size="40"> </td> <td><input type="Submit" value="Search"> </td> </tr> </table> <br> </form> <table border="1" width="700"> <tr> <td width="100"><b>Select</b></td> <td width="100"><b>Username</b></td> <td width="100"><b>Contact No</b></td> <td width="100"><b>SSN</b></td> <td width="100"><b>Date of Birth</b></td> <td width="100"><b>First Name</b></td> <td width="100"><b>Last Name</b></td> </tr> <% if (request.getAttribute("data") != null) { List<String> data = (List<String>) request.getAttribute("data"); Iterator<String> itr = data.iterator(); int i = 0; while (itr.hasNext()) { %> <tr> <td width="100"><input type="radio" name="radio<%=i%>"></td> <td width="100"><%=itr.next()%></td> <td width="100"><%=itr.next()%></td> <td width="100"><%=itr.next()%></td> <td width="100"><%=itr.next()%></td> <td width="100"><%=itr.next()%></td> <td width="100"><%=itr.next()%></td> </tr> <% } %> </table> <br> <table> <tr> <td><button onClick="window.location='register.jsp'" name="add">Add</button> </td> <form action="edit.jsp" method="post"> <td><input type="submit" value="Edit"> </td> </form> </tr> </table> <% } %>

In the edit.jsp I have the following code.

<% String id[]= new String[10]; for(int i=0;i<10;i++){ id[i]=request.getParameter("radio"+i); out.println(id[i]); } %>

I really need some help how to transfer the variable from one jsp to other.

thanks in advance

Hi,

I have written a servlet code for checking if the username is already exists in the database for registering, however my sql query returns zero rows. I have no idea of what is happening in the query.

try { stmt = conn.prepareStatement("SELECT username FROM employeeinfo WHERE username=?"); stmt.setString(1, username); rs = stmt.executeQuery(); out.println("username: "+username + " Row: " + rs.getRow()); if (rs.getRow() > 0) { request.setAttribute("userExists", rs.getRow()); // Dispatch the request RequestDispatcher dispatcher = request.getRequestDispatcher("register.jsp"); if (dispatcher != null) { dispatcher.forward(request, response); } }else { /*try { String query = "INSERT INTO employeeinfo(username, password, contactno, ssn, dob, fname,lname) VALUES (?,?,?,?,?,?,?)"; stmt = conn.prepareStatement(query); stmt.setString(1, username); stmt.setString(2, password); stmt.setInt(3, contactno); stmt.setInt(4, ssn); stmt.setString(5, dob); stmt.setString(6, fName); stmt.setString(7, lName); i = stmt.executeUpdate(); if (i == 1) { response.sendRedirect("http://localhost:8080/UserRegistration/success.jsp"); } else { out.println("Sorry! Error inserting record"); } // rs = // statement.executeQuery("SELECT * from employeeinfo"); } catch (Exception e) { e.getStackTrace(); }*/ } } catch (SQLException e1) { e1.printStackTrace(); }

rs.getRow() returns value zero though there are 2 records in the database with the username I have given. I wanted to print the sql query to check if the query is working properly, i do not understand how to print the query because of the prepared statement. is there a possible way to print the sql query ?

thanks in advance!!

Yes, I have checked and everything seems right. I can't figure out any error.
Well, this has to be suggested for the tomcat group.

Revanth Sharma wrote:Now, I have a different error,

org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'

I believe Tomcat is not able to recognize the path of the mysql-connector which is in the tomcat/lib/ directory. Do I have to add the path for the driver ? I am confused

Now, I have a different error,

org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'

I believe Tomcat is not able to recognize the path of the mysql-connector which is in the tomcat/lib/ directory. Do I have to add the path for the driver ? I am confused

Thanks Tim..

I think the problem with the jndi error is because of my folders that are placed inappropriately. I am starting the tomcat from eclipse and my workspace is in "My Documents" instead of webapps folder in tomcat.
This following is the code i have put in context.xml
<Context path="/UserRegistration" docBase="UserRegistration" reloadable="true" crossContext="true"> <Resource name="jdbc/TestDB" auth="Container" type="javax.sql.DataSource" maxActive="10" maxIdle="30" maxWait="10000" username="root" password="admin" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost:3306/employeedb"/> </Context>

I would really appreciate if someone can help me getting off this burden. I am still learning stuff, so I have a lot ahead to do !

Thank you. I have read the documentation on connection pooling and also the container-managed pooling on tomcat website. I followed this link
http://tomcat.apache.org/tomcat-6.0-doc/jndi-resources-howto.html

However, the documentation says I can write script in context.xml and I have trouble connecting. I get the error
javax.naming.NameNotFoundException: Name jdbc is not bound in this Context. I am not sure what changes I have to make

Thank you very much Ryan and Bear, I have another question. The connection is successful, how to make the connection persistent or available to other classes. I have another file RegisterServlet which handles user registration. Will I be able to use the same connection I created earlier in other classes ?

I am a newbie, I am learning could you please elaborate on container-oriented connection pooling ?

I know that writing own connection code is a poor practice, those are the basic level examples that I found on roseindia.net/servlets.

Hello,

I am learning Servlets and JSP. I have trouble creating an object for the static factory method I had written for database connection. And I need some suggestions and helpful tips of developing my class in object oriented fashion.

The database connection code I had written:
import java.util.*; import java.sql.*; public class databaseConn { private String url; private Connection conn; public static databaseConn getInstance() { return new databaseConn(); } private databaseConn() { url = "jdbc:mysql://localhost/employeedb?user=root&password=admin"; try { Class.forName("com.mysql.jdbc.Driver"); conn = DriverManager.getConnection(url); conn.createStatement(); } catch(Exception e) { e.printStackTrace(); } } }

I get an error when I call the instance method, and I need some help how after successful connection how do I use this connection to call the SQL query. I have the following code in AuthenticationServlet class which calls the static factory method: I get error at databaseConn dbconn = new databaseConn.getInstance().


import java.io.*; import java.util.*; import javax.servlet.*; import javax.servlet.http.*; import java.sql.*; @SuppressWarnings("serial") public class AuthenticationServlet extends HttpServlet { private ServletConfig config; // Setting JSP page String page = "dataPage.jsp"; public void init(ServletConfig config) throws ServletException { this.config = config; } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); databaseConn dbconn = new databaseConn.getInstance(); ResultSet rs = null; String username = request.getParameter("username"); String password = request.getParameter("password"); PreparedStatement stmt = null; List<String> dataList = new ArrayList<String>(); boolean flag = false; try { stmt = conn.prepareStatement("SELECT name,password,contactno, ssn, dob FROM employeeinfo WHERE name=? AND password=?"); stmt.setString(1, username); stmt.setString(2, password); rs = stmt.executeQuery(); while (rs.next()) { int i = rs.getRow(); request.setAttribute("username", rs.getString("name")); if (i == 1) { dataList.add(rs.getString("name")); dataList.add(rs.getString("contactno")); dataList.add(rs.getString("ssn")); dataList.add(rs.getString("dob")); } else if(i == 0) { flag = false; } flag = true; } } catch(Exception e) { e.printStackTrace(); } if (flag != false) { request.setAttribute("data", dataList); // Dispatch the request RequestDispatcher dispatcher = request.getRequestDispatcher(page); if (dispatcher != null) { dispatcher.forward(request, response); } } else { int statusFlag = 0; request.setAttribute("flag", statusFlag); response.sendRedirect("login.jsp"); } } }


I am not sure where my mistake is, I need some help. Thanks in advance !