Re: jdbc servlets and jsp - Mailing list pgsql-jdbc
| From | Nick Fankhauser |
|---|---|
| Subject | Re: jdbc servlets and jsp |
| Date | |
| Msg-id | NEBBLAAHGLEEPCGOBHDGKEEMIFAA.nickf@ontko.com Whole thread Raw |
| In response to | jdbc servlets and jsp (Luke Vanderfluit <luke@chipcity.com.au>) |
| List | pgsql-jdbc |
Luke- Are you getting an error message? Any clues other than "just don't work"? One common problem in moving from interactive java code at the command line to servlets/JSP is that people forget that the tomcat code will execute as the web user (typically www_data in apache installs) This means you have to make sure that this user has access to the database & has the jdbc driver in the classpath, etc... I have a tiny little FAQ for postgresql jdbc & tomcat that addresses two common problems here: http://www.fankhausers.com/tomcat/jdbc/ -Nick > -----Original Message----- > From: pgsql-jdbc-owner@postgresql.org > [mailto:pgsql-jdbc-owner@postgresql.org]On Behalf Of Luke Vanderfluit > Sent: Monday, September 08, 2003 2:52 PM > To: pgsql-jdbc@postgresql.org > Subject: [JDBC] jdbc servlets and jsp > > > Hi, > > I'm having a few probs (fun) getting jdbc to work in servlets and jsp, > tomcat in other words. > > I've successfully got jdbc working with postgresql in a regular java > class. > > I have tried using the same code adapted to a servlet and jsp to get a > database connection happening from there, however no luck, > > Is there anything I need to set up in server.xml or web.xml before it > can work? > > here is my jsp and servlet code: > ################################ > jsp file > -=-=-=-= > <html> > <head> > </head> > <%@ page language="java" import="java.sql.*" %> > <body> > <% > > Class.forName("org.postgresql.Driver"); > Connection myConn=DriverManager.getConnection("jdbc:postgresql:mboard", > "luke", ""); > > %> > </body> > </html> > =-=-=-=-=-=-=-=-=-=-=-=-=-= > servlet code > =-=-=-=-=-=-=-=-=-=-=-=-=-= > import javax.servlet.*; > import javax.servlet.http.*; > import java.io.*; > import java.sql.*; > import java.text.DateFormat; > > /** > * ShowEmployees creates an HTML table containing a list of all > * employees (sorted by last name) and the departments to which > * they belong. > */ > public class ShowEmployees extends HttpServlet > { > Connection dbConn = null; > > /** > * Establishes a connection to the database. > */ > public void init() throws ServletException > { > String jdbcDriver = "org.postgresql.Driver"; > String dbURL = "\"jdbc:postgresql:mboard\", \"luke\", \"\""; > > try > { > Class.forName("org.postgresql.Driver").newInstance(); //load > driver > dbConn = DriverManager.getConnection("jdbc:postgresql:megaboard", > "luke", ""); //connect > } > catch (ClassNotFoundException e) > { > throw new UnavailableException("JDBC driver not found:" + > jdbcDriver); > } > catch (SQLException e) > { > throw new UnavailableException("Unable to connect to: " + > dbURL); > } > catch (Exception e) > { > throw new UnavailableException("Error: " + e); > } > } > > /** > * Displays the employees table. > */ > public void service(HttpServletRequest request, > HttpServletResponse response) throws ServletException, > IOException > { > response.setContentType("text/html"); > > PrintWriter out = response.getWriter(); > > try > { > //join EMPLOYEE and DEPARTMENT tables to get all data > String sql = "select * from message;"; > > Statement stmt = dbConn.createStatement(); > ResultSet rs = stmt.executeQuery(sql); > > out.println("<HTML>"); > out.println("<HEAD><TITLE>Show Employees</TITLE></HEAD>"); > out.println("<BODY>"); > out.println("<TABLE BORDER=\"1\" CELLPADDING=\"3\">"); > out.println("<TR>"); > out.println("<TH>Name</TH>"); > out.println("<TH>Department</TH>"); > out.println("<TH>Phone</TH>"); > out.println("<TH>Email</TH>"); > out.println("<TH>Hire Date</TH>"); > out.println("</TR>"); > > while (rs.next()) > { > out.println("<TR>"); > > out.println("<TD>" + rs.getString("resusername") + "</td>"); > > out.println("</TR>"); > } > > out.println("</TABLE>"); > out.println("</BODY></HTML>"); > > rs.close(); > stmt.close(); > } > catch (SQLException e) > { > out.println("<H2>Database currently unavailable.</H2>"); > } > > out.close(); > } > } > > any help would be greatly appreciated. > thanks, > kind regards > Luke > > -- > > ==================================== > "when my computer smiles, I'm happy" > ===============================.~ ~, > Luke Vanderfluit |'/'] > Mobile: 0421 276 282 \~/` > > > ---------------------------(end of broadcast)--------------------------- > TIP 9: the planner will ignore your desire to choose an index scan if your > joining column's datatypes do not match >
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