JDBC Example

// // start with: // http://localhost/.../servlet/jdbcexample?query=select+*+from+yourtable // // import javax.servlet.*; import javax.servlet.http.*; import java.io.*; import java.sql.*; public class jdbcexample extends HttpServlet { public boolean POOL=true; // true : with connectionpool false:without // String driver="com.informix.jdbc.IfxDriver"; String driver="sun.jdbc.odbc.JdbcOdbcDriver"; // String url="jdbc:informix-sqli://jaguar2:1525/db:informixserver=server1"; String url="jdbc:odbc:yourOdbcDsn"; String user=""; String password=""; public void init (ServletConfig config) throws ServletException { super.init (config); ServletContext context=config.getServletContext(); ConnectionPoolObject cpo=new ConnectionPoolObject(); cpo.startTimer(); context.setAttribute("currentConnections",cpo); } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("Text/html"); PrintWriter out = response.getWriter(); String query = request.getParameter("query"); // query-string out.println(""); out.println("JDBC Example"); out.println(""); out.println(""); Connection conn = null; ConnectionPoolObject cpo=new ConnectionPoolObject(); try { if (POOL) { ServletContext context=getServletContext(); cpo=(ConnectionPoolObject)context.getAttribute("currentConnections"); conn = cpo.getConnection(driver,url,user,password); } else { Class.forName(driver); conn = DriverManager.getConnection(url,user,password); } Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery(query); ResultSetMetaData md = null; md = rs.getMetaData(); int numCols = md.getColumnCount(); out.println(""); out.println(""); for (int i=1; i<= numCols; i++) { out.println(""); }; out.println(""); while(rs.next()) { out.println(""); for ( int i=0; i < numCols; i++ ){ out.println(""); } out.println(""); } out.println("

"+ md.getColumnLabel(i) + "
" + rs.getString(i+1) + "

"); } catch(SQLException e) { out.println("SQLException: " + e.getMessage() + "
"); while((e = e.getNextException()) != null) out.println(e.getMessage() + "
"); } catch(ClassNotFoundException e) { out.println("ClassNotFoundException: " + e.getMessage() + "
"); } finally { if(conn != null) { try { if (POOL) { // ConnectionPoolObject cpo=new ConnectionPoolObject(); cpo.putConnection(url,user,conn,5*60*1000); // keep open for 5 minutes } else { conn.close(); } } catch (Exception ignored) {} } } out.println(""); out.println(""); } }