JDBC using Servlets!!!!!!Hurry up!
Hi,
MySelf Savdeep Vasudeva,Presently I am involved in a project using JDBC-ODBC Bridge in which I want to connect a database table to a HTML Page using Java Servlets.When I fill the form on the HTML Page using numeric data in all my variables,it works quite good and the query is executed.Consequently the data of the person who has filled in the form is displayed.But when I want to change one of the numeric variables(parameter variable) to a String by also making the data type change in my table from numeric to character.The query is not executed at all and It gives the exception message.Kindly help me that how should I make a query in the Java Servlets using the String Variables in the condition.Presently I am only Limited to numeric
variables.Waiting for a quick response from your side.
Regards,
Savdeep Vasudeva.
E-mail: [email protected]
Savdeep,
it would really help, if u posted some part of the erroneous code. anyway, u say u have changed the datatype in ur table to string, but while receiving the parameters, what ru using?
for integers values u would have been using something like: rs.getInt(col index);
whereas to get a string value u have to use:
rs.getString(col index);
are u making this change in ur code???
keep progRamming...
-satyen
Similar Messages
-
Implementing jdbc using jsp and servlets
please give me documnetation and few programs with code .
implementing or using jdbc with servlets and jsp.please give me documnetation and few programs with
code .
implementing or using jdbc with servlets and jsp.Well, which do you want to do? Implement JDBC with servlets and JSP - a tricky job, but there's no technical reason why you couldn't for instance write a class which both extends HttpServlet and implements java.sql.Driver. Wouldn't recommend it, though -
HELP! How te retrieve the last row in MYSQL database using Servlet!
Hi ,
I am new servlets. I am trying to retireve the last row id inserted using the servlet.
Could someone show me a working sample code on how to retrieve the last record inserted?
Thanks
MY CODE
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
public class demo_gr extends HttpServlet {
//***** Servlet access to data base
public void doPost (HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
String url = "jdbc:mysql://sql2.njit.edu/ki3_proj";
String param1 = req.getParameter("param1");
PrintWriter out = resp.getWriter();
resp.setContentType("text/html");
String semail, sfname, slname, rfname, rlname, remail, message;
int cardType;
sfname = req.getParameter("sfname");
slname = req.getParameter("slname");
rfname = req.getParameter("rfname");
rlname = req.getParameter("rlname");
semail = req.getParameter("semail");
remail = req.getParameter("remail");
message = req.getParameter("message");
//cardType = req.getParameter("cardType");
cardType = Integer.parseInt(req.getParameter("cardType"));
out.println(" param1 " + param1 + "\n");
String query = "SELECT * FROM greeting_db "
+ "WHERE id =" + param1 + "";
String query2 ="INSERT INTO greeting_db (sfname, slname ,semail , rfname , rlname , remail , message , cardType ,sentdate ,vieweddate) values('";
query2 = query2 + sfname +"','"+ slname + "','"+ semail + "','"+ rfname + "','"+ rlname + "','"+ remail + "','"+ message + "','"+ cardType + "',NOW(),NOW())";
//out.println(" query2 " + query2 + "\n");
if (semail.equals("") || sfname.equals("") ||
slname.equals("") || rfname.equals("") ||
rlname.equals("") || remail.equals("") ||
message.equals(""))
out.println("<h3> Please Click the back button and fill in <b>all</b> fields</h3>");
out.close();
return;
String title = "Your Card Has Been Sent";
out.println("<BODY>\n" +
"<H1 ALIGN=CENTER>" + title + "</H1>\n" );
out.println("\n" +
"\n" +
" From " + sfname + ", " + slname + "\n <br> To "
+ rfname + ", " + rlname + "\n <br>Receiver Email " + remail + "\n<br> Your Message "
+ message + "\n<br> <br> :");
if (cardType ==1)
out.println("<IMG SRC=/WEB-INF/images/bentley.jpg>");
else if(cardType ==2) {
out.println("<IMG SRC=/WEB-INF/images/Bugatti.jpg>");
else if(cardType ==3) {
out.println(" <IMG SRC=/WEB-INF/images/castle.jpg>");
else if(cardType ==4) {
out.println(" <IMG SRC=/WEB-INF/images/motocross.jpg>");
else if(cardType ==5) {
out.println(" <IMG SRC=/WEB-INF/images/Mustang.jpg>");
else if(cardType ==6) {
out.println("<IMG SRC=/WEB-INF/images/Mustang.jpg>");
out.println("</BODY></HTML>");
try {
Class.forName ("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection
( url, "*****", "******" );
Statement stmt = con.createStatement ();
stmt.execute (query2);
//String query3 = "SELECT LAST_INSERT_ID()";
//ResultSet rs = stmt.executeQuery (query3);
//int questionID = rs.getInt(1);
System.out.println("Total rows:"+questionID);
stmt.close();
con.close();
} // end try
catch (SQLException ex) {
//PrintWriter out = resp.getWriter();
resp.setContentType("text/html");
while (ex != null) {
out.println ("SQL Exception: " + ex.getMessage ());
ex = ex.getNextException ();
} // end while
} // end catch SQLException
catch (java.lang.Exception ex) {
//PrintWriter out = resp.getWriter();
resp.setContentType("text/html");
out.println ("Exception: " + ex.getMessage ());
} // end doGet
private void printResultSet ( HttpServletResponse resp, ResultSet rs )
throws SQLException {
try {
PrintWriter out = resp.getWriter();
out.println("<html>");
out.println("<head><title>jbs jdbc/mysql servlet</title></head>");
out.println("<body>");
out.println("<center><font color=AA0000>");
out.println("<table border='1'>");
int numCols = rs.getMetaData().getColumnCount ();
while ( rs.next() ) {
out.println("<tr>");
for (int i=1; i<=numCols; i++) {
out.print("<td>" + rs.getString(i) + "</td>" );
} // end for
out.println("</tr>");
} // end while
out.println("</table>");
out.println("</font></center>");
out.println("</body>");
out.println("</html>");
out.close();
} // end try
catch ( IOException except) {
} // end catch
} // end returnHTML
} // end jbsJDBCServletI dont know what table names and fields you have but
say you have a table called XYZ which has a primary
key field called keyID.
So in order to get the last row inserted, you could
do something like
Select *
from XYZ
where keyID = (Select MAX(keyID) from XYZ);
Good Luckwhat gubloo said is correct ...But this is all in MS SQL Server I don't know the syntax and key words in MYSQL
This works fine if the emp_id is incremental and of type integer
Query:
select *
from employee e, (select max(emp_id) as emp_id from employee) z
where e.emp_id = z.emp_id
or
select top 1 * from employee order by emp_id descUday -
Servlets/JDBC vs. servlets/EJB performance comparison/benchmark
I have a PHB who believes that EJB has no ___performance___ benefit
against straightforward servlets/JSP/JDBC. Personally, I believe that
using EJB is more scalable instead of using servlets/JDBC with
connection pooling.
However, I am at a lost on how to prove it. There is all the theory, but
I would appreciate it if anyone has benchmarks or comparison of
servlets/JSP/JDBC and servlets/JSP/EJB performance, assuming that they
were tasked to do the same thing ( e.g. performance the same SQL
statement, on the same set of tables, etc. ).
Or some guide on how to setup such a benchmark and prove it internally.
In other words, the PHB needs numbers, showing performance and
scalability. In particular, I would like this to be in WLS 6.0.
Any help appreciated.First off, whether you use servlets + JDBC or servlets + EJB, you'll
most likely spend much of your time in the database.
I would strongly suggest that you avoid the servlets + JDBC
architecture. If you want to do straight JDBC code, then it's
preferable to use a stateless session EJB between the presentation layer
and the persistence layer.
So, you should definitely consider an architecture where you have:
servlets/jsp --> stateless session ejb --> JDBC code
Your servlet / jsp layer handles presentation.
The stateless session EJB layer abstracts the persistence layer and
handles transaction demarcation.
Modularity is important here. There's no reason that your presentation
layer should be concerned with your persistence logic. Your application
might be re-used or later enhanced with an Entity EJB, or JCA Connector,
or a JMS queue providing the persistence layer.
Also, you will usually have web or graphic designers who are modifying
the web pages. Generally, they should not be exposed to transactions
and jdbc code.
We optimize the RMI calls so they are just local method calls. The
stateless session ejb instances are pooled. You won't see much if any
performance overhead.
-- Rob
jms wrote:
>
I have a PHB who believes that EJB has no ___performance___ benefit
against straightforward servlets/JSP/JDBC. Personally, I believe that
using EJB is more scalable instead of using servlets/JDBC with
connection pooling.
However, I am at a lost on how to prove it. There is all the theory, but
I would appreciate it if anyone has benchmarks or comparison of
servlets/JSP/JDBC and servlets/JSP/EJB performance, assuming that they
were tasked to do the same thing ( e.g. performance the same SQL
statement, on the same set of tables, etc. ).
Or some guide on how to setup such a benchmark and prove it internally.
In other words, the PHB needs numbers, showing performance and
scalability. In particular, I would like this to be in WLS 6.0.
Any help appreciated.--
Coming Soon: Building J2EE Applications & BEA WebLogic Server
by Michael Girdley, Rob Woollen, and Sandra Emerson
http://learnweblogic.com -
Accessing postgresql record using servlet
Hello every body,
I am trying to access the postgresql database using servlet. But I found the error of ClassNotFound exception: org.postgresql.Driver. One thing more I am using eclipse ide. I have used the postgresql-8.1-404.jdbc3 driver. And I have set it on class path in eclipse.
package dbservlet.example;
import java.io.*;
import java.sql.*;
import java.text.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class DbServletExample1 extends HttpServlet{
public String getServletInfo() {
return "Servlet connects to PostgreSQL database and displays result of a SELECT";
private Connection dbcon; // Connection for scope of DbServletExample1
public void init(ServletConfig config) throws ServletException { // "init" sets up a database connection
String loginUser = "ali";
String loginPasswd = "ali";
String loginUrl = "jdbc:postgresql://127.0.0.1:5432/ali"; // Load the PostgreSQL driver
try{
Class.forName("org.postgresql.Driver");
dbcon = DriverManager.getConnection(loginUrl, loginUser, loginPasswd);
catch (ClassNotFoundException ex){
System.err.println("ClassNotFoundException: " + ex.getMessage());
throw new ServletException("Class not found Error");
catch (SQLException ex){
System.err.println("SQLException: " + ex.getMessage());
// Use http GET
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {
response.setContentType("text/html"); // Response mime type
PrintWriter out = response.getWriter(); // Output stream to STDOUT
out.println("<HTML><Head><Title>Db Servelt Example</Title></Head>");
out.println("<Body><H1>Example of Servlet with Postgres SQL</H1>");
try { // Declare our statement
Statement statement = dbcon.createStatement();
String query = "SELECT empid, name, dept, "; // Perform the query
query += " jobtitle ";
query += "FROM employee ";
ResultSet rs = statement.executeQuery(query);
out.println("<table border>");
while (rs.next()) { // Iterate through each row of rs
String m_id = rs.getString("empid");
String m_name = rs.getString("name");
String m_dept = rs.getString("dept");
String m_jobtitle = rs.getString("jobtitle");
out.println("<tr>" +
"<td>" + m_id + "</td>" +
"<td>" + m_name + "</td>" +
"<td>" + m_dept +"</td>" +
"<td>" + m_jobtitle + "</td>" +
"</tr>");
out.println("</table></body></html>");
statement.close();
catch(Exception ex){
out.println("<HTML>" +
"<Head><Title>" +
"Bedrock: Error" +
"</Title></Head>\n<Body>" +
"<P>SQL error in doGet: " +
ex.getMessage() + "</P></Body></HTML>");
return;
out.close();
and web.xml file is
<web-app>
<database>
<driver>
<type>org.postgresql.Driver</type>
<url>jdbc:postgresql://127.0.0.1:5432/ali</url>
<user>ali</user>
<password>ali</password>
</driver>
</database>
<servlet>
<servlet-name>DbServletExample1</servlet-name>
<servlet-class>dbservlet.example.DbServletExample1</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>DbServletExample1</servlet-name>
<url-pattern>/db11</url-pattern>
</servlet-mapping>
</web-app>
Thanks in advanceThat web.xml doesn't look right to me.
what's that <database> tag? I would only expect to see a <resource-ref> in the web.xml.
I would not touch the server.xml. Create a context.xml and put it in your META-INF directory. That should look like this:
<?xml version="1.0" encoding="UTF-8"?>
<Context path="/your-path" reloadable="true" crossContext="true">
<Resource name="jdbc/your-jndi"
auth="Container"
type="javax.sql.DataSource"
username="your-username"
password="your-password"
driverClassName="your-driver-class"
url="your-url"
maxActive="10"
maxWait="60000"
removeAbandoned="true"
removeAbandonedTimeout="60000"/>
</Context>% -
How to fetch data from DataBase using Servlet ?
Hi all,
Till now, i was just sending values from web page and receive the data in excel format using servlets.
But, now, i want to fetch data from data base. I will be giving inputs in the web page(for the query)....ON click of submit button,
Servlet should be called.
Depending on the input, query has to be executed, and response should be sent to the user.
How to do it?
Code
import java.text.*;
import java.sql.*;
import java.util.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.OutputStream;
/** Simple servlet that reads three parameters from the html
form
public class Fetchdata extends HttpServlet
String query=new String();
String uid="ashvini";
String pwd="******";
try
Connection con=null;
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
String url = "jdbc:odbc:Testing";
con = DriverManager.getConnection(url, uid, pwd);
Statement s = con.createStatement();
query = "select * from gowri.msllst1";
ResultSet rs = s.executeQuery(query);
public void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException, IOException
response.setContentType("application/vnd.ms-excel");
ServletOutputStream out=response.getOutputStream();
out.println("<HTML>" +"<BODY BGCOLOR=\"#FDF5E6\">\n" +
"<H1 ALIGN=CENTER>" + title + "</H1>\n" +
"<table>" +" <th>ITEM Code</th>");
while(rs.next())
out.println("<tr><td>" rs.getString(1).trim()"</tr></td>");
}//end of while
out.println("</table></BODY></HTML>");
}//end of doGet method
}catch(Exception e)
System.out.println(e);
It is giving error message as:
C:\Program Files\Apache Tomcat 4.0\webapps\general\srvlt>javac Fetchdata.java
Fetchdata.java:17: illegal start of type
try
^
Fetchdata.java:48: <identifier> expected
^
2 errors
Is this format is correct? am i placing this doGet method at the right place? is my program's logic is correct?
Please help me?
Regards
AShviniThere is some mistakes in ur code.....how can try catch exists outside a function???
make use of try catch isde ur doGet method and put
Connection con=null;
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
String url = "jdbc:odbc:Testing";
con = DriverManager.getConnection(url, uid, pwd);
Statement s = con.createStatement();
query = "select * from gowri.msllst1";
ResultSet rs = s.executeQuery(query);
isdie doGet method, for the time being,
i think u get me..
regards
shanu -
PageNotFound when using servlets as clients for EJB
Can anyone help me? I have a container managed EJB. I'm using servlets as my client. I placed my EJB's in a jar file and my servlets and html pages in a WAR file. I deployed them using J2EE's deploytool. I can access my html files but not my servlet files. It always says file not found or a 405 error (resource not allowed) I access my servlet this way...
http://localhost:8000/ReservationContextRoot/ReservationAlias
my web.xml file looks like the following:
<?xml version="1.0" encoding="Cp1252"?>
<!DOCTYPE web-app PUBLIC '-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN' 'http://java.sun.com/j2ee/dtds/web-app_2.2.dtd'>
<web-app>
<display-name>ReservationWAR</display-name>
<description>no description</description>
<servlet> <servlet-name>ReservationServlet</servlet-name>
<display-name>ReservationServlet</display-name>
<description>no description</description>
<servlet-class>ReservationServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ReservationServlet</servlet-name>
<url-pattern>ReservationAlias</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>30</session-timeout>
</session-config>
<resource-ref>
<description>no description</description>
<res-ref-name>jdbc/ReservationDB</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
<ejb-ref> <description>no description</description>
<ejb-ref-name>ejb/Reservation</ejb-ref-name>
<ejb-ref-type>Entity</ejb-ref-type>
<home>ReservationHome</home>
<remote>Reservation</remote>
</ejb-ref>
</web-app>Are you sure your servlet class itself can run without problem? Try debug in the these steps:
1. Change your servlet to simply output some HTML text, so you can be sure tomcat can get to your servlet. If this is OK, it means the servlet itself has problem, probably the EJB stuff.
2. Make sure the EJB container is running.
3. Make your servlet a standalone client (not a servlet) and see if it can run. Pay attention to how you do JNDI lookup of the EJB.
Yi -
Could not connect to database using servlet
Hi,
i'm using oracle 8.1.5.0.0, tomcat 3.2.1, jdk1.2.2 to build an intranet application. I downloaded the classes12.zip and nls_charset12.zip from the oracle web site and install in the oracle\ora81\jdbc\lib directory.
when i tried to run the samples code provided by oracle, the program can run properly. but when i tried to run it in my own program using servlet, i got an error as follow:
java.sql.SQLException IoException:The Network Adapter could not establish a connection.
i have gone through the codes but could not found any errors that I made and now i'm run out of ideas on the error i get.
could someone please help me with this problem?
thank you.
regards,
Josephine
nullNo, the web server requires no configuration. You do need to make sure that the classes12.zip file is in the Tomcat classpath - I believe the Tomcat startup script pulls in all the files in $TOMCAT_HOME/lib, so put the zip file there. I assume you had to change your hostname in the connection URL - what are the connection parameters you used in the Oracle samples? Were these samples Servlets, or command-line programs? Usually when you get the "Network Adapted could not establish a connection" error from the JDBC thin driver, it means that your hostname or port number or SID are wrong,or the database is not up.
John H.
null -
Nullpointerexception when using servlet with Mysql on a cobalt Raq3 Server
I'm a student and i have to use servlets and Mysql to make a Database application. Our school has a Cobalt Raq3 server and has installed Java Dev Kit 1.3a.
First problem they can't tell me their driver manager for Mysql.
Second problem when i try my servlet it gives a NullpointerException
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class Testingo2 extends HttpServlet {
// Hier word een Statement en Connectie object aangemaakt die later zullen worden gebruikt om een database aan te spreken
Statement stm;
Connection con;
// Hier word de servlet geinitialiseerd
public void init() throws ServletException {
try {
// Hier wordt de database driver geladen
Class.forName("org.gjt.mm.mysql.Driver");
/** Hier gaan we gebruik maken van het Connection Object om verbinding te maken met de database CFP door een * jdbc.odbc bridge en dit zonder username en passwoord
con = DriverManager.getConnection("jdbc:mysql://cfp.ehsal.be:3306/cfp","bjorn","disaronno");
// Hier zorgen we ervoor dat als er een zich een fout voordoet dat deze getoond wordt
catch (ClassNotFoundException cnfe ) {
System.out.println(cnfe.toString());
catch (SQLException e) {
System.out.println(e.toString());
// Als de servlet het einde van zijn levenscyclus heeft bereikt gaat het connectie object worden afgesloten
public void destroy() {
try { con.close();}
catch (SQLException e) {}
public void doGet (HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
try {
/** Hier gaat men met het Connectie object een statement aanmaken,welk dan later zal worden gebruikt voor het * uitvoeren van query's
stm = con.createStatement();
/** Hier gaat men de query "selecteer alles van de tabel projecten" uitvoeren op de cfp database dankzij het * statement en connection object. Deze gegevens worden dan opgeslagen in de Resultset rs.
ResultSet rs = stm.executeQuery("SELECT project,land,titel,omschrijving,budget,informatie FROM PROJECTEN ");
/** Hier gaat men informatie, over de gegevens die in de ResultSet rs zijn opgeslagen, opslaan in ResultSetMetaData * meta.
ResultSetMetaData meta = rs.getMetaData();
// Hiergaat men het aantal kolommen van de tabel tellen en opslagen in de Integer kolom
int kolom;
kolom = meta.getColumnCount();
// Hier declareerd men welk soort meta type we naar browser sturen, hier dus HTML tekst
res.setContentType("text/html");
// Hier gaan we een PrintWriter object out aanmaken dat gebruikt zal worden om de html tekst naar de client te sturen
PrintWriter out = res.getWriter();
// De basis html code voor deze pagina
out.println("<HTML >");
out.println("<BODY BGCOLOR =fd8017>");
out.println("<H1> <B><CENTER><FONT COLOR='#00008b'> Overzicht van de projecten </FONT></CENTER></B></H1>");
/** Hier defini�ren we een tabel die van de hoogte en breedte van het scherm volledig gebruik maakt, waarvan de boord * van de tabel een dikte van 1 heeft, de ruimte tussen de cellen in de tabel en tussen de randen van een cel en de * inhoud is gelijk aan 2 (in pixels) en een achtergrondkleur fd8017
out.println("<TABLE HEIGHT='100%' WIDTH='100%' BORDER=1 CELLPADDING = 2 CELLSPACING = 2 BGCOLOR =fd8017>");
// begintag voor een nieuwe rij
out.println("<TR>");
/** Hier creeren we een lus om de kolom hoofden naar de client te sturen. Deze lus begint als j=1 en gaat * door tot j = aantal kolommen en na elke loop wordt j verhoogd met 1. Normaal werden alle kolom hoofden * uit de database opgehaald en afgebeeld, maar vermits MySQL geen kolom hoofden aanvaard waar spaties * inzitten heb ik gekozen om hier de kolom hoofden die uit meer dan 1 woord bestaan op te halen en aan te * passen. Dit voor estetische redenen, voor het functioneren van de servlet heeft dit echter geen belang
for(int j=1;j<=kolom;j++){
if (meta.getColumnName(j).equals("project")) {
out.println("<TH><FONT COLOR='#00008b'> project nr </TH>");
else if (meta.getColumnName(j).equals("budget")) {
out.println("<TH><FONT COLOR='#00008b'> budget (in 1000 �) </TH>");
else if (meta.getColumnName(j).equals("informatie")) {
out.println("<TH><FONT COLOR='#00008b'> meer informatie ? </TH>");
else {
out.println("<TH><FONT COLOR='#00008b'>");
out.println(meta.getColumnName(j)+" ");
out.println("</TH>");
// Hier wordt de tag voor een nieuwe rij afgesloten
out.println("</TR>");
// Hier initialiseren we een Integer en String die later zullen worden gebruikt
int k = 0;
String nummer ="";
// Dit deel van de programma code gaan we uitvoeren zolang er nog een volgende rij in de database bestaat
while (rs.next()) {
// Voor elke nieuwe rij wordt k verhoogd met 1
k =k +1;
// De tag voor een nieuwe rij
out.println("<TR>");
// Dit deel van de code wordt uitgevoerd zolang Integer i kleiner is dan het aantal kolommen
for(int i=1;i <= kolom;i++) {
// Een nieuwe cel waarin de data worden afgebeeld in de kleur #00008b
out.println("<TD ALIGN='left' VALIGN ='top'>");
out.println("<FONT COLOR='#00008b'> ");
/** Hier halen we de kolomnaam op van kolom i en slagen we deze op in de String kolomnaam. Dan gaan we van * deze naam de overtollige spaties (links en rechts van de naam) wegwerken.
String kolomnaam = meta.getColumnName(i);
kolomnaam = kolomnaam.trim();
/** Als de kolomnaam gelijk is aan "project" dan gaan we de data van deze cel opslagen in de String nummer en * deze dan doorsturen naar de client. Anders gaan we voort in onze programma code.
if (kolomnaam.equals("project")) {
nummer = rs.getString(i);
out.println(nummer);
/** Als het vorige niet waar is dan gaan we zien of de kolomnaam gelijk is aan "informatie", als dat zo is * dan gaan we de data van de cel opslaan in de String celwaarde.
else if ( kolomnaam.equals("informatie")) {
String celwaarde = rs.getString(i);
char punt = '.';
char under ='_';
nummer = nummer.replace(punt,under);
/** Als deze String celwaade gelijk is aan "Y" dan gaan we een hyperlink afbeelden die opgebouwd is * uit drie delen : de naam "project", de String nummer (de data uit de cel van project waar het * "." is vervangen door "_" ) en de extensie ".html"
if (celwaarde.equals("Y") ){
out.println("<A HREF=project" + nummer + ".html> Project" +" "+ k +" </A>");
/** Als de celwaarde niet gelijk is aan "Y" dan gaan we gewoon de naam "Project" en de Integer k * afbeelden
else {
out.println("Project" +" " + k);
else {
out.println(rs.getString(i));
out.println("</FONT>");
out.println("</TD>");
out.println("</TR>");
out.println(" </TABLE>");
out.println("</BODY>");
out.println("</HTML>");
// Hier wordt het object Satement afgesloten vermts we het niet meer nodig hebben
stm.close();
// Als er bij het uitvoeren van de programma code een fout zich voordoet dan wordt er een foutmelding weergegeven
catch (SQLException e) {
System.out.println(e.toString());The exception is thrown in the Doget method namely stm = con.createStatement();
But i think that when i run my servlet that the init method is not used. I believe the problem is the access to the database.
Thanks for the answer because i'm beginning to hate the cobalt server at my school -
The following worked on my machine as a java console, but tomcat does not seem to like ir. It excepts on classnotfound
com.mysql.jdbc.Driver
help?
try
Class.forName("com.mysql.jdbc.Driver").newInstance();
catch (Exception e)
System.out.println(e.toString());
// localhost192.168.1.101
Connection conn =
DriverManager.getConnection("jdbc:mysql://localhost:3306?" +
"user=root&password=secret");JDBC on Servlets ...is undesirable for most (professional) projects.
try to keep db access code out of your web app if
possible. It's just good conventionAt best that statement is confusing.
I can only guess that you were suggesting that a database layer should be used rather than putting the JDBC code directly in the servlet code. -
Open Jasper Report in new page using servlet
Guys,
Looks very simple but i am having problem making this process work. I am using 11.1.1.4
This is my use case:
- From a employee page, user clicks on a menu item to open report for current employee. I need to pass appropriate report parameters to servlet and open report into new page.
I can successfully call servlet using commandmenuitem and set request parameters and call servlet from backing bean.... but that doesn't open report in a new page.... any way i can do this?
Another option i tried was that using gomenuitem and setting target=blank but in that case i need to pass the parameter using servlet url which i like to avoid.(in case i need to pass many parameters in future) (also values will be set on page so i need to generate url when then click the menuitem...... so there are some hoops and loops i need to go through) I don't know a way to pass the request parameter using backing bean to servlet... i don't think it is possible.
Those are the two approaches i tried.
If you have any better approach...I would appreciate if you can let me know. (i have searched on internet for two days now.... for the solution)
-R
Edited by: polo on Dec 13, 2011 7:22 AMHi,
Hope following will useful
http://sameh-nassar.blogspot.com/2009/10/using-jasper-reports-with-jdeveloper.html
http://www.gebs.ro/blog/oracle/jasper-reports-in-adf/ -
How to define target window when redirecting within frames using servlet?
Howdy:
Is there a way to define target window when redirecting within frames using servlets?
How to do it in JSP as well?
T.I.A.
Oriental SpiritYour servlet (or JSP) can't decide where it is going to be displayed. The browser has already decided that when it makes the request to your servlet.
-
Using servlet to generate XML file
What I want to do is simple but can't work. Hope you guys can give me a hint.
I succesfully generate XML file in command line using Oracle XML parser and class generator. Then I was trying to do it using servlet. it compiles fine but generate NullPointer exception at the line:
Emp e1= new Emp(); //Emp is the root of XML
I suspect the Emp constructor can't correctly find the globalDTD in its superclass -CGDocument. Please note this only happens in servlet setting, not is command line setting. Any suggestion to get arounf this?
Another unrelated question is that when I create a XML file using the Oracle XML parser, it seems all the elements a file has to be added once, otherwise the compiler will compalain about the missing element. this will be inconvinient when I constructing a big XML file, which I 'd liek to split into small piece and add them up. Maybe there is a good way but I just don't know it.
my email: [email protected]Hi,
I'm running into the same problem deploying the classes generated by the class generator. Code works fine from JDeveloper, but had to put my DTD in the directory where my classes are. Deploying the classes with Apache's JServ gives me a NullPointer exception on the first addNode method. I guess it can't find the DTD. I tried to put the DTD in many locations but this didn't fix the problem. Any suggestions?
Steve,
Did you fix this problem? Thanx!
null -
How do i call the method in a class using servlet
i am doing a project which need to use servlet to call a few methods in a class and display those method on the broswer. i tried to write the servlet myself but there are still some errors .. can anyone help:
The servlet i wrote :
package qm.minipas;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class test extends HttpServlet {
Database database;
/** Initializes the servlet.
public void init(ServletConfig config) throws ServletException {
super.init(config);
database = FlatfileDatabase.getInstance();
/** Destroys the servlet.
public void destroy() {
/** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
* @param request servlet request
* @param response servlet response
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {
response.setContentType("text/html");
java.io.PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet</title>");
out.println("</head>");
out.println("<body>");
out.println("this is my class wossname"+FlatfileDatabase.getInstance()); // this is calling the toString() method in the instance of myJavaClass
out.println("this is my method"+FlatfileDatabase.getAll());
out.println("</body>");
out.println("</html>");
out.close();
/** Handles the HTTP <code>GET</code> method.
* @param request servlet request
* @param response servlet response
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {
processRequest(request, response);
/** Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {
processRequest(request, response);
/** Returns a short description of the servlet.
public String getServletInfo() {
return "Short description";
my methods which i need to call are shown below:
public Collection getAll() {
return Collections.unmodifiableCollection(patientRecords);
public Collection getInpatients() {
Collection selection=new ArrayList();
synchronized(patientRecords) {
for(Iterator i=patientRecords.iterator(); i.hasNext();) {
PatientRecord next=(PatientRecord) i.next();
if(next.isInpatient())
selection.add(next);
return Collections.unmodifiableCollection(selection);
public Collection getByAdmissionDate(Date dateOfAdmission) {
List selection=new ArrayList();
for(Iterator i=patientRecords.iterator(); i.hasNext();) {
PatientRecord next=(PatientRecord) i.next();
if(dateOfAdmission.equals(next.getDateOfAdmission()))
selection.add(next);
return Collections.unmodifiableCollection(selection);
public Collection getByAdmissionDates(Date from,Date to)
throws IllegalArgumentException {
if(to.before(from))
throw new IllegalArgumentException("End date must not be before start date");
List selection=new ArrayList();
for(Iterator i=patientRecords.iterator(); i.hasNext();) {
PatientRecord next=(PatientRecord) i.next();
Date nextAD=next.getDateOfAdmission();
if((nextAD.after(from)||nextAD.equals(from))
&&(nextAD.before(to)||nextAD.equals(to)))
selection.add(next);
return Collections.unmodifiableCollection(selection);
public Collection getByDischargeDates(Date from,Date to)
throws IllegalArgumentException {
if(to.before(from))
throw new IllegalArgumentException("End date must not be before start date");
List selection=new ArrayList();
for(Iterator i=patientRecords.iterator(); i.hasNext();) {
PatientRecord next=(PatientRecord) i.next();
Date nextAD=next.getDateOfDischarge();
if(nextAD==null)
continue;
if((nextAD.after(from)||nextAD.equals(from))
&&(nextAD.before(to)||nextAD.equals(to)))
selection.add(next);
return Collections.unmodifiableCollection(selection);
public Collection getByConsultant(String consultant) {
List selection=new ArrayList();
for(Iterator i=patientRecords.iterator(); i.hasNext();) {
PatientRecord next=(PatientRecord) i.next();
if(consultant.equalsIgnoreCase(next.getConsultant()))
selection.add(next);
return Collections.unmodifiableCollection(selection);
public Collection getByDischargeDate(Date dateOfDischarge) {
List selection=new ArrayList();
for(Iterator i=patientRecords.iterator(); i.hasNext();) {
PatientRecord next=(PatientRecord) i.next();
if(dateOfDischarge.equals(next.getDateOfDischarge()))
selection.add(next);
return Collections.unmodifiableCollection(selection);
public Collection getBySurname(String surname) {
List selection=new ArrayList();
for(Iterator i=patientRecords.iterator(); i.hasNext();) {
PatientRecord next=(PatientRecord) i.next();
if(surname.equalsIgnoreCase(next.getSurname()))
selection.add(next);
return Collections.unmodifiableCollection(selection);
public Collection getByWard(String ward) {
List selection=new ArrayList();
for(Iterator i=patientRecords.iterator(); i.hasNext();) {
PatientRecord next=(PatientRecord) i.next();
if(ward.equalsIgnoreCase(next.getWard()))
selection.add(next);
return Collections.unmodifiableCollection(selection);please provide a detail description of your errors.
-
How to invoke a jsp page from java which does not use Servlets?
Hello,
I am working in Documentum. I am trying to invoke a jsp page from another java page which does not use Servlets.
I tried doing this by just instantiating the java class related to the jsp page from my present java class.In my java class related to the jsp page, I have defined onInit() and onRender() methods.
Now, I am trying to call the jsp page from my present java class by just instantiating the java class related to the jsp page. This throws a java.lang.NullPointerException.
Any comments or suggestions on this.Any help would be appreciated.
Thanks,
Ranjith M.VRanjithM.V wrote:
Hello,
Thanks for the reply. One important thing I forgot to mention. I am also using xml component.And?
As this is the standard way used for coding in Documentum, I do not want to use Beans.Well, JSP's should, in and of themselves, contain no functional code. It should all be only display.
Without that is it not possible?What did I say? I said,
masijade wrote:
It is possible, but I very, very, very, much doubt, that it would be worth the effort.And, if you don't know how, a forum is not truely going to be able to help you implement it (at least not in less than a few years time, at which point it would be outdated).
>
Appreciate your understanding and help.
Thanks,
Ranjith M.V
Maybe you are looking for
-
In a FM 11 book, how can I display filename w/o file location?
In a FrameMaker book, how can I display filename without the file's location on the hard drive? For example, The book would list: "MyFile.fm" instead of C:\windows\documents\Framefiles\XYZ Company\widgets\draft_2013_1111\MyFile.fm If this cannot be
-
Mac mini server problem after restart. Desperate scream out for help
Hi there....after restarting my mac mini server I have a white screen with an apple logo in the middle. Anybody here to find help with?
-
Mouse Pointer Disappearing and reappearing
For the past few days my Mouse Pointer will randomly disappear for unspecified lengths and then reappear. I am using the new Blue Tooth Magic Mouse. It also happens with a wired mouse. I have searched high and low for an answer. I however fall to any
-
If I used external hard disk for back up time machine, is it possible to use that external hard disk to save another else from diffrent computers?
-
If I accidently sync my new iphone 4s to a wrong apple id can i reset it and start over?