I am trying to add the form data to the database in java -- using jQuery model form dialog to create a form -- but I cannot see any data in my database.
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class newUserServlet
*/
#WebServlet("/newUserServ")
public class newUserServlet extends HttpServlet {
Connection connection;
#Override
public void init() throws ServletException {
try{
Class.forName("org.gjt.mm.mysql.Driver");
//my database connection url
connection=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","kavuri654");
}catch(Exception e){
e.printStackTrace();
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username =request.getParameter("name");
String email =request.getParameter("email");
String password =request.getParameter("password");
PrintWriter out =response.getWriter();
out.println("<h3>added<h3>");
try{
String selectQuery="insert into test.newuser(name,email,password)"+"values(?,?,?)";
PreparedStatement preparedstatement=connection.prepareStatement(selectQuery);
preparedstatement.setString(1, username);
preparedstatement.setString(2, email);
preparedstatement.setString(3, password);
int i =preparedstatement.executeUpdate();
if(i>0){
System.out.println("one row is added");
}
connection.close();
}catch(Exception e){
e.printStackTrace();
}
}
}
I created a servlet to handle the request sent from the web client. In this servlet, I added the database connection details and I am reading the form data using request object and by using setter methods values are being stored into the database. I am able to add the details to the form but the form data is not stored in database. What should I do to store my form data into the database.
There would be some reasons.
Firstly check if your data "arrive" to this Servlet.
If 1 is ok then you should commit your statement : connection.commit()
Your servlet is ok. First I've created a mysql database test and added the table newuser:
create table newuser (
name varchar(255),
email varchar(255),
password varchar(255)
)
Then I've created a maven jetty project with your code in it. Then I opened following url in the browser:
http://localhost:8899/newUserServ?name=testname&email=testemail&password=testpwd
And voila - the record appeared in the table.
Related
My code to test db connection from eclipse is given below
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;
#WebServlet("/TestDbServlet")
public class TestDbServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String user="user01";
String pass="pass01";
String jdbcUrl = "jdbc:mysql://localhost:3306/web_customer_tracker?useSSL=false&serverTimezone=UTC";
String driver = "com.mysql.cj.jdbc.Driver";
// get connection to database
try {
PrintWriter out = response.getWriter();
out.println("Connecting to database: " + jdbcUrl);
Class.forName(driver);
Connection myConn = DriverManager.getConnection(jdbcUrl, user, pass);
out.println("SUCCESS!!!");
myConn.close();
}
catch (Exception exc) {
exc.printStackTrace();
throw new ServletException(exc);
}
}
am getting 404 error when i run this on server .I have added mysql-connector-java8.0.11.jar to lib folder of webinf.am using tomcat9 with java14 .
Normally, if you are getting a 404 error it means that the page is not found (Probably if your url isn't correct), if there is an error in the doGet Method "The connection to the database part" the server will respond with a 500 error.
https://www.codejava.net/java-ee/servlet/solved-tomcat-error-http-status-404-not-found
Let me know if that helped.
I'm coding for hours to insert data into my SQL database, but nothing happens.
I even can't debug Java, because I don't get any output of my console.
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.PreparedStatement;
import java.text.DecimalFormat;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
*
* #author xxx
*/
public class MyServlet extends HttpServlet {
private static final String URL = "jdbc:mysql://localhost:3306/userdata";
private static final String USER = "root";
private static final String PASSWORD = "root";
private static final DecimalFormat DF2 = new DecimalFormat("#.##");
private static Connection con;
private static Statement stmt;
private static ResultSet rs;
protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
try (PrintWriter out = response.getWriter()) {
try {
String myDriver = "com.mysql.jdbc.Driver";
try {
Class.forName(myDriver);
// opening database connection to MySQL server
con = DriverManager.getConnection(URL, USER, PASSWORD);
// getting Statement object to execute query
// the mysql insert statement
String query = "INSERT INTO customers (customer, currency, amount) values ('Name', 'Currency', 100);";
stmt.executeUpdate(query);
// execute the preparedstatement
// executing SELECT query
rs = stmt.executeQuery(query);
con.close();
stmt.close();
rs.close();
} catch (SQLException sqlEx) {
sqlEx.printStackTrace();
}
}
}
}
What did I wrong, that nothing happens? Even if I use this code for Java-Classes (not Servlets), I only receive an compile error, but without message.
I'm using the IDE Netbeans and mysql DB is the MySQL Workbench. The Java Class is using the main method.
Update:
I've tested following Code with IntelliJ:
import java.sql.*;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Main {
public static void main(String[] args) {
String url = "jdbc:mysql://localhost:3306/userdata";
String user = "root";
String password = "root";
String query = "Insert into customers (customer, currency, amount) values('Michael Ballack', 'Euro', 500)";
try (Connection con = DriverManager.getConnection(url, user, password);
PreparedStatement pst = con.prepareStatement(query)) {
pst.executeUpdate();
} catch (SQLException ex) {
Logger lgr = Logger.getLogger(JdbcMySQLVersion.class.getName());
lgr.log(Level.SEVERE, ex.getMessage(), ex);
}
}
private static class JdbcMySQLVersion {
public JdbcMySQLVersion() {
}
}
I can insert data into the MySQL database.
In Netbeans this code won't work, although I've implemented the MySQLConnector. I don't know why, but Netbeans seems hard to handle.
In the servlet code, I don't see you ever write anything to out. So nothing is being sent back to the browser, even if it compiled. You could write your SQL exception to the out writer you created. To be more precise add this in your exception: out.println(sqlEx.printStackTrace()); That should at least show what exception you are getting back to the browser.
What is the compile error you get outside of a servlet?
This maybe obvious, but to get JDBC stuff to work on your server, you need to have the MySQL server installed, started and configured. The table referenced has to be defined, etc. You could check this outside of the Java servlet environment with the tools provided with MySQL.
your code can not compile, you miss catch exception for second 'try'.
Where do you use this class to run, if you run a java class, this class must contain main() function?
you should use some IDEs like eclipse or IntelliJ to code, it help you detect the error easier.
I found the solution. If you are using Netbeans with the Glassfish-Server and you want your servlet to save data into the database, you have to make sure that Netbeans has installed the Driver of your Database Connector (e.g. MySQL Connector). But you also have to configurate your server (e.g. Glassfish) which will support the DB Connector drivers.
In my case my Server didn't load the DB Connector Driver so the JDBC Code couldn't be executed.
Here's a useful link to configurate the Glassfish Server: https://dzone.com/articles/nb-class-glassfish-mysql-jdbc
This question already has answers here:
ClassNotFoundException: com.mysql.jdbc.Driver. JDBC MySQL driver for web application [duplicate]
(3 answers)
Closed 4 years ago.
I have created a login and registration page but when CREATE ACCOUNT button is clicked the data is not getting stored into the data base. It gives a exception saying
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver"
I have added the mysql jar file in my project.
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
#WebServlet("/loginandregister")
public class loginandregister extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String options=request.getParameter("button");
System.out.println(options);
PrintWriter pw=response.getWriter();
if(options.equals("LOGIN")) {
String username=request.getParameter("loginid");
String password=request.getParameter("loginpassword");
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/loginclass","root","root");
PreparedStatement login=conn.prepareStatement("select * from user_info where username=? and userpassword=?");
login.setString(1, username);
login.setString(2, password);
ResultSet rs=login.executeQuery();
if(rs.next()) {
pw.println("Welcome");
pw.println("Welcome"+username);
}else {
pw.println("Error");
}
}
catch (Exception e) {
e.printStackTrace();
}
}
if(options.equals("CREATE ACCOUNT")) {
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/loginclass","root","root");
PreparedStatement register=conn.prepareStatement("insert into user_info values (?,?,?,?,?,?)");
String firstname=request.getParameter("fname");
String lastname=request.getParameter("lname");
String email=request.getParameter("email");
String phone=request.getParameter("phone");
String uname=request.getParameter("uname");
String pass=request.getParameter("password");
register.setString(1, firstname);
register.setString(2, lastname);
register.setString(3, email);
register.setString(4, phone);
register.setString(5, uname);
register.setString(6, pass);
register.executeUpdate();
}// try
catch (Exception e) {
e.printStackTrace();
}//catch
}// if create acc.
}// dopost
}//class
I think you need to add the jar in your tomcat directory's lib folder. Add the jar there and do a restart of the server.
This might do it for you.
I'm trying to establish a connection from Java to Oracle DB. (My DB is in another machine)
The form of URL as i know is like : String url = "jdbc:oracle:thin:#hostname:portnumber:sid";
And here is my Java code to establish a connection:
package net.metric.action;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class DemoServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text");
PrintWriter out = response.getWriter();
System.out.println("-------- Oracle JDBC Connection Testing ------");
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch (ClassNotFoundException e) {
System.out.println("Where is your Oracle JDBC Driver?");
e.printStackTrace();
return;
}
try{
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
//CONNECT TO DB
String url = "jdbc:oracle:thin:#252.112.60.47:1521:XE";
System.out.println(url);
Connection conn = DriverManager.getConnection(url,"EXT02501231","Tellcom30");
conn.setAutoCommit(false);
Statement stmt = conn.createStatement();
System.out.println("OK");
/* ResultSet rset =
stmt.executeQuery("select * from SBO_AUDIT_NEW.AUDIT_EVENT");
while (rset.next()) {
System.out.println (rset.getString(1));
}
stmt.close();
System.out.println ("Ok.");*/
}catch(Exception e){
System.out.println(e.getMessage());
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
I'm getting this error :
-------- Oracle JDBC Connection Testing ------
Io exception: The Network Adapter could not establish the connection
What am I doing wrong? Any answer would be appreciated..
Thanks
There are three ways to write to a jdbc url.
If you are connecting with service name you should put / before service name
jdbc:oracle:thin:#hostname:port/service_name --- In your case this is how you need the url
if you are connecting with sid you should put : before sid
jdbc:oracle:thin:#hostname:port:sid
or use the description in your tns file after #
jdbc:oracle:thin:#(DESCRIPTION=....)
BUT non of them are the cause for your problem. This error is not an SQLException. It is a TCP/IP connection exception. That means you somehow can not reach the machine.
Are you able to connect to the database with another client ? I see you are using TOAD. Are you able to connect with toad ? You need to make sure you can reach the server.
Try pinging to the machine on command line
ping 85.29.60.47
if you get response back then try telnet on the port
telnet 85.29.60.47 1521 -- You must have a telnet client installed to do that.
You will probably see either ping or telnet fails. So it is probably a firewall issue. What you need to do is to contact network administrators about the problem then.
I'm trying to respond to a get request in java using a database. But it throws some error which I don't know a clue how to fix it.
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TestServlet extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException{
try{
//Accessing driver from the JAR file
Class.forName ("com.mysql.jdbc.Driver").newInstance ();
//Connect to Clockie's database
Connection con = DriverManager.getConnection ("jdbc:mysql://localhost:3306/database", "root", "root");
//Here we create our query
String sql = "" +
"SELECT * " +
"FROM profiles " +
"WHERE profileId = '27'";
PreparedStatement statement = con.prepareStatement(sql);
ResultSet result = statement.executeQuery();
String xmls = "";
result.next();
xmls = result.getString("firstName") + " "+result.getString("lastName");
System.out.println(xmls);
resp.getWriter().println(xmls);
}
catch(Exception e){
System.err.println(e.getMessage());
}
}
}
Everything is fine though, if I set the doGet code block inside the a main method? I'm new to Java pls help!
EDIT:
the exception is "com.mysql.jdbc.Driver";
Print out the full stack trace using e.printStackTrace(); in your catch block.
You may not have the mysql-connector jar which contains com.mysql.jdbc.Driver on your classpath. Check your classpath by printing it out using:
System.out.println("classpath = " + System.getProperty("java.class.path"));