Recently I wrote this code for connecting to MySQL in Eclipse, I am using Java 10 but I run this code I found. I add a sql.connector.jar file also into my class path but still same error:
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
Code:
package ExamplePackage;
import java.sql.*;
import java.util.*;
public class ConnectionManager {
static Connection con;
static String url;
public static Connection getConnection()
{
try
{
String url = "jdbc:mysql://localhost:3306/new_schema.student";
// assuming "DataSource" is your DataSource name
//String connectionUrl = "jdbc:sqlserver://DESKTOP-05S6KIJ;databaseName=users;";
Class.forName("com.mysql.jdbc.Driver");
try
{
con = DriverManager.getConnection(url,"Shaik","Shaik#786");
// assuming your SQL Server's username is "username"
// and password is "password"
}
catch (SQLException ex)
{
ex.printStackTrace();
}
}
catch(Exception e)
{
System.out.println(e);
}
return con;
}
}
I think the issue is not in your project code, you need to add the com.mysql.jdb*.jar driver in your project.
The Class.forName("com.mysql.jdbc.Driver"); is trying to load the driver that is not found -> java.lang.ClassNotFoundException: com.mysql.jdbc.Driver .
Related
As I mentioned on the subject, I am facing the warning "The value of the local variable conn is not used"
I clearly used the variable on my coding but it shows me that type of error.
It will be highly appreciated if you can advise me on this.
[CODE]
package jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class example {
public static void main(String[] ar) {
try {
Class.forName("com.mysql.jdbc.Driver");
System.out.println("Success to find Driver");
}catch(ClassNotFoundException e) {
System.err.println("error = Failed to find driver");
}//*Find MYSQL driver
Connection conn = null;
try {
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/class", "root", "****");
System.out.println("Connected to MySql");
} catch (SQLException e) {
System.err.println("error = Failed to Create connection");
}//* Creating Connection
}
}
[RESULT AFTER RUN]
Success to find Driver
error = Failed to Create connection
In your code you have assigned a reference to conn but you are not using that object anywhere, hence the warning.
To get rid of the warning either use it somewhere (maybe do a sysout somewhere) or add the #SuppressWarnings("unused") annotation
I am writing this because I created a simple Login GUI App to test sqlite database as I am a student of Database Systems and new to it, I used java through eclipse, whenever I run the Application this message
java.sql.SQLException path to c:user//path does not exist
Error Screenshot
I have searched a lot on google but couldn't find the solution there is a similar question on stackoverflow but there were not enough answer related to my problem, I want to know how to change the code to make the Application work and connect to database?
Any help will be much appreciated.Thanks
Here is the code:
package dbms;
import java.sql.*;
import javax.swing.*;
public class dbConnection {
Connection conn = null;
public static Connection dbConnector(){
try{
Class.forName("org.sqlite.JDBC");
Connection conn = DriverManager.getConnection("jdbc:sqlite:C:\\Users\\chusm\\workspace\\DBMS\\SQlite\\DBMS.sqlite");
JOptionPane.showMessageDialog(null, "Connection Successful!!!");
return conn;
}
catch(Exception e){
JOptionPane.showMessageDialog(null, e);
return null;
}
}
}
It looks like you've got some weird whitespace action going on in your url (between "jdbc:sqlite" and "C:"
Please copy paste this exact code in your project and run it (I only removed the weird whitespace, the rest is exactly like your code)
package dbms;
import javax.swing.*;
import java.io.File;
import java.sql.Connection;
import java.sql.DriverManager;
public class StackOverflowExample {
Connection conn = null;
public static Connection dbConnector() {
try {
Class.forName("org.sqlite.JDBC");
Connection conn = DriverManager.getConnection("jdbc:sqlite:C:\\Users\\chusm\\workspace\\DBMS\\SQlite\\DBMS.sqlite");
JOptionPane.showMessageDialog(null, "Connection Successful!!!");
return conn;
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e);
return null;
}
}
public static void main(String[] args) {
Connection connection = dbConnector();
}
}
I am trying to write a java program connecting to a MySQL database. But I am getting this error:
No suitable driver found for jdbc:mysql//localhost:3306/test
I have already installed mysql-connector-java.5.1.23-bin.jar. I am still getting this error.
Here is my program:
package database_practice;
import java.sql.*;
public class CreateConnection {
private Connection conn = null;
public static void main(String args[]) {
CreateConnection conn = new CreateConnection();
conn.getConnection();
}
public Connection getConnection() {
try {
String url = "jdbc:mysql//localhost:3306/test";
String username = "root";
String password = "admin1234";
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = DriverManager.getConnection(url, username, password);
System.out.println("Database Created...!!!");
}
catch (Exception e) {
e.printStackTrace();
System.out.println("Error occured while connecting to database");
}
return conn;
}
}
Your connection string is wrong. This:
"jdbc:mysql//localhost:3306/test"
should be:
"jdbc:mysql://localhost:3306/test"
Note the colon after "mysql".
i am trying to install JDBC but i dont know how, when you only have the jar file, i copied it to my java ext folder but it keep giving me an error, can anyone show me how to complete install the driver and use it?
below is the codes that i used
import java.sql.*;
public class Test1
{
public static void main (String[] args)
{
String url = "jdbc:mysql://localhost:3306/sabayafr_sabmah";
String username = "root";
String password = "ma";
Connection connection = null;
try {
System.out.println("Connecting database...");
connection = DriverManager.getConnection(url, username, password);
System.out.println("Database connected!");
} catch (SQLException e) {
System.err.println("Cannot connect the database!");
e.printStackTrace();
} finally {
System.out.println("Closing the connection.");
if (connection != null) {
try {
connection.close();
} catch (SQLException ignore) {
}
}
}
}
}
And below is the Response that i get
Cannot connect to database server
Update # 3
C:\Users\AlAsad\Desktop>java -cp .;mysql-connector-java-5.0.8-bin.jar Test1
Connecting database...
Cannot connect the database!
java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/
sabayafr_sabmah
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at Test1.main(Test1.java:12)
Closing the connection.
You're trying to connect MySQL with the URL of a jTDS JDBC driver which is designed specifically for Microsoft SQL Server. This ain't ever going to work. Even not when you fix the current problem by placing the JAR file in classpath.
You really need the MySQL JDBC driver. Also see this answer for a short but complete tutorial
On the other hand, if you are using an IDE such as Netbeans or Eclipse you can add the jar file as a resource to the project.
You certainly have JDBC problems, but the exception isn't telling you that. Read it again:
Exception in thread "main" java.lang.NoClassDefFoundError: Test1
Caused by: java.lang.ClassNotFoundException: Test1
It's your Test1.class that it can't find, not the JDBC driver.
You should not be copying anything into the jre/lib/ext directory. That's for library extensions, not JDBC JARs. It wasn't meant as a crutch for people who don't understand how CLASSPATH works.
I'd write it more like the following. Those close methods will come in handy.
When I run it on my machine, adding the MySQL JDBC JAR to my CLASSPATH, I get the following result:
C:\java -classpath .\mysql-connector-java-5.1.6-bin.jar; persistence.utils.DatabaseUtils
product: MySQL
version: 5.1.24-rc-community
major : 5
minor : 1
Here is the source code:
package persistence.utils;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class DatabaseUtils
{
public static final String DRIVER = "com.mysql.jdbc.Driver";
public static final String URL = "jdbc:mysql://localhost:3306/contacts";
public static final String USERNAME = "contacts";
public static final String PASSWORD = "contacts";
public static void main(String[] args)
{
Connection connection = null;
try
{
String driver = ((args.length > 0) ? args[0] : DRIVER);
String url = ((args.length > 1) ? args[1] : URL);
String username = ((args.length > 2) ? args[2] : USERNAME);
String password = ((args.length > 3) ? args[3] : PASSWORD);
connection = getConnection(driver, url, username, password);
DatabaseMetaData metaData = connection.getMetaData();
System.out.println("product: " + metaData.getDatabaseProductName());
System.out.println("version: " + metaData.getDatabaseProductVersion());
System.out.println("major : " + metaData.getDatabaseMajorVersion());
System.out.println("minor : " + metaData.getDatabaseMinorVersion());
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
close(connection);
}
}
public static Connection getConnection(String driver, String url, String username, String password) throws ClassNotFoundException, SQLException
{
Connection connection = null;
Class.forName(driver);
connection = DriverManager.getConnection(url, username, password);
return connection;
}
public static void close(Connection connection)
{
try
{
if (connection != null)
{
connection.close();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static void close(Statement statement)
{
try
{
if (statement != null)
{
statement.close();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static void close(ResultSet resultSet)
{
try
{
if (resultSet != null)
{
resultSet.close();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static void rollback(Connection connection)
{
try
{
if (connection != null)
{
connection.rollback();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
}
'I am trying to install JDBC'
You don't have to install JDBC. It is part of the JDK & JRE.
Try putting your .jar file in the classpath.
The library that contains the Driver (net.sourceforge.jtds.jdbc.Driver) needs to be on the classpath.
Assuming you start your application with
java Test1
then simply do
java -cp .;driver.jar Test1
where 'driver.jar' should be exchanged with the filename (relative or full path) of your database driver lib.
EDIT
A classpath tutorial will exceed the comments section below this question. Please take a cup of coffee and look at this page. It will most likely help you to continue.
I am really new to JAVA but need to call a SQL Server function which I have been given access to.
I have built a JAVA call into a pl/sql function and am successfully calling it from one of my environments. When I move to another environment I get the error
ORA-29532: Java call terminated by uncaught Java exception: java.lang.ClassNotFoundException: com/microsoft/sqlserver/jdbc/SQLServerDriver
I have researched this to death and checked the correct installation of JAVA which seems fine but I'm obviously missing something. I need to somehow trace what is different on this environment, the fact that it runs in the other envionmnet proves that the class is correct so it has to be a config issue.
JAVA Class
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.net.Socket;
import java.io.IOException;
public class xxiceHJ
{
protected static String JDBC_DRIVER = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
protected static String DB_URL = "jdbc:sqlserver://999.999.99.99:1433";
protected static String USER = "xxxx";
protected static String PWD = "xxxxx123$";
public static String getOrderStatus (String OrderNumber) throws SQLException, Exception
{
Connection conn = null;
CallableStatement cs = null;
ResultSet rs = null;
String Message = null;
String WarehouseId = "01";
try
{
// Register JDBC driver
Class.forName(JDBC_DRIVER);
//Open a connection
conn = DriverManager.getConnection(DB_URL, USER, PWD);
cs = conn.prepareCall("{call usp_get_order_status(?,?,?)}");
cs.setString(1, WarehouseId);
cs.setString(2, OrderNumber);
cs.setString(3, Message);
rs = cs.executeQuery();
//if prodeure return a value
if (rs.next())
{
Message = rs.getString(1);
}
//Clean-up environment
rs.close();
cs.close();
conn.close();
// }
// catch (SQLException se)
// {
// //Handle errors for JDBC
// cfFileNumber = "SQLException" + se.toString();
// se.printStackTrace();
// }
// catch (Exception e)
// {
// //Handle errors for Class.forName
// cfFileNumber = "Exception" + e.toString();
// e.printStackTrace();
}
finally
{
//finally block used to close resources
try
{
if (rs!=null)
{
rs.close();
}
}
catch (SQLException se2)
{
//nothing we can do
}
try
{
if (cs!=null)
{
cs.close();
}
}
catch (SQLException se2)
{
//nothing we can do
}
try
{
if (conn!=null)
{
conn.close();
}
}
catch (SQLException se)
{
se.printStackTrace();
}
}
return Message;
}
}
The CLASSPATH variable is the search string that Java Virtual Machine (JVM) uses to locate the JDBC drivers on your computer. If the drivers are not listed in your CLASSPATH variable, you receive the following error message when you try to load the driver:
java.lang.ClassNotFoundException: com/microsoft/jdbc/sqlserver/SQLServerDriver
The JDBC driver is not part of the Java SDK. If you want to use it, you must set the classpath to include the sqljdbc.jar file or the sqljdbc4.jar file. If the classpath is missing an entry for sqljdbc.jar or sqljdbc4.jar, your application will throw the common "Class not found" exception.
The sqljdbc.jar file and sqljdbc4.jar file are installed in the following location:
\sqljdbc_\\sqljdbc.jar
\sqljdbc_\\sqljdbc4.jar
The following is an example of the CLASSPATH statement that is used for a Windows application:
CLASSPATH =.;C:\Program Files\Microsoft JDBC Driver 4.0 for SQL Server\sqljdbc_4.0\enu\sqljdbc.jar
The following is an example of the CLASSPATH statement that is used for a Unix/Linux application:
CLASSPATH =.:/home/usr1/mssqlserverjdbc/Driver/sqljdbc_4.0/enu/sqljdbc.jar
You must make sure that the CLASSPATH statement contains only one Microsoft JDBC Driver for SQL Server, such as either sqljdbc.jar or sqljdbc4.jar.
For more information, please see:
http://support.microsoft.com/kb/313100
http://msdn.microsoft.com/en-us/library/ms378526.aspx
first Please download correct sql driver and then check your are using correct connection driver as per operating system. then once you have to test your connection if its working fine then you will go to next .
so please check this url
microsift sql server driver for linux
https://msdn.microsoft.com/en-us/library/hh568451(v=sql.110).aspx
my sql server driver for linux
https://dev.mysql.com/downloads/connector/j/5.0.html