I'm using MySQL 5.5 with its defaults. I created a user/password and ran a script creating a database called employees. Through the command prompt I can access the database:
mysql -u user -p
SELECT * FROM employees
In my Java application, I am unable to connect. I have tried these URLs, as well as others, but nothing works:
"jdbc:mysql://localhost/employees" "user" "password"
"jdbc:mysql://localhost:3306/employees" "user" "password"
"jdbc:mysql:///employees?user=user&password=password"
Here's the relevant code:
public Main()
{
try {
connection = DriverManager.getConnection(url);
//connection = DriverManager.getConnection(url, user, password);
// I don't know what else to try
} catch (SQLException ex) {
System.out.print(ex + "\n\n");
}
}
Make sure you have Mysql driver jar in the class path and check MySQL documentation: http://dev.mysql.com/doc/refman/5.0/en/connector-j-usagenotes-basic.html
The error tells me that either
ConnectorJ driver is not in your classpath.
OR
When using DriverManager, the jdbc.drivers system property has not been populated with the location of the Connector/J driver.
OR
The format of your connection URL is incorrect, or you are referencing the wrong JDBC driver.
In your scenario, it is the list item #1 which is the cause of the issue you are facing.
I would use something like below code snippet to get the connection object.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
Connection conn = null;
...
try {
conn =
DriverManager.getConnection("jdbc:mysql://localhost/employees?" +
"user=user&password=password");
// Do something with the Connection
...
} catch (SQLException ex) {
// handle any errors
System.out.println("SQLException: " + ex.getMessage());
System.out.println("SQLState: " + ex.getSQLState());
System.out.println("VendorError: " + ex.getErrorCode());
}
Related
Project details:
| mysql-connector-java version : 8.0.27 |
| JDK version : 15.0.1 |
I am unable to make a connection to the MySQL database hosted on docker using Java. I have attached my code below for reference.
Note : I am able to make a connection to the database using python instead of java while making no changes to the connection details whatsoever. This problem only persists with java.
`
import java.sql.*;
public class TestJDBCMySQL
{ public static void main(String[] args)
{ String url = "jdbc:mysql://localhost/workson";
String uid = "retracted";
String pw = "retracted";
try ( Connection con = DriverManager.getConnection(url, uid, pw);
Statement stmt = con.createStatement();)
{
ResultSet rst = stmt.executeQuery("SELECT ename,salary FROM emp");
System.out.println("Employee Name,Salary");
while (rst.next())
{ System.out.println(rst.getString("ename")+","+rst.getDouble("salary"));
}
}
catch (SQLException ex)
{
System.err.println("SQLException: " + ex);
}
}
}
`
What I've done so far :
Creating a new user and granting all privileges using MySQL workbench
Verifying credentials. I was able to connect to the database using the docker cli with the exact same credentials.
Ensuring the database exists ( it does )
Add the mysql-connector-java to the reference library in VsCode
Specifying the port in the connection URL
I was making this java application, it works fine in Netbeans but when I tried to use the .jar out of Netbeans the app doesn't load the db. I'm using the derby.jar to make the db. Also the main problem it's the connection class in the public Connection CargarDB()
I'm tried changing my URL and surrounding all the block with a Try...Catch and it's not working yet.
public Connection CargarDB(){
Connection con;
String barra = File.separator;
String prjt = System.getProperty("user.dir") + barra + "Registros";
try {
Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
String db = "jdbc:derby:" + prjt;
con = DriverManager.getConnection(db);
System.out.println("Base de datos cargada");
return con;
} catch (ClassNotFoundException | SQLException ex) {
System.out.println("Error " + ex);
}
return null;
}
It doesn't give an error in Netbeans but in the derby document in the dist folder show me this:
-java.sql.SQLException: Database 'C:\Users\huevo\Documents\JAVA\Proyecto_T\dist\Registros' not found.
-Caused by: ERROR XJ004: Database 'C:\Users\huevo\Documents\JAVA\Proyecto_T\dist\Registros' not found.
I expect the output of my db show me the results in my JTable but it doesn't show anything
Hello im trying to connect to a mysql database using JDBC my code is below.I get an error as such No suitable driver found.Searching around I found that the usual error is syntax or missing the jar file from the class path.I tried both of these solutions and dont know what to do next it wont connect.Also to manage the databases I have WAMP and mySQL workbench installed not sure if its related.
package test.jdbc;
import java.sql.*;
public class jdbctester {
public static void main(String[] args)
{
try
{
Connection myconn=DriverManager.getConnection("jdbc:mysql://localhost:3306/voting","root","Vanquish123");
Statement myStmt=myconn.createStatement();
ResultSet myRs=myStmt.executeQuery("select * from electoral");
/*
while(myRs.next())
{
System.out.println(myRs.getString("state")+","+myRs.getString("perDem"));
}
*/
}
catch(Exception exc)
{
exc.printStackTrace();
}
}
}
Try this:
Class.forName("fully qualified driver class name");
Java Class.forName, JDBC connection loading driver
this post states that you should not need it but it will not hurt you to try.
you have to add "com.mysql.jdbc_5.1.5.jar" in to your project build path... go to project property>build Path> library> add external jar and add jar file.
Connection conn = null;
try {
// Register JDBC driver
Class.forName(DRIVER).newInstance();
// Open a connection
conn = DriverManager.getConnection(Local_URL + , USERNAME, PASSWORD);
System.out.println("Connected Database Successfully...\n\n");
} catch (Exception se) {
throw new AppException("Failed to create Local Database connection", se);
}
return conn;
Question has been updated (The DriverManager is no longer loaded manually and instead the getConnection() method is used):
package guii;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.SQLException;
/**
* This program demonstrates how to establish database connection to Microsoft
* SQL Server.
* #author www.codejava.net
*
*/
public class JdbcSQLServerConnection {
public static void main(String[] args) {
Connection conn = null;
try {
String dbURL = "jdbc:sqlserver://ASUS\\YES:1433";
String user = "TestingUser";
String pass = "12345";
conn = DriverManager.getConnection(dbURL, user, pass);
if (conn != null) {
DatabaseMetaData dm = (DatabaseMetaData) conn.getMetaData();
System.out.println("Driver name: " + dm.getDriverName());
System.out.println("Driver version: " + dm.getDriverVersion());
System.out.println("Product name: " + dm.getDatabaseProductName());
System.out.println("Product version: " + dm.getDatabaseProductVersion());
}
} catch (SQLException ex) {
ex.printStackTrace();
} finally {
try {
if (conn != null && !conn.isClosed()) {
conn.close();
}
} catch (SQLException ex) {
ex.printStackTrace();
}
}
}
}
The problem is the resulting Exception of this code. I can't find out know the reason why that particular exception is thrown.
The username, password and servername were double checked and they are definitively correct.
Currently this exception is thrown:
com.microsoft.sqlserver.jdbc.SQLServerException: Login failed for user 'TestingUser'.
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(SQLServerException.java:196)
at com.microsoft.sqlserver.jdbc.TDSTokenHandler.onEOF(tdsparser.java:246)
at com.microsoft.sqlserver.jdbc.TDSParser.parse(tdsparser.java:83)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.sendLogon(SQLServerConnection.java:2532)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.logon(SQLServerConnection.java:1929)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.access$000(SQLServerConnection.java:41)
at com.microsoft.sqlserver.jdbc.SQLServerConnection$LogonCommand.doExecute(SQLServerConnection.java:1917)
at com.microsoft.sqlserver.jdbc.TDSCommand.execute(IOBuffer.java:4026)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(SQLServerConnection.java:1416)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:1061)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:833)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:716)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:841)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at guii.JdbcSQLServerConnection.main(JdbcSQLServerConnection.java:25)
Trouble Shooting Notes
Use integratedSecurity=true again
Check if you have the sqljdbc_auch.dll in your system32 folder
Check out this link
Make sure you use the correct one (32 vs 64 bit)
Make sure the sqljdbc_auch.dll is in the Windows system path
Check if the properties of your Server instance are set correctly: access rights, make sure it actually listens in the port 1433, ...
check out this link and don't just look at the accepted answer but the other two as well.
make sure your firewall does not prevent any connections
check out if your Java Version matches the jdbc Version you use sqljdbc4.2 needs Java 1.8, jdbc4.1 needs java 1.7. look here
Hello I am trying to run a java file in cmd (Windows) with this:
C:\test>java -cp c:\test\postgresql-9.3-1102.jdbc41.jar;c:\test JDBCExample
where postgresql-9.3-1102.jdbc41.jar & JDBCExample are already in the folder "test".
and JDBCExample.java is:
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.SQLException;
public class JDBCExample {
public static void main(String[] args) {
System.out.println("-------- PostgreSQL "
+ "JDBC Connection Testing ------------");
try {
Class.forName("org.postgresql.Driver");
} catch (ClassNotFoundException e) {
System.out.println("Where is your PostgreSQL JDBC Driver? "
+ "Include in your library path!");
e.printStackTrace();
return;
}
System.out.println("PostgreSQL JDBC Driver Registered!");
Connection connection = null;
try {
connection = DriverManager.getConnection(
"jdbc:postgresql://127.0.0.1:5432/testdb", "java_postgres",
"4scoreand7yearsago");
} catch (SQLException e) {
System.out.println("Connection Failed! Check output console");
e.printStackTrace();
return;
}
if (connection != null) {
System.out.println("You made it, take control your database now!");
} else {
System.out.println("Failed to make connection!");
}
}
}
I have tried to run a simple "Hello World" java file in the same "test" folder yet it also says the same error.
And next, I also tried changing directory to a source folder of a .java file which I am REALLY SURE that it works perfect in Netbeans or Eclipse, (sorting algo and etc), yet still in the cmd it says the same error when compiling. :(
Any help? Also, I already added in the Path of my computer's Environment Variables a "C:\Program Files\Java\jdk1.7.0_45\bin;" and added a new one named CLASSPATH where it points to a "C:\Program Files\Java\jdk1.7.0_45\bin;C:\Program Files\Java\jre7\bin" but to no avail, still the same error.
OR COULD ANY OF YOU JUST HELP ME FIND ANOTHER WAY OF SETTING UP THE JDBC DRIVE. THAT'S ALL THANK YOU. T_T
My bad, it's only a matter of compilation and running problem.
/> javac JDBCExample.java
/> java JBDCExample
Sorry for the disturbance people! xD