I'm working on a program for fun but the MySQL driver and connection code isn't working properly I got the error
Error: no suitable driver found
MeanWhile my code contains the Class.forName("com.mysql.jdbc.Driver"); line. I have the newest MySQL jar file in my class path. any suggestions I could try to fix the problem
private void connect() {
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
con = DriverManager.getConnection(URL,user,pass);
stmt = con.createStatement();
} catch (Exception e) {
error = true;
e.printStackTrace();
}
}
Your issue is in the syntax of the URL which is not correct you forgot the colon after mysql, it should be jdbc:mysql://... for more details about the syntax of the URL in case of mysql please refer to this web page
Related
I have a class that tries to connect to a Heroku database:
public class ConnectionFactory {
public Connection getConnection() {
System.out.println("Conectando ao banco");
try {
return DriverManager.getConnection("connectionstring", "username", "password");
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
What it returns is:
java.lang.RuntimeException: java.sql.SQLException: No suitable driver
found for
jdbc:postgres://osnvehqhufnxzr:TS3Qt37c_HHbGRNKw3yk7g88fp#ec2-54-225-93-34.compute-1.amazonaws.com:5432/d39mfq0odt56bv
I already tried postgresql-9.3-1103.jdbc3.jar and postgresql-9.4.1209.jre6.jar
in the Build Path of the project. What I am doing wrong?
Use postgresql in your JDBC URL and not postgres.
Also, you need to change your DB password (because you posted it publicly) by running this command:
$ heroku pg:credentials DATABASE --reset
You need to load the driver class first by the class loader:
Class.forName("org.postgresql.Driver");
Connection conn = DriverManager.getConnection(...);
Also see: What is the purpose of 'Class.forName("MY_JDBC_DRIVER")'?
The solution was simple, System.getenv("JDBC_DATABASE_URL") returns it in server and it does the correct configuration of login and password.
public Connection getConnection() throws URISyntaxException, SQLException
{
String urlDB = System.getenv("JDBC_DATABASE_URL");
return DriverManager.getConnection(urlDB);
}
I'm trying to connect my DB with a Java Application i'm creating. What I got so far:
public class DBConnect {
public void DBConnect() {
try {
DBConnect DBConnect = null;
String url = "jdbc:mysql://localhost:3306/ähs_system";
String uName = "**";
String uPass = "**";
// Connection conn = DriverManager.getConnection(url, uName, uPass);
System.out.println("DB Connected");
}
catch (Exception Err) {
System.out.println("Error while connecting: " + Err.getMessage());
System.exit(0);
}
}
}
It's a runnable code although i'm still able to run the code without any error messages if I change my uName and/or Upass. So based on that information i'm gonna say that it's not actually connecting to the database at all...
Anyone with a few tips or tricks I can use?
I've loaded the DB in services and I am able to reach it and add data and run other SQL commands within netbeans but that's basically it. I've also loaded the mysql-connector-java-5.1.35 driver.
Run Code:
public static void main(String args[]) {
try {
DBConnect DBConnect = new DBConnect ();
DBConnect.DBConnect();
}
catch (Exception e){
System.out.println("Cannot connect to DB. Error: " + e.getMessage());
}
Let me know if you need any furthur information!
Updating property file: C:\Users\Johan\Documents\NetBeansProjects\KiltenRos\build\built-jar.properties
Compiling 1 source file to C:\Users\Johan\Documents\NetBeansProjects\KiltenRos\build\classes
C:\Users\Johan\Documents\NetBeansProjects\KiltenRos\src\kiltenros\DBConnect.java:23: error: incompatible types: java.sql.Connection cannot be converted to kiltenros.Connection
Connection conn = DriverManager.getConnection(url, uName, uPass);
1 error
C:\Users\Johan\Documents\NetBeansProjects\KiltenRos\nbproject\build-impl.xml:923: The following error occurred while executing this line:
C:\Users\Johan\Documents\NetBeansProjects\KiltenRos\nbproject\build-impl.xml:263: Compile failed; see the compiler error output for details.
BUILD FAILED (total time: 0 seconds)
the error log is clear
java.sql.Connection cannot be converted to kiltenros.Connection
it seems that you imported the wrong class in the beginning of your class
DriverManager.getConnection(url, uName, uPass) return you instance of java.sql.Connection.
btw, change your local variable DBConnect to dbConnect so it won't has the same name as your class DBConnect and it will follow the java convention (lowercase on 1st letter of a variable)
I've very little experience with MySQL, but I avoid using "ä" in a database name. Perhaps, the underscore isn't allowed.
As per your stacktrace it seems you have not imported the correct Connection class. Delete the Connection file in your project and import java.sql.Connection.
The problem seemed to be a corrupted rs2xml.jar file. Once I reloaded it and it worked.
I have the following issue with my code :
import java.sql.*;
public class App {
public static void main(String[] args){
String url = "jdbc:mysql://localhost:3306" ;
try{
Class.forName("com.mysql.jdbc.Driver");
}
catch(ClassNotFoundException e)
{ System.out.println("Eroare incarcare driver!\n" + e);
return;
}
try{
Connection con = DriverManager.getConnection(url);
// Golim tabelul persoane
String sql = "DELETE FROM persoane";
Statement stmt = con.createStatement();
stmt.executeUpdate(sql);
stmt.execute("CREATE DATABASE IF NOT EXISTS test");
stmt.execute("USE test");
i get the exception...any idea how i can make this work? thx.
enter code here
You need to download and add the jdbc connector to your classpath.
http://dev.mysql.com/downloads/connector/j/
java.lang.ClassNotFoundException occured due to "class not found" in your project/war/ear. Exception is very self explanatory, How to solve it.
In your case:
Add com.mysql.jdbc.Driver driver class/jar in your build/deployment/lib path you can
download it HERE
Read here
Offical
Make sure you have the MySQL driver on your application classpath.
Change
Connection con = DriverManager.getConnection(url);
to
Connection con = DriverManager.getConnection(url,"username","password");
and replace it with yourusername and password
I am using Eclipse and tomcat 7. I have little experience with either product and for that matter Java itself. I was trying to connect to a derby database from a Servlet. Initially, all I had in my doGet() is the following:
conn = DriverManager.getConnection(connectionURL);
I have connectionURL defined as
static private String connectionURL = "jdbc:derby://localhost:1527/seconddb";
Then I added the following to the Build Path and Deployment Assembly.
C:\DERBY\db-derby-10.10.1.1-bin\lib\derbyclient.jar
That is all I did. I sort of assumed that Tomcat will find the driver class and load it. I got the following error
java.sql.SQLException: No suitable driver found for jdbc:derby://localhost:1527/seconddb
Then I went on to add the following code in doGet() to load the driver class:
try {
Class.forName("org.apache.derby.jdbc.ClientDriver");
}
catch(ClassNotFoundException ex) {
System.out.println("Error: unable to load driver class!");
System.exit(1);
}
Now it worked. I thought that after Java 1.4 there was no need to explicitly load JDBC driver class. So what am I doing wrong here? I have given the entire code below.
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Connection conn = null;
try {
Class.forName("org.apache.derby.jdbc.ClientDriver");
}
catch(ClassNotFoundException ex) {
System.out.println("Error: unable to load driver class!");
System.exit(1);
}
try {
conn = DriverManager.getConnection(connectionURL);
//DriverManager.getConnection("jdbc:derby://localhost:1527/testdb;create=true");
}
catch (SQLException e) {
e.printStackTrace();
}
PrintWriter p = response.getWriter ();
p.println("Connected to database");
try {
if (conn != null) {
conn.close();
}
}
catch (SQLException e) {
e.printStackTrace();
}
}
I am using java 1.7
I cannot really explain why, but here is how I do :
if the driver is located in the war, I must call Class.forName("...Driver"); in in initialization method somewhere in the web application.
if the driver is located in Tomcat libraries, it is automacally loaded when I need it.
I know it's more a rule of thumb than a clear explaination, but my knowledge in class loading does not allow me to a better answer ...
Your Derby driver doesn't support the JDBC 4 auto-loading, so you have to do it manually. Try to find a more up to date version.
I could be wrong here but in your second code sample connectionURL
static private String connectionURL = "jdbc:derby://localhost:1527/seconddb";
doesn't include "create=true"; to complete the statement. In your full code sample it's included, but commented out.
I have a problem with connecting my java and mysql database was working fine yesterday but now is not working here is my code.
public static void main(String[] args) {
try
{
Class.forName ("com.mysql.jdbc.Driver");
}
catch (ClassNotFoundException e)
{
System.out.println ("Could not load the driver");
}
String user, pass, host, database;
user = "Michael";
pass = "Blaine22";
host = "localhost";
database = "maintenance_work";
Connection conn = DriverManager.getConnection
("jdbc:mysql://"+host+":3306/"+database, user, pass);
conn.setAutoCommit(false);
//Menu code:
appSchoolMaintenance newWork = new appSchoolMaintenance();
newWork.statement1(); // opens the start method
}
Add MySQL JDBC driver (you can get it here: http://dev.mysql.com/downloads/connector/j/) to application's classpath and remove unnecessary piece of code:
try
{
Class.forName ("com.mysql.jdbc.Driver");
}
catch (ClassNotFoundException e)
{
System.out.println ("Could not load the driver");
}
You can try to connect directly with MySQL JDBC driver
com.mysql.jdbc.Driver driver = new com.mysql.jdbc.Driver();
Connection conn = driver.
connect("jdbc:mysql://localhost/test?user=root&password=root", null);
if this code does compile you are missing MySQL JDBC driver on the classpath
Started to work again - tried all the suggestions but started working again no rhyme or reason to it! thanks for the help though