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.
Related
I have a problem when running my code in NetBeans in order to see if mySQL is connected. This is the code:
public static void main(String[] args) {
Connection connect = null;
try{
connect = DriverManager.getConnection("jdbc:mysql://localhost:3306/tUsers?autoReconnect=true/useSSL=TRUE","root","password");
if(connect!=null)
{
System.out.println("Connected");
}
}catch (Exception e)
{
System.out.println("RIP");
}
}
}
when I run it prints out "RIP". When I debugged it line by line, it went from the "connect = DriverManager.getConnection..." to "System.out.println("RIP"), and when I look at the "Exception e" it says "e = (java.sql.SQLNonTransientConnectionException) java.sql.SQLNonTransientConnectionException: Cannot load connection class because of underlying exception: com.mysql.cj.exceptions.WrongArgumentException: Malformed database URL, failed to parse the connection string near '=TRUE'."
Now, why is that?????
I think you need to add
Class.forName("com.mysql.jdbc.Driver"); .
Also, make sure everything in Connection conn = DriverManager.getConnection (String url, String user, String password); are set correctly.
From the url format in your code, it's like you are trying to get direct connect to specific table tUsers in your database. And I dont think that would work. Correct me if I'm wrong whether it's literally your database name or not.
Because the basic url format i know, should be like jdbc:mysql://localhost:3306/yourDBname .
If you already set the url correctly as is written in your post, then the code is
public static void main(String[] args) {
try{
Class.forName("com.mysql.jdbc.Driver");
Connection connect = DriverManager.getConnection("jdbc:mysql://localhost:3306/tUsers?autoReconnect=true/useSSL=TRUE","root","password");
if(connect!=null)
{
System.out.println("Connected");
}
}catch (Exception e)
{
System.out.println("RIP");
}}}
Hope that could do the work.
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
I am following a tutorial on connecting my SQLite database to a Java application.
When I run the program I get the following error in the console of NetBeans:
run:
Error connecting to the databasejava.sql.SQLException: No suitable
driver found for jdbc:C:\Users\lawman\Documents\Java Working
Directory\LoginSql\src\project123.sqlite
BUILD SUCCESSFUL (total time: 0 seconds)
Here is my directory:
I have code to connect to the database in class tobecalledbymain.
I have main in mainclass which creates an instance of tobecalledbymain.
In my library file, I have sqlite-jdbcs.jar imported.
Here is the code for tobecalledinmain:
import java.sql.*;
public class tobecalledinmain {
public tobecalledinmain(){
Connection con = null;
Statement st=null;
ResultSet rs=null;
try
{
Class.forName("org.sqlite.JDBC");
con = DriverManager.getConnection("jdbc:C:\\Users\\lawman\\Documents\\"
+ "Java Working Directory\\LoginSql\\"
+ "src\\project123.sqlite");
st=con.createStatement();
//select all records from the table employee
//table has three firlds: employeeid,name and surname
rs=st.executeQuery("SELECT * FROM Employee;");
while (rs.next())
{
int id = rs.getInt("Employeeid");
String name = rs.getString("Name");
System.out.println("id = " + id);
System.out.println("name= " + name);
System.out.println();
}
rs.close();
st.close();
con.close();
}catch(Exception e)
{
System.out.println("Error connecting to the database" + e);
}
}
}
Here is the mainclass code:
public class mainClass {
public static void main(String[] args){
new tobecalledinmain();
}
}
;;
I am not sure why we need to semi-colons!
Anyway, when the tutorial concludes he gets a result from the console. I get the said error message.
What are the drivers in the error message referring to and how do I get them?
Your jdbc connection string does not specify sqlite. Try this, and use forward slashes.
Connection con = DriverManager.getConnection("jdbc:sqlite:C:/PATH/TO/database.db");
This was the WRONG answer, pls disregard.
You need to add the .jar for the SQLite database driver to your classpath when you run your code. See https://bitbucket.org/xerial/sqlite-jdbc
You can see how to do that in Netbeans here: How to add a JAR in NetBeans
I am using jdk1.8 and I am trying to execute a jdbc program manually on oracle 8i. My code is compiling without any error but at the run time its showing error-no suitable driver found for jdbc:oracle:thin:#localhost:1521:orcl. I have already set the class path for jar file. I am using ojdbc7.jar file.
My code is:
import java.sql.*;
class Database
{
public static void main(String arg[])
{
try
{
String url="jdbc:orcl:thin:#localhost:1521:orcl";
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection(url,"scott","tiger");
Statement st=con.createStatement();
ResultSet rs=st.executeQuery("select * from aj1");
while(rs.next())
{
System.out.println("\n"+rs.getInt(1)+" "+rs.getString(2));
}
}
catch(Exception e){e.printStackTrace();}
}
}
Kindly give the solution for this:
You url String must be
String url="jdbc:oracle:thin:#localhost:1521:orcl";
instead of
String url="jdbc:orcl:thin:#localhost:1521:orcl";
and try.
import java.sql.*;
public class Connect
{
public static void main (String[] args)
{
Connection conn = null;
try
{
String userName = "root";
String password = "password123!";
String url = "jdbc:oracle:thin:#localhost:3306:procomport";
//Class.forName ("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection(url, userName, password);
//Connection connection = DriverManager.getConnection(url , userName, password);
System.out.println ("Database connection established");
}
catch (Exception e)
{
System.err.println ("Cannot connect to database server");
}
finally
{
if (conn != null)
{
try
{
conn.close ();
System.out.println ("Database connection terminated");
}
catch (Exception e) { /* ignore close errors */ }
}
}
}
}
This is my code I have multiple different databases but it wont connect to any of them what's the problem with this? I keep getting the error it cannot connect to the database. Although I can connect to it using other management tools is it a driver issue? How would I be able to tell if I had the drivers necessary?
The code you've provided to connect to the database won't connect to either MySQL nor Oracle as it stands because it's a mish-mash of attempts to connect to both.
For Oracle, the code should look something like:
String userName = "root";
String password = "password123!";
String url = "jdbc:oracle:thin:#localhost:1521:procomport";
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection(url, userName, password);
(assuming you have a user called root on Oracle, and the Oracle SID is procomport). Note in particular the change of port number: MySQL typically uses 3306, Oracle uses 1521.
For MySQL the connection code should look like:
String userName = "root";
String password = "password123!";
String url = "jdbc:mysql://localhost:3306/procomport";
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(url, userName, password);
(assuming your MySQL database is called procomport). Note the different style of connection URL and the driver class name.
The Oracle driver is typically in a JAR file named ojdbc6.jar, and the MySQL in a JAR named something like mysql-connector-java-5.1.18-bin.jar.
Finally, when you write something like
catch (Exception e)
{
System.err.println ("Cannot connect to database server");
}
you really aren't helping yourself. The exception e will almost certainly contain the reason why your database connection code isn't working, but by deliberately ignoring it you're making it much harder for yourself to figure out what has gone wrong.
To be honest with you, I'd be tempted to declare the main method throws Exception (by adding this to the end of the public static void main... line), and then you can delete your unhelpful catch block. If an exception is thrown and not handled within main, the JVM will print the stack trace for you before it exits.
After your:
System.err.println();
Place a:
e.printStacktrace();
Then you will see real error message. Probably the driver classes are not in the classpath.
Hope this will help you
Uncomment the line Class.forName("oracle.jdbc.driver.OracleDriver");
Make sure you have the Oracle dirver "oracle.jdbc.driver.OracleDriver" in the classpath