Connecting to a java DB with java program

Question

I am implementing a simple tutorial that

connects a java program to a java DB using the NetBeans 7 IDE . Here is the link to the tutorials.

http://www.homeandlearn.co.uk/java/connect_to_a_database_using_java_code.html

But when I run the project, NetBeans gives me the following error:

run:
java.lang.VerifyError: Constructor must call super() or this() before return in method   database_console.DBConnect.<init>()V at offset 0
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2442)
    at java.lang.Class.getMethod0(Class.java:2685)
    at java.lang.Class.getMethod(Class.java:1620)
    at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:492)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:484)
Exception in thread "main" Java Result: 1
BUILD SUCCESSFUL (total time: 12 seconds)

Below is the code for the project

    package database_console;

    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.SQLException;

  public static void main(String[] args) {           
            try {
          String host = "jdbc:derby://localhost:1527/Employees";
          String uName="faisal";
          String uPass="password";
          Connection con=DriverManager.getConnection(host, uName, uPass);        
            }
           catch ( SQLException err ) {
    System.out.println( err.getMessage( ) );
    }
        }
    }

any available suggestion to solve this problem

Please post your whole code (yes, don't mind if it's a code wall). — Luiggi Mendoza, Feb 24 '13 at 15:04
Are you sure you don't have the class definition? Otherwise your code would have never compiled to begin with (and no way to run it). — Luiggi Mendoza, Feb 24 '13 at 15:10
@LuiggiMendoza, my first answer was correct. But you downvoted, I tried removing class. I am getting same error OP is getting — Pradeep Simha, Feb 24 '13 at 15:13
@PradeepSimha ok, undelete it and I will upvote it (since you were the first one to find the problem). — Luiggi Mendoza, Feb 24 '13 at 15:14
If you have an IDE how did it even allow you to run that program ? — user1428716, Feb 24 '13 at 15:17
I dont think the issue is with the class missing - he would have forgot to paste it here - See the discussion here http://stackoverflow.com/questions/100107/reasons-of-getting-a-java-lang-verifyerror — user1428716, Feb 24 '13 at 15:20

score 2 · Answer 1 · edited Feb 24 '13 at 15:15

2

If your above code is what you are using, then you need to put your entire code in class.

//Package declarations (if any)
//Import packages
public class className {

    public static void main(String[] args) {
        //Other code
    }
}

edited Feb 24 '13 at 15:15

Luiggi Mendoza

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answered Feb 24 '13 at 14:59

Pradeep Simha

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but thought the public clas className in the above code is the class declaration – faisal abdulai Feb 24 '13 at 15:03
@faisalabdulai, in your code don't have either public or non-public class. – Pradeep Simha Feb 24 '13 at 15:17

score 1 · Answer 2 · answered Feb 24 '13 at 15:09

Please add class to your main(). Like following

package database_console;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBConnect 
{

    public static void main(String[] args) 
    {
        try 
        {
            String host = "jdbc:derby://localhost:1527/Employees";
            String uName = "faisal";
            String uPass = "password";
            Connection con = DriverManager.getConnection(host, uName, uPass);
        } 
        catch (SQLException err) 
        {
            System.out.println(err.getMessage());
        }
    }
}

score 0 · Accepted Answer · answered Feb 24 '13 at 15:07

0

You did not follow the tutorial you linked correctly.

Your code should look like this:

package database_console;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBConnect {  // <--- This is missing from your code

    public static void main(String[] args) {
        try {
            String host = "jdbc:derby://localhost:1527/Employees";
            String uName = "faisal";
            String uPass = "password";
            Connection con = DriverManager.getConnection(host, uName, uPass);
        } catch (SQLException err) {
            System.out.println(err.getMessage());
        }
    }  // <--- This is also missing from your code
}

And it should be in a file named DBConnect.java in a package called database_console

answered Feb 24 '13 at 15:07

user000001

32,226
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You should point that the code comes from the [tutorial](http://www.homeandlearn.co.uk/java/connect_to_a_database_using_java_code.html) not from the top of your head. – Luiggi Mendoza Feb 24 '13 at 15:09
Yes exactly. OP sais it in the question – user000001 Feb 24 '13 at 15:09
after trying your suggstion , now the NetBeans IDE underlines he class declaration with the following message duplicate class database_console.DBConnect – faisal abdulai Feb 24 '13 at 15:19
@faisalabdulai Delete the entire contents of the file `DBConnect.java` and paste the above code. It should give no compiler errors. You have something else in there that is not showing. – user000001 Feb 24 '13 at 15:21
@faisalabdulai Also clean the project and build again – user000001 Feb 24 '13 at 15:25

score 0 · Answer 4 · answered Feb 24 '13 at 15:13

this class is used to create DB connection

import java.sql.Connection;
import java.sql.*;

public class GetDBConnection 
{
    public static Connection getConnection(String[] args) 
    {
        String host = "jdbc:derby://localhost:1527/Employees";
        String uName="faisal";
        String uPass="password";
        Connection con=null;
        try 
        {
              con=DriverManager.getConnection(host, uName, uPass);        
        }
        catch ( SQLException err ) 
        {
        System.out.println( err.getMessage( ) );
        }
        return con;
    }

}

this class is used to get coonection and use it

public class UseDBConnection 
{
    public static void main(String[] args) 
    {
        GetDBConnection object = new GetDBConnection();
        System.out.println("now you can use this DB like you want it and can create as many connection as you want");
    }
}

Connecting to a java DB with java program

4 Answers4