Hello,

I am trying to connect to a hosted database on netbeans(java).

So far I have the following:

Connection con = null;
        Properties conProps = new Properties();
        conProps.setProperty("user", "user");
        conProps.setProperty("password", "password");

        try {
            con = DriverManager.getConnection("jdbc:mysql://host:3306/dbname", conProps);
            String sql = ("SELECT * from products");
            st = (com.mysql.jdbc.PreparedStatement) con.prepareStatement(sql);
            st.executeQuery();

            rs = st.getResultSet();

So my host looks something like this: XX.XXX.X.XX which represents numbers.

I am definelty doing something wrong as it is not connected.

I am sure that the host is correct as well as username, password and db name.

Error is :

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1117)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:355)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2461)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2498)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2283)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:822)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:404)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:317)
    at java.sql.DriverManager.getConnection(DriverManager.java:571)
    at java.sql.DriverManager.getConnection(DriverManager.java:187)
    at Table.populateList2(Table.java:57)
    at Table.<init>(Table.java:34)
    at Table$3.run(Table.java:165)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:312)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)

It does work when connected to local host but not a hosted database

Re: Java db connection (not connecting) 80 80

"jdbc:mysql://host:3306/dbname"

is the server really called "host"?

Re: Java db connection (not connecting) 80 80

Nope, My host looks something like this: XX.XXX.X.XX which represents numbers.

Re: Java db connection (not connecting) 80 80

Are you hosting it yourself? Check ports and whether the host allows remote access to a MySQL database. Also check you have the proper user privileges in place (GRANT).

Re: Java db connection (not connecting) 80 80

Then you need those numbers (IP address?) in your getConnection call, not just "host"

Re: Java db connection (not connecting) 80 80

Also you might be having trouble because of the database that you're using. Such as MySQL, or MongoDB.

Re: Java db connection (not connecting) 80 80

If you are trying to connect to a real server..you need to configure the server allowing remote database connections..like adding your IP address on the remote connection list

Re: Java db connection (not connecting) 80 80

Thanks guys, I added my ip address at home so that it allows it. It worked yesterday but now I am at university and it does not work..

I tried to add the other IP address, no success. I will try again at home and let you know

Re: Java db connection (not connecting) 80 80

@James, I did not write "host" in my code. For security reasons, I did not want to add it here.

I did write the correct host address.

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