Member Avatar for london-G

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

  • 5 Contributors
  • 8 Replies
  • 377 Views
  • 20 Hours Discussion Span
  • Latest Post Latest Post by london-G
Member Avatar for JamesCherrill

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

is the server really called "host"?

Member Avatar for london-G

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

Member Avatar for Traevel

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).

Member Avatar for JamesCherrill

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

Member Avatar for Jack_11

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

Member Avatar for cool_zephyr

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

Edited by cool_zephyr
Member Avatar for london-G

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

Member Avatar for london-G

@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.

Edited by london-G
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