JDBC connectivity issue while connecting to college server - eclipse

Question

I have tried to connect to the college server from my workplace and receive the response:
Connection Failed! Check output console
My code:
public JDBCBasicExample() {
// TODO Auto-generated constructor stub
}
public static void main(String[] argv) {
System.out.println("-------- MySQL JDBC Connection Testing ------------");
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
System.out.println("Where is your MySQL JDBC Driver?");
e.printStackTrace();
return;
}
System.out.println("MySQL JDBC Driver Registered!");
Connection connection = null;
try {
connection = DriverManager
.getConnection("jdbc:mysql://collegeservername:portnumber/databasenameinserver",
"username","password");
} catch (SQLException e) {
System.out.println("Connection Failed! Check output console");
e.printStackTrace();
return;
}
if (connection != null) {
System.out.println("You made it, take control your database now!");
} else {
System.out.println("Failed to make connection!");
}
}
I am getting the following error:
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(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1121)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:675)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1086)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2486)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2519)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2304)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:416)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:346)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at testingdatabase.JDBCBasicExample.main(JDBCBasicExample.java:29)
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly l`enter code here`ost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3119)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:599)
... 16 more
Can someone please help me to resolve this? I am new to this and have tried many other ways like replacing collegeservername:portnumber with ip address though it didnt work. I have also tried with other remote address and port name but with no success. Kindly give me your suggestions.

Answer 1

Connection fail simple check list:
Your networking is working properly.
Is there any firewall in your college server that blocks or allows the connections from a set of IP address?
The address and port of database server is correct?? Check to make sure the external IP is actually available internally.
Does the mysql service is start?? (check the system service list and the tcp listening list, does mysql listen connection??)
Can you login your database via mysql shell from your workspace?? (open your terminal, enter mysql -h your_database_host -u your_username -p to login)
Does database allow remote access?? (Check the my.cnf file in databaes server and remove the line bind-address=127.0.0.1)