I tried to connect to SQL Server 2014 but an error always occurs, how to solve it

Question

Note: I included the mssql-jdbc-6.4.0.jre7 jar file

The error:

W/System.err: com.microsoft.sqlserver.jdbc.SQLServerException: The driver could not establish a secure connection to SQL Server by using Secure Sockets Layer (SSL) encryption. Error: "Socket closed". ClientConnectionId:0c66e1a1-9a3a-4554-9137-9868b305b033

the source code:

public void click (View view)
{
    new Thread(new Runnable(){
        @Override
        public void run()
        {
            try {
                Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
                Connection con;
                con = DriverManager.getConnection("jdbc:sqlserver://IP:port;databaseName=DB;user=user;password=password");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
}).start();
}

Answer 1

好像服务器不可用，现在，检查一下