Class for course information
Here's the list of things I would change:


Indentation (make it 2 or 4 tabs) 
Field naming is inconsistent. For example, courseid should be changed to courseId. Secondly, you should append the prefix course to all fields, or omit it at all. (Don't forget to change your methods as well).
Assuming that this is a POJO (Plain Old Java Object) class, then I would recommend removing the display() method from this class. It's simply not its responsibility to display itself(S from SOLID principles). Instead, you can modify your toString() method to look something like this:


`

public String toString() {
   return "Course ID:" + id + '\n' +
            "Course name:" + name + '\n' +
            "Course description:" + description + '\n' +
            "Credit hours:" + creditHours + '\n';
}


`
And then use it in a different object/function whose responsibility is to present information to the user. 


From my personal experience, I can say that the id field should be a String. If you are getting data from a server, and then convert that data to a POJO, the id field may cause an overflow in some situations if it's an integer. Even longdata type may cause an overflow if the id value is very long. 
I don't think it's a professional way to declare and initialize an instance of a class the way it was written. You can do both in a single line.


This is how I would have written it:

public class Course {

  private String id;
  private String name;
  private String description;
  private float creditHours;

  public void setId(String id) {
     this.id = id;
  }

  public String getId() {
     return id;
  }

  public String getName() {
     return name;
  }

  public void setCreditHours(float creditHours) {
     this.creditHours = creditHours;
  }

  public void setName(String name) {
     this.name = name;
  }

  public void setDescription(String description) {
     this.description = description;
  }

  public String getDescription() {
     return description;
  }


  public String toString() {
     return "Course ID:" + id + '\n' +
            "Course name:" + name + '\n' +
            "Course description:" + description + '\n' +
            "Credit hours:" + creditHours + '\n';
  }

  public static void main(String args[]) {
    final Course course = new Course();
    course.setCreditHours(15.6f);
    course.setDescription("BlaBla");
    course.setId("12345567878665345453123");
    course.setName("Just a boring class");

    System.out.print(course.getDescription());
  }
}


It contains some other corrections as well.

Hope this helps!

As a side note, though it seems absolutely superfluous, I would like you to know that's it's not my intention to criticize your code, I'm simply expressing my opinion based on the experience I have.