I have 3 sql tables: professors(prof_id, name), professors_courses(prof_id, course_id) and courses(course_id, title).
professors_courses is the bridge table between professors and courses.
In
CourseAssignments.java I search which courses belong to professor x, after user enters a professor "name".
Course.java
Same with
Professor.java:
...................
Same with
PC.java:
..................
ArrayList<PC> results contains prof_id <-> course_id
ArrayList<Course> courses contains course_id <-> title (identical with the table "courses")
I need these for example because let's say:
In "professors" table we have prof_id: 5, name: John;
In "professors_courses" we have prof_id: 5, course_id: 1
prof_id: 5, course_id: 9
In "courses" table we have course_id: 1, title: French
course_id: 9, title: Spanish
User enters: "John"
In ArrayList "results" I store:
prof_id: 5, course_id: 1 and prof_id: 5, course_id: 9
So it's similar with the bridge table, but only contains the info regarding "John".
In
String cs[] I want to store all the courses of "John", so cs[] = {"French", "Spanish"}
All in all I want to take only the "title" fields from ArrayList "courses" and store them into a String array (cs[]).
In
JSP I would display the titles:
I have Exception at the array:
org.apache.jasper.JasperException: java.lang.NullPointerException
