Two Different types of Arrays into the first Array

I have created a ArrayList<Student> in a object StudentList list1 that is saving[Serialization] a student's information (name,id,age,gpa,etc) into the list1, so that the list1[0] = 1st student's info, then the list1[1] = 2nd student's info and so on.

Also a new ArrayList<Subject> in a object SubjectList list2 for all subject of a student at index 0 example list2[0]=(java,math,etc) [for first student] list2[1]=(c++,english,etc) [for second student] saved in a file.

I want to add the subject next to the student info:

list1 index[0]=1st Student info, index[1]=1st Student's Subjects.

index[2]=1st Student info,index[3]=1st Student's Subjects.

I am stuck with this simple problem.Help please. My codes too much messy couldn't post, Sorry for that.

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