Может ли кто-нибудь помочь мне решить эту проблему ?

public class student {
    private String name;

    private int id;
    private lesson[]listLesson;
    private int size;
    private int number=0;
    
   
    public student(String name){
        this.name=name;
        listLesson = new lesson[size];
        this.size=5;
    }
    public boolean isExist(lesson l){
        for(int i=0; i < number; i++)
            if(listLesson[i].equals(l))
                if(listLesson[i].getNote()>=60)
                    return true;
        return false;
    }
    public void addLesson(lesson l){     
        if(!this.isExist(l)){
            if(number==size){
               lesson[] newList = new lesson[size+1];
               for(int i=0; i < size; i++){
                   newList[i]=listLesson[i];
               }
               listLesson=newList;
               size++;     
                // System.out.println(listLesson);
            }
            
            listLesson[number]= l;
            number++;
       }
    
        else
            System.out.println("Already passed :"+ l);
            
    }

    public student(String name, int id) {
        this.name = name;
        this.id = id;
    }
   
    public void deleteLesson(lesson l){
        int index=existList(l);
        if(index!=-1){
            lesson []newL=new lesson[size-1];
            for(int i=0;i<index;i++){
                newL[i]=listLesson[i];
            }
            for(int i=index+1;i<size-1;i++){
                newL[i]=listLesson[i+1];
             
            }
               listLesson=newL;
                size--;           
                
        }else{
            System.err.println("No Exist!");
        }
        
    }
    
        public int existList(lesson l){
        for(int i=0;i<number;i++){
            if(listLesson[i].equals(l.getCode())){
                return i;
            }
        }
        return -1;
    }

    public lesson[] getListLesson() {
        return listLesson;
    }





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

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

    public void setListLesson(lesson l) {
        this.listLesson=new lesson[size];
    }

    public String getName() {
        return name;
    }

    public int getId() {
        return id;
    }

    public boolean equals(student s) {
        if (this.id == s.id && this.name.equals(s.name)) {
            return true;
        }
        return false;
    }

 


    
   public String toString() {        
 String res="{";
  int i;
  for(i=0;i<size-1;i++){
      if(listLesson.length==0)
          res+="-, ";
      else
      res+=listLesson[i]+", ";
      
  }
  if(listLesson.length==0)
      res+="-";
  else
  res+=listLesson[i];
 
  return "student{" + "name=" + name + ", id=" + id + res+"}";
          }

};