Thread: i do not know how to solve this issue

public class CcaExercise
{
	private String academicYear;
	private String semester;
	private Student [] appList;
	private Cca [] ccaList;
 
	public CcaExercise (String academicYear, String semester, Student [] appList, Cca [] ccaList)
	{
		this.academicYear=academicYear;
		this.semester=semester;
		this.appList=appList;
		this.ccaList=ccaList;
	}
 
	public void addStudentToExercise(Student s)
	{
		for(int i=0; i< appList.length;i++)
		{
			if(appList[i]==null)
			{
				appList[i]=s;
				break;
			}
		}
	}
	public Student getStudentInExercise(String nric)
	{
		for(int i=0;i<appList.length;i++)
		{
			if(appList[i] !=null&&
				appList[i].getNric().equals(nric))
				{
					return appList[i];
				}
		}
		return null;
	}
	public void displayAllStudents()
	{
		for(int i=0; i<appList.length;i++)
		{
			if(appList[i] !=null)
			{
				System.out.println(appList[i].toString());
			}
			}
 
		}
		public void addCca(Cca c)
		{
			for(int i=0;i<ccaList.length;i++)
			{
				if(ccaList[i]==null)
				{
					ccaList[i]=c;
					break;
				}
			}
		}
		public boolean removeCca(String ccaID)
		{
			boolean result=false;
			for(int i=0;i<ccaList.length;i++)
			{	
				if(ccaList[i].getCcaID().equals(ccaID))
				{
					ccaList[i]=null;
					result=true;
					break;
				}
			}
			return result;
		}
		public void displayAllCcas()
		{
			for(int i=0;i<ccaList.length;i++)
			{
				if(ccaList[i]!=null)
				{
					System.out.println(ccaList[i].toString());
				}
			}
		}
		public Cca findMostVacancy()
		{
			//search for cca with largest number of vacancy
			int largest=0;
			Cca result=null;
			for(int i=0;i<ccaList.length;i++)
			{
				if(ccaList[i]!=null&&
					ccaList[i].getNumOfVacancy()>largest)
					{
						//update largest value
						largest=ccaList[i].getNumOfVacancy();
						//save the object having largest value
						result=ccaList[i];
					}
		}
		return result;	
}
public Cca findLeastVacancy()
{
	//search for CCA with smallest number of vacancy
	int smallest=101;
	Cca result=null;
	for(int i=0;i<ccaList.length;i++)
	{
		if(ccaList[i]!=null&&
			ccaList[i].getNumOfVacancy()<smallest)
			{
				//update the smallest value
				smallest=ccaList[i].getNumOfVacancy();
				//save the object having smallest value
				result=ccaList[i];
			}
		}
		return result;
}
public void displayAllStudentsAllCca()
{
	//print all students in all ccas
	for(int i=0;i<ccaList.length; i++)
	{
		if(ccaList[i]!=null)
		{
			ccaList[i].displayStudentList();
		}
	}
}
public int processApplications()
{
	int success=0;
	for(int i=0;i<appList.length;i++)
	{
		//for each student
		//search for CCA that student apply to
		for(int j=0;j<ccaList.length;j++)
		{
			if(ccaList[j]!=null&&
				ccaList[j].getCcaID().equals(appList[i].getCcaRequest())&&
				ccaList[j].getNumOfVacancy()>0&&
				appList[i].getCgpa()>ccaList[j].getMinEntryCgpa())
				{
					// add student to ccaLists studentList array
					ccaList[j].updateStudentList(appList[i]);
					//remove applicant from applist
					appList[i]=null;
					ccaList[j].setNumOfVacancy(ccaList[j].getNumOfVacancy()-1);
					success++;
				}
 
		}
 
	}
	return success;
 
 
}
public void displayNumberPerCca()
{
	for(int i=0;i<ccaList.length;i++)
	{
		if(ccaList[i]!=null)
		{
			System.out.println(100-ccaList[i].getNumOfVacancy());
		}
   }
 }
}

The problem are

CcaExercise.java:133: displayStudentList(java.lang.String) in Cca cannot be applied to ()
ccaList[i].displayStudentList();
^
CcaExercise.java:152: updateStudentList(java.lang.String) in Cca cannot be applied to (Student)
ccaList[j].updateStudentList(appList[i]);
^
2 errors


as i see the fault is at another class code called Cca

this is the Cca Class code

public class Cca{
 
 
	private String ccaID;
	private String name;
	private int numOfVacancy;
	private Student[]studentList;
	private double minEntryCgpa;
 
	public Cca(String ccaID,String name,int numOfVacancy,Student[]studentList,double minEntryCgpa){
 
		this.ccaID = ccaID;
		this.name = name;
		this.numOfVacancy = numOfVacancy;
		this.studentList = studentList;
		this.minEntryCgpa = minEntryCgpa;
 
	}
	public String getCcaID()
	{
 
		return ccaID;
	}
 
	public String getName()
	{
 
		return name;
	}
 
	public int getNumOfVacancy()
	{
 
		return numOfVacancy;
	}
 
	public void setNumOfVacancy(int numOfVacancy)
	{
 
		this.numOfVacancy = numOfVacancy;
	}
 
		public double getMinEntryCgpa()
	{
 
		return minEntryCgpa;
	}
 
		public void setMinEntryCgpa(double minEntryCgpa)
	{
 
		this.minEntryCgpa = minEntryCgpa;
	}
 
	public Student updateStudentList(String nric)
	{
 
		for(int count =0;count<studentList.length;count++)
		{
			if(studentList[count] != null &&
				studentList[count].getNric().equals(nric))
				{
 
				return studentList[count];
			}
		}
		return null;
	}
 
	public Student displayStudentList(String name)
	{
 
		for(int count =0;count<studentList.length;count++)
		{
			if(studentList[count] != null &&
				studentList[count].getName().equals(name))
				{	
				return studentList[count];
			}
		}
		return null;
	}
 
		public String toString()
		{
		String info = "ccaID:" +ccaID +"\nName:" +name +"\nNumOfVacancy:" +numOfVacancy;
		return info;
	}
 
}

Can anyone help me solve it thz alot