Hi Everybody!! 

I am working on library management system project. Below is my LibraryCollection class. I would like to call my checkOutMaterial() method in the main class. 

I need help on how to call the method.  Any help would be appreciated. 

public class LibraryCollection 
{
	private int collectionMaxSize; 
	private Material[] libraryCollection; 
	
	public LibraryCollection(int theMaxSize)
	{
		collectionMaxSize = theMaxSize; 
		libraryCollection = new Material[collectionMaxSize]; 
	}
	
	
	public LibraryCollection(int theCollectSize, Material[] theArray)
	{
		collectionMaxSize = theCollectSize; 
		libraryCollection = theArray; 
	}

    //Material ID & checkedOutPtron ID; 
    public boolean checkOutMaterial(String matrlID, String patronId)
    {
        Material thisMaterial = findMaterial(matrlID); 
        if(thisMaterial == null) 
        {
            System.out.println("The material doesn't exist" ); 
            return false; 
        }
        if(thisMaterial.checkedOut())
        {
            System.out.println("The material has been already checked out " ); 
            return false; 
        }
        thisMaterial.setCheckedOut(true);
        thisMaterial.setPatronCheckout(Integer.parseInt(patronId));//Convert string value into int

    return true; 
    }

//Material Class

public class Material 
{
    private static int materialID = 0 ; 
    private int mtrId; 
    private String title; 
    private boolean checkedOut ;
    private int checkedOutPatron; 


    public Material()
    {
        mtrId = 0; 
        title = ""; 
        checkedOut = false; 
        checkedOutPatron = 0; 
        }

    public Material(int theId, String theTitle)
    {
        mtrId = theId; 
        title = theTitle; 
    }

    //Getter Method 
    public String getMaterialId()
    {
        return mtrId + "";  
    }

    public String getTitle()
    {
        return title; 
    }

    public void setCheckedOut(boolean theCheckout)
    {
        checkedOut = theCheckout; 
    }

    public void setPatronCheckout(int patronCheckout)
    {
        checkedOutPatron = patronCheckout; 
    }


    public boolean checkedOut()
    {
        return checkedOut;
    }
    public int getCheckedOutPatron()
    {
        return checkedOutPatron; 
    }


    //ToString Method  
    public String toString()
        {
        return " \nMaterial ID: " + mtrId + " \nMaterial Title: " + title + " \nChecked Out: " 
        + checkedOut + " \nPatron check out: " + checkedOutPatron; 
        }

    public static int getNextID()
        {
        materialID++; 
        return materialID;
        }
}