here is my controller class 
public without sharing class UpdateList {
    list<order> selectorder;
    String quoteId {set; get;}
    String selectedOrderId {set; get;}
    public List<Order> selectedOrders {set; get;}
    public Boolean orderUpdated {set; get;}    
    public UpdateList(){
        quoteId = ApexPages.currentPage().getParameters().get('quoteID');
        orderUpdated = false;
    } 
    public PageReference selectOrder(){
        selectedOrderId = ApexPages.currentPage().getParameters().get('ordersRadio');
        selectedOrders = [select Id, OrderNumber, Status from Order where id=:selectedOrderId];
        return null;
    }    
    public list<Order> getorderslist()
    {
        List<order> allords=[select Id,Ordernumber,Status from Order where quoteId=:quoteId];
        return allords;
    }    
    //call this method to update order, and copy all quote line items from quote
    public PageReference updateOrder(){     
        //get selected orderId from the list   
        selectedOrderId = ApexPages.currentPage().getParameters().get('ordersRadio');
        //get quote line items using the quoteId
        List<OrderItem> orderLines = new List<OrderItem>(); 
        for(QuoteLineItem qLine : [SELECT Id, QuoteId, PricebookEntryId, Quantity, UnitPrice, Discount, Description, ServiceDate, 
                                   Product2Id, SortOrder, ListPrice, Subtotal, TotalPrice FROM QuoteLineItem where QuoteId=:quoteId]){
            OrderItem oLine         = new OrderItem();
            oLine.OrderId           = selectedOrderId;
            oLine.PricebookEntryId  = qLine.PricebookEntryId;
            oLine.Quantity          = qLine.Quantity;
            oLine.UnitPrice         = qLine.UnitPrice;
            oLine.Description       = qLine.Description;
            oLine.ServiceDate       = qLine.ServiceDate;
            orderLines.add(oLine);
        } 
        insert orderLines;       
        orderUpdated = true;
         ApexPages.AddMessage(new ApexPages.Message(ApexPages.Severity.CONFIRM,'Record updated Successfully.Thank you!'));
        return null;       
    }    
}


here my test class
@istest (seeAllData=true)
private without sharing class TestUpdateList{
    
    Private static Account a;
    Private static Contact c;
    Private static Opportunity opp;
    Private static Quote q;
    Private static QuoteLineItem Qli;
    private static Order o;
    Static {    
        // Creating the data for Account,Contact,Opportunity,Quote and Order.
        
        a=new Account(Name='test1',Phone='9458383336');   // creating account with only mandatory Fields
        insert a;
        c = new Contact(LastName='Test',AccountId=a.Id);  // creating contact with only mandatory Fields
        insert c;
        
        // creating opportunity with only mandatory Fields
        opp = new Opportunity(Name='Test Opp',AccountId=a.Id,StageName='closedwon',CloseDate=Date.Today());
        insert opp;
        
        Pricebook2 stdPb = [select Id from Pricebook2 where isStandard=true limit 1];
        
        Product2 p = new product2(name='test',family='test',productcode='12345');
        insert p;
        System.debug('### p:'+p);
        
        PricebookEntry pbe = new PricebookEntry(pricebook2id=stdPb.id, product2id=p.id,
                                                unitprice=1.0, isActive=true,UseStandardPrice=false);
        insert pbe;
        
        // Creating Quote with only mandatory Fields
        q=new Quote(Name='testquote',opportunityId=opp.Id, pricebook2id=stdPb.id);
        insert q;
        // Creating Quote Line Items PricebookEntryId, Product2Id
        qli=new QuoteLineItem(QuoteId=q.Id,pricebookentryid=pbe.id, Quantity=12,UnitPrice=1500,Discount=0,Description='nothing',ServiceDate=system.today());
        insert qli;
        // Creating Order with mandatory Fields 
        o=new Order(AccountId=a.Id,Name='test',status='draft',EffectiveDate=system.today());
        insert o;                    
    }  
    // retreiving the order record and  working fine 25% code coverage with this method.
    Static TestMethod void Testgetorderslist(){
        Test.StartTest();

        PageReference pageRef=page.PrevOrder;
        pageRef.getParameters().put('quoteID',q.Id);
        Test.SetCurrentPageReference(pageRef);

        UpdateList ul=new UpdateList();
        List<order> orderList = ul.getorderslist();

        pageRef.getParameters().put('selectOrder',o.Id);
        ul.SelectOrder();
        ul.updateOrder();

        system.debug('test result ='+ orderList);
        system.assertEquals(orderList.size(),1);

        Test.StopTest();
    }
   
    Static TestMethod void TestselectOrder(){
        Test.StartTest();
        PageReference pageRef=page.PrevOrder;
        Test.SetCurrentPageReference(pageRef);
        ApexPages.currentPage().getParameters().put('ordersRadio',o.Id);   
        ApexPages.StandardController sc = new ApexPages.standardController(o);              
        UpdateList controller=new UpdateList();   
        controller.SelectOrder();  
        controller.UpdateOrder();
        Test.StopTest();    
    }    
}

i am getting the above error when i run my test class.
how to solve this?