java - Constructor problems with inheritance and generics -

i having hard time understanding generics inheritance. error getting is:

stage.java:66: error: constructor stage in class stage<t> cannot applied given types;         {         ^   required: arraylist<t>,double,arraylist<t>   found: no arguments   reason: actual , formal argument lists differ in length   t type-variable:     t extends object declared in class stage 

what have subclass called stage0 (an inline class of stage) inherits stage. stage0 have same functionality bar - stage0 @override method parent class. here line 63 of stage class (which beginning of stage0)

class stage0 extends stage<t> {     stage0(arraylist<t> inq, double inputtime, arraylist<t> outq)     {         inputqueue = inq;         takestime = inputtime;         outputqueue = outq;     }      @override     public boolean isstarving(double time)     {         return false;     } } 

what source of error?

cheers.

public class stage<t> // equivalent 'storage' {     private t holditem;     private boolean blocked;     private double takestime, timetaken, blockedtime, starvetime;     private arraylist<t> inputqueue, outputqueue;      public stage(arraylist<t> inq, double inputtime, arraylist<t> outq)     {         inputqueue = inq;         takestime = inputtime;         outputqueue = outq;     } 

because haven't specified call super in stage0 constructor code, compiler inserts you, though had typed this:

stage0(arraylist<t> inq, double inputtime, arraylist<t> outq) {     super();                       // <======================     inputqueue = inq;     takestime = inputtime;     outputqueue = outq; } 

from error message, appears stage has no matching constructor. error says:

constructor stage in class stage cannot applied given types...
required: arraylist,double,arraylist
found: no arguments

that is, you're trying call super() when best matching constructor can find super(arraylist<t>,double,arraylist<t>).

the solution use super explicitly, providing necessary arguments. in case, again based on error message, be:

stage0(arraylist<t> inq, double inputtime, arraylist<t> outq) {     super(inq, inputtime, outq);   // <======================     inputqueue = inq;     takestime = inputtime;     outputqueue = outq; }