java - Fish Pond Simulation: Homework, where am I going wrong? -


this multipart question.

restrictions:

  • can't use .clone(), or collections, or system.
  • can't change different object type (i mean can't change arraylist list or not).

i think problem might haven't grasped how throw exceptions. not sure though.

here part of assignment i'm stuck on.

adds fish f fish list, if possible.

first checks if landscape in fish's location equal rock. if is, fish not added list. instead, throws illegalfishpositionexception, passing illegalfishpositionexception.fish_over_rock constructor.

next checks fish (distinct parameter) in same location parameter. if 1 found, fish not added list. instead throws illegalfishpositionexception, passing illegalfishpositionexception.two_fish_in_one_place constructor.

otherwise, adds parameter fish list.

public void addfish(fish f) {     arraylist <fish> addfish = new arraylist <fish>( fish );      if ( landscape[ f.getrow() ][ f.getcol() ] == rock ) {         throw new illegalfishpositionexception(                 illegalfishpositionexception.fish_over_rock );     }     ( fish f1 : addfish ) {         if ( ( f1.getrow() == f.getrow() &&                  f1.getcol() == f.getcol() ) || f1 == f ) {             throw new illegalfishpositionexception(                     illegalfishpositionexception.two_fish_in_one_place );         }     }     ( fish f2 : addfish ) {         if ( ( f2.getrow() != f.getrow() &&                  f2.getcol() != f.getcol() ) &&                  landscape[ f.getrow() ][ f.getcol() ] != rock ) {             fish.add( f );         }     }  }

and here second method seems logical me, failing on tests.

/* checks specified location see if has rock, fish, or plant   * in it. if so, returns false; if water, returns true. */ public boolean isspaceavailable(int r, int c) {     if ( landscape[r][c] == rock ) {         return false;     }     ( fish f : fish ) {         if ( ( f.getrow() == r ) && ( f.getcol() == c ) ) {             return false;         }     }     ( plant p : plants ) {         if ( ( p.getrow() == r ) && ( p.getcol() == c ) ) {             return false;         }     }     return true; }

i have couple of other methods dependent on addfish, if can right, it'll have cascading effect.

here junit test need pass isspaceavailable method.

@test public void testisspaceavailable() {     model m = new model(10,10,0,0,0);     fish f = new fish(1, 7, 100, fish.up);     plant p = new plant(2, 8, 100);     m.addfish(f);     m.addplant(p);     assertfalse(m.isspaceavailable(1, 7));     assertfalse(m.isspaceavailable(2, 8));     assertfalse(m.isspaceavailable(0, 0));     (int = 1; < 9; i++) {         (int j = 1; j < 9; j++) {             if ((i != 1 || j != 7) && (i != 2  || j != 8)) {                 asserttrue(m.isspaceavailable(i, j));             }         }     } }

here javadoc project if guys need through it. http://www.cs.umd.edu/class/spring2013/cmsc131-23/projects/p7/doc/index.html

i've been staring @ while , i'm throughly stuck.

addfish in bad state. remove local arraylist, if worried thread safety/concurrency use locking strategy or synchronise method. final loop wrong , redundant, time hit have satisfied conditions adding fish. can add fish plant is?

public void addfish(fish f) {      if ( landscape[ f.getrow() ][ f.getcol() ] == rock ) {         throw new illegalfishpositionexception(                 illegalfishpositionexception.fish_over_rock );     }      ( fish f1 : this.fish ) {         // fish.equals implemented if use that.         if ( f1 == f){             // fish in list nothing            // bad practice have return in middle of method            return;           } else if ( ( f1.getrow() == f.getrow() &&                  f1.getcol() == f.getcol() )) {             throw new illegalfishpositionexception(                     illegalfishpositionexception.two_fish_in_one_place );         }     }     fish.add( f );  }

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