on the subject of packaging

[colton peterson]

If you have a package with two classes and one class wants to use the other class do you have to import the package even though they are in the same package?

[Ernest Friedman-Hill]

Nope. They'll both have the same "package x.y.z;" line, of course.

[Christophe Verré]

No you don't need to explicitly import it.

[colton peterson]

is there any kind of declaration you have to do so that classes in the same package can "see" each other, because I can not compile my class because it can't find my other classes. I have checked the classpath.

Let me guess. The next thing you guys will ask is "Can you post the code" so here it is

  public class Rabbit {
 
//declare variables
private ShapeIcon photo; //picture to use
 
static int totalPop = 0; //total amount of rabbits alive at one time

static int rabbitsDead = 0; //amount of rabbits that died in current round
 
private Point location; //where the rabbit is located


public void draw(boolean isSame, SyncPoint[] points, Component page, Graphics davinci) {
//draws rabbit on screen tells weather or not to preserve current location 
//or make a new random one
 
int j = 0; //counter
boolean system = false; //flag
 
//find a random coordinate if nessecery
if(!isSame) { //start of if

while(true) { //start of infinite loop
int rndm = (int) (Math.random() * (points.length + 1));

//make sure that there are no rabbits already on those coordinates
//loops through 30 times then searches systematically
if(j == 30) {
system = true;
break;
} //end of if

if(points[rndm].getIsSame = false) { //start of if
location = new Point(points[rndm]);
break;
} //end of if

++j;
} //end of infinite loop

//systematically find empty coordinate
if(system) { //start of if
for (SyncPoint p : points) { //start of loop

if(!p.getIsSame) {//start of nested if
location = null;
location = new Point(p);
p.setIsSame = true;
break;
} //end of nested if
} //end of loop
if(location == null) {
System.out.println("array full, rabbit dead, overpopulation");
totalPop = totalPop - 1;
return;
} //end of if
} //end of if
} //end of if
 
//draw image
photo.paintIcon(page, davinci, location.getX(), location.getY());
 
} //end of draw
 
public void die() {
//kills rabbit, erases image, and removes from total number of rabbits alive
 
//subtracts one from the number of rabbits alive
--totalPop;
++rabbitsDead;
 
//sets refrence to null

} //end of die
 
public void die(ArrayList<Rabbit> Rabbits) { //overloaded method for arraylists
//same as above but removes from ArrayList

++rabbitsDead;
totalPop = totalPop - 1;
Rabbits.remove(this);
} //end method
 
public Rabbit() { //constructer for rabbit class
//makes a rabbit
 
//sets the image to what it should be
photo = new ShapeIcon(Rabbit.class.getResource("/image/rabbit.gif"));
 
//adds one to total rabbits
++totalPop;
 

} //end of constructer rabbit
 
public void reproduce(ArrayList<Rabbit> rabbits) {
// a shortcut for doubling rabbit population with an arraylist
 
//add a new rabbit to an ArrayList
rabbits.add(new Rabbit());
 
//adds one to total amount of rabbits alive
++totalPop;
 
} //end of reproduce
 

public static void reset() {
//sets variables to zero


//set static variables to zero
rabbitsDead = 0;
 
} //end of reset

//////////////////////////////////////////below is encapulation code////////////////////////
 
public Point getPoint() {
return location;
}

} //end of class Rabbit
  

and here is the error messages

   Rabbit.java:44: cannot find symbol
symbol  : class ShapeIcon
location: class com.googlepages.kpcode.LynxVsRabbit.Rabbit
        private ShapeIcon photo; //picture to use
                ^
Rabbit.java:53: cannot find symbol
symbol  : class SyncPoint
location: class com.googlepages.kpcode.LynxVsRabbit.Rabbit
                public void draw(boolean isSame, SyncPoint[] points, Component p
age, Graphics davinci) {
                                                 ^
Rabbit.java:83: cannot find symbol
symbol  : class SyncPoint
location: class com.googlepages.kpcode.LynxVsRabbit.Rabbit
                                        for (SyncPoint p : points) { //start of
loop
                                             ^
Rabbit.java:128: cannot find symbol
symbol  : class ShapeIcon
location: class com.googlepages.kpcode.LynxVsRabbit.Rabbit
                                photo = new ShapeIcon(Rabbit.class.getResource("
/image/rabbit.gif"));
                                            ^
4 errors
 

[ March 30, 2008: Message edited by: colton peterson ]

[marc weber]

Ref: JLS - 7 Packages...

A package consists of a number of compilation units (�7.3). A compilation unit automatically has access to all types declared in its package and also automatically imports all of the public types declared in the predefined package java.lang.

[marc weber]

Originally posted by colton peterson:
... I have checked the classpath...

What is your classpath set to? Which directory are you compiling from?

ShapeIcon and SyncPoint are both declared to be in the package com.googlepages.kpcode.LynxVsRabbit, right?
[ March 30, 2008: Message edited by: marc weber ]

[colton peterson]

actually I explicitly set it when I compiled I think I still have it somewhere in my command prompt . . .

 C:\Documents and Settings\Kolten\Desktop\lynx vs rabbits\source\com\googlepages\
kpcode\LynxVsRabbit>javac -d "C:\Documents and Settings\Kolten\Desktop\lynx vs r
abbits\class" [B]-cp "C:\Documents and Settings\Kolten\Desktop\lynx vs rabbits\sour
ce\com\googlepages\kpcode\LynxVsRabbits"[/B] Rabbit.java   

[colton peterson]

thanks. I got some more errors but they are different than before. Back to debugging!

[marc weber]

In Java, classes are identified by their qualified names. Because ShapeIcon is in the package com.googlepages.kpcode.LynxVsRabbit, its qualified name is com.googlepages.kpcode.LynxVsRabbit.ShapeIcon, and this is found in the directory C:\Documents and Settings\Kolten\Desktop\lynx vs rabbits\class. Use that as your classpath, and it should work.