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Java Class Constructor Question

Started by Matthew Melendez Feb 2, 2012 at 8:36 PM 3 replies 1.3k views

Original Post

Feb 2, 2012 at 8:36 PM

Can anyone find any problems that make arise with this code?
Will there be a problem with an empty constructor like this?

package foo;
 
 
 import java.awt.Image.*;
 import java.awt.image.BufferedImage;
 public class foo
 {
 BufferedImage image = new BufferedImage(64,32,BufferedImage.TYPE_INT_ARGB);
 
 
 public foo()
 {
 //no code here
 }
 public void setRgb(int x, int y, int rgb)
 {
 image.setRGB(x,y,rgb);
 }
 }

I want to be able to create a new foo object like so:


 foo object = new foo();

and be able to do this:


 object.setRgb(5,5,0x00000000)

Florian22222

Feb 2, 2012 at 8:56 PM

There won´t be an error. Although it´s not a good programming style.
The better way is to call the constructor of the image in your own constructor like this:


 package foo;
 
 import java.awt.Image.*;
 import java.awt.image.BufferedImage;
 public class foo
 {
 BufferedImage image;
 
 public foo()
 {
 image = new BufferedImage(64,32,BufferedImage.TYPE_INT_ARGB)
 }
 public void setRgb(int x, int y, int rgb)
 {
 image.setRGB(x,y,rgb);
 }
 }

Hope I could help you!

Matthew Melendez

Author

Matthew Melendez

Feb 2, 2012 at 9:20 PM

There won´t be an error. Although it´s not a good programming style.
The better way is to call the constructor of the image in your own constructor like this:
package foo; import java.awt.Image.*; import java.awt.image.BufferedImage; public class foo { BufferedImage image; public foo() { image = new BufferedImage(64,32,BufferedImage.TYPE_INT_ARGB) } public void setRgb(int x, int y, int rgb) { image.setRGB(x,y,rgb); } }

Hope I could help you!

I tired that and the setRgb() method can't find the image object. I think it might be out of scope of the setRgb() method.

WavyVirus

Feb 2, 2012 at 10:44 PM

I haven't used the AWT classes, but in general the setRgb method should be able to use the image object. Can you post any error message which is generated?

rip-off

Mod

445

rip-off

Feb 2, 2012 at 11:53 PM

The better way is to call the constructor of the image in your own constructor like this:
[/quote]
It is about the same. This is stylistic really.

I tired that and the setRgb() method can't find the image object. I think it might be out of scope of the setRgb() method.
[/quote]
Did you leave "image" as a field or did you accidentally make it local to the constructor?

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