Storing classes in files

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Hello,
I am trying to do something very simple but my dial up connection is making it hard to research so I'd like some help! I'm trying to store instances of classes I created in a file. Something along these lines:

Java Syntax (Toggle Plain Text)
class apple
{
	int flavor;
	String color;
	apple(int a, String b)
	{
		flavor = a;
		color = b;
	}
}
 
//.....
 
	apple RedDelicious = new apple(10, "red");
	writeFile.write(RedDelicious);
class apple
{
	int flavor;
	String color;
	apple(int a, String b)
	{
		flavor = a;
		color = b;
	}
}

//.....

	apple RedDelicious = new apple(10, "red");
	writeFile.write(RedDelicious);

I know that there is some way to do this through serialization and I've also heard that something along the lines of FileOutputStream/FileInputStream will allow me to write/read the classes but I would appreciate a little guidance on their use in this context. I'm sorry to bother you guys but my dial up is hindering the research process! Thanks!

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dmanw100

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Posting Whiz in Training

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since Apr 2008

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May 24th, 2009

Re: Storing classes in files

Your class must implements a java.io.Serializable Interface and one more thing is that you have to use java.io.ObjectInputStream and java.io.ObjectOutputStream class to read and write objects respectively.

Java Syntax (Toggle Plain Text)
class apple implements java.io.Serializable
{
	int flavor;
	String color;
	apple(int a, String b)
	{
		flavor = a;
		color = b;
	}
}
 
//.....
 
	apple RedDelicious = new apple(10, "red");
                java.io.ObjectOutputStream os=new java.io.ObjectOutputStream(new java.io.FileOutputStream("data.txt"));
 
	os.writeObject(RedDelicious);
                os.flush();
class apple implements java.io.Serializable
{
	int flavor;
	String color;
	apple(int a, String b)
	{
		flavor = a;
		color = b;
	}
}

//.....
               
	apple RedDelicious = new apple(10, "red");
                java.io.ObjectOutputStream os=new java.io.ObjectOutputStream(new java.io.FileOutputStream("data.txt"));

	os.writeObject(RedDelicious);
                os.flush();

adatapost

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Posting Genius

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6,527 posts
since Oct 2008

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May 24th, 2009

Re: Storing classes in files

Thanks for reminding me. It's been awhile since I tried it and one can only research on dial up can only go so long until the patience runs out ha!

dmanw100

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Solved Threads: 27

Posting Whiz in Training

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since Apr 2008

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