Java <identifier> expected with writeObject()

Question

For a class assignment, I'm required to write an object to a file. Our professor gave us a section of code to complete this, but apparently it's wrong because I'm getting an error. Here's my code.

class InvMaintenance {

    //create an OutputStream to write data to a file
    FileOutputStream fos = new FileOutputStream(inven.dat);
    BufferedOutputStream bos = new BufferedOutputStream(fos);
    ObjectOutputStream oos = new ObjectOutputStream(bos);

    final long MAX_SIZE = 100; //constant for array length
    Inventory cInventory = new Inventory(MAX_SIZE); //instantiate Inventory object
    oos.writeObject(cInventory); //write initial Inventory to file  
    public static void main(String[] args) {
        //Output options
        /*  Inventory Maintenance
            1) Add Item
            2) Remove Item
            3) Sell Item
            4) Receive Item
            5) Display Inventory
            6) Quit
            Please Select NUMBER: */

        //switch on options
        //call appropriate method

        oos.writeObject(cInventory);
        oos.close();
    }
}

My error is occuring on the line oos.writeObject(cInventory);

Item.java:150: <identifier> expected
    oos.writeObject(cInventory);            //write initial Inventory to file   
                   ^
Item.java:150: <identifier> expected
    oos.writeObject(cInventory);            //write initial Inventory to file   
                              ^
2 errors

And yes, for some reason it's saying this is two separate errors that are... exactly the same.

Any help debugging would be appreciated. What's wrong?

rauschen · Accepted Answer · 2012-01-22 10:07:39Z

2

that had to be in the main-method

//create an OutputStream to write data to a file
FileOutputStream fos = new FileOutputStream(inven.dat);
BufferedOutputStream bos = new BufferedOutputStream(fos);
ObjectOutputStream oos = new ObjectOutputStream(bos);

Inventory cInventory = new Inventory(MAX_SIZE); //instantiate Inventory object

changed Code:

class InvMaintenance {

    final static long MAX_SIZE = 100;          //constant for array length

    public static void main(String[] args)
    {
        //Output options
            /*  Inventory Maintenance
                1) Add Item
                2) Remove Item
                3) Sell Item
                4) Receive Item
                5) Display Inventory
                6) Quit
                Please Select NUMBER: */

        //switch on options
        //call appropriate method

        //create an OutputStream to write data to a file
        FileOutputStream fos = new FileOutputStream(inven.dat);
        BufferedOutputStream bos = new BufferedOutputStream(fos);
        ObjectOutputStream oos = new ObjectOutputStream(bos);

        Inventory cInventory = new Inventory(MAX_SIZE); //instantiate Inventory object

        oos.writeObject(cInventory);
        oos.close();
    }   

}

Hint: change the constant to final static long .. it you use static the values is copied on compile time

Hint2: take care of the exceptions ..

edited Jan 22, 2012 at 10:07

answered Jan 22, 2012 at 9:59

rauschen

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2 Comments

Alex Over a year ago

Thank you, this worked. I have a slew of other errors to contend with now, but the error in question appears to be resolved. The hints were especially helpful!

rauschen Over a year ago

take a look at this answer .. there are a lot of other useful hints

NPE · Accepted Answer · 2012-01-22 09:59:51Z

0

The compiler complains about the following line:

oos.writeObject(cInventory);            //write initial Inventory to file

You can't have freestanding code like this outside all methods. Move it into main().

Variable declarations that precede it (FileOutputStream fos ...) should probably also be moved into main(). They would compile as they are now, but would cause you problems later on.

answered Jan 22, 2012 at 9:59

NPE

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Comments

Robin · Accepted Answer · 2012-01-22 10:02:41Z

0

As documented in the javadoc of the writeObject method, it throws an IOException. So you should either catch the exception by setting the statement in a try-catch block, or let your main method throw the exception

Further, you are trying to access non-static fields from a static context which won't work either.

Last, your statement oos.writeObject(cInventory); outside your main method will not work either as you cannot have statements lying around in your class.

answered Jan 22, 2012 at 10:02

Robin

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Comments

Tudor · Accepted Answer · 2012-01-22 10:03:27Z

0

Executable code such as method calls must be inside either a method or possibly a static block, but in your case it belongs clearly inside the main method. Move the code there and it will work.

Furthermore, the main method is the program entry point. Unless the control flow has some way of going from inside the main method to the code you want to execute, nothing will happen anway.

answered Jan 22, 2012 at 10:03

Tudor

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Mark Bramnik · Accepted Answer · 2012-01-22 10:04:42Z

0

where you define the following code?

//create an OutputStream to write data to a file
FileOutputStream fos = new FileOutputStream(inven.dat);
BufferedOutputStream bos = new BufferedOutputStream(fos);
ObjectOutputStream oos = new ObjectOutputStream(bos);

final long MAX_SIZE = 100;          //constant for array length
Inventory cInventory = new Inventory(MAX_SIZE); //instantiate Inventory object

oos.writeObject(cInventory);            //write initial Inventory to file

you have your class, you have a "main method", but where goes the code? Additional thing: what it "inven.dat"

BTW, if you have compilation error, you can't really debug your code, because your code should be compiler beforehands...

answered Jan 22, 2012 at 10:04

Mark Bramnik

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