Help needed

d6

i have this class to ecapsulate a worker and i want help creating a binary file in the main program using this class, not to sure how to combine the two


class Worker {
private String name;
private double wage;

Worker() {
}

Worker(String s, double w) {
name = s; wage = w;
}

void put(DataOutputStream dos) {
// write name & age attributes to dos (at file pointer)
try {

dos.writeUTF(name);
dos.writeDouble(wage);
} catch (IOException e) {
}
}

void get(DataInputStream dis) {
// read name & age attributes from file dis
try {

dis.readUTF();
dis.readDouble();
} catch (IOException e) {
}
}

void put(){ // display on screen
System.out.println(name + " " + wage);
}
}

ronivek

Not entirely sure what it is you're trying to accomplish or what constraints you're working with; but I've included a small snippet of code below that demonstrates the general idea.

All it does is effectively wrap a Data*Stream object around a Stream object; which in this case is a File*Stream object as it's a file you wish to work with.

String fileName = "c:\\file.txt";
try {      
    DataInputStream inputStream = new DataInputStream(new FileInputStream(fileName));
    DataOutputStream outputStream = new DataOutputStream(new FileOutputStream(fileName));
            
    worker.put(outputStream);
    worker.get(inputStream);            
} catch (IOException e) { e.printStackTrace(); }

marco_polo

You must love typing I can go whole line shorter ronvick :P

fileName = "c:\\file.txt"
try {      
    RandomAccessFile raf = new RandomAccessFile(fileName,"rw");

            
    worker.put(raf);
    worker.get(raf);            
} catch (IOException e) { e.printStackTrace(); }

ronivek

I don't think your code will even compile!

The whole point of my example was to illustrate the use of Streams; although I probably didn't do such a good job.

DublinDilbert

You will need to make sure your object is serialisable, from memory it must implement the serialisable interface.

Once your object is serialisable you can write it to an object stream.

So all your main program needs to do is open up a file, initalise an object stream, with the newly opened file. Then you can write your user defined objects to the object stream, hence they get stored to the file on the disk.