// call this method to write the description to the file
// the file pointer must be already positioned
// the description must have been set
private void writeDescription() throws IOException {
if (description.length() > DESCRIPTION_LENGTH)
description = description.substring(0, DESCRIPTION_LENGTH);
outStream.writeChars(description);
for (int j = 0; j < (DESCRIPTION_LENGTH - description.length()); j++) outStream.writeChar(' ');
}
/**
* Writes the Item location to the Items Random Access File
*
* @param file - the Item's Random Access File
*/
private void writeLocationToFile(RandomAccessFile file) {
try {
file.writeByte(1); // Write the warehouse number
file.writeByte(getLocation().getAisle()); // Write the aisle number
file.writeByte(getLocation().getColumn()); // Write the column number
file.writeChar(getLocation().getRow()); // Write the row number
} catch (Exception e) {
}
}
// call this method to write the column names to the file
// the file pointer must be already positioned
private void writeColumnNames(ArrayList names) throws IOException {
String column;
for (int i = 0, numCols = names.size(); i < numCols; i++) {
column = (String) names.get(i);
if (column.length() > COLUMN_LENGTH) column = column.substring(0, COLUMN_LENGTH);
outStream.writeChars(column);
for (int j = 0; j < (COLUMN_LENGTH - column.length()); j++) outStream.writeChar(' ');
}
}
public static void main(String args[]) {
try {
String fname = "d:\\q.txt";
String mode;
// mode = "r";//r : file must exist
mode = "rw"; // rw : file will be created or opened
// open the file
RandomAccessFile raf = new RandomAccessFile(fname, mode);
/*
//seek and write demo
raf.seek(10);//position file r/w pointer at index 10 wrt BOF
//a seek beyond file size causes file to grow upto the seek value
raf.write(65);//raf.write('A');
*/
// r/w java datatypes
int i1, i2;
float f1, f2;
char c1, c2;
String s1, s2;
i1 = -10;
f1 = 1234.5678F;
c1 = 'q';
s1 = "hello files";
raf.seek(0); // reach BOF
raf.writeInt(i1);
raf.writeFloat(f1);
raf.writeChar(c1);
raf.writeUTF(s1);
raf.seek(0); // reach BOF
i2 = raf.readInt();
f2 = raf.readFloat();
c2 = raf.readChar();
s2 = raf.readUTF();
System.out.println(i2);
System.out.println(f2);
System.out.println(c2);
System.out.println(s2);
// close the file
raf.close();
} catch (IOException ex) {
System.out.println(ex); // ex converts into ex.toString()
}
} // main