22 Aug Lecture Note

import java.io.*;
 
class Writer1 {
public static void main(String[]args) {
	try { 
			boolean newFile = false;
			File file = new File("filewrite1.txt"); // it's only an object
			System.out.println(file.exists()); 
			newFile = file.createNewFile(); // maybe create a file!
			System.out.println(newFile); // already there?
			System.out.println(file.exists()); // look again
		}
	} catch(IOException e) { }
}
}

This Java code is all about creating a text file called “filewrite1.txt”. Let’s break it down:

1. Import Statement:

• import java.io.*; This line brings in the necessary tools for working with files, like File and IOException.

2. The Writer1 Class:

• class Writer1 { ... } This defines a class called Writer1, where our code will live.

3. The main Method:

• public static void main(String[] args) { ... } This is the starting point of the program. It’s where the code execution begins.

4. Handling File Operations:

• try { ... } catch(IOException e) { } : This is a safety net to handle any problems that might happen when working with files.
• boolean newFile = false; : Creates a variable to track if we’ve created a new file.
• File file = new File("filewrite1.txt"); : This creates an object representing a file named “filewrite1.txt”. It doesn’t actually create the file yet, just a way to refer to it.
• System.out.println(file.exists()); Checks if the file already exists. It will print “true” if it does, and “false” if it doesn’t.
• newFile = file.createNewFile(); This is where the file creation happens. It returns true if a new file is created, and false if it already existed.
• System.out.println(newFile); Prints whether a new file was created.
• System.out.println(file.exists()); Checks again to see if the file exists (it should now).

In Summary:

This code tries to create a file called “filewrite1.txt”. It checks if the file already exists before attempting to create it. If the file is successfully created, it will print “true” for both newFile and file.exists(). If the file already existed, it will print “false” for newFile and “true” for file.exists().

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Paper Structure

• 40 MCQs
• Structured : giving incomplete questions to fill the rest (just to fill the blanks)
• Java DataBase Connectivity (JDBC) not included in final exam