Java Keyboard Input For Day 16 Of Javatober

Image courtesy of pexels.com

I have been using CodeGym now for a few days and I think it is good, but at times I feel it is going overboard with the repetition. The past few days have seen me doing a lot of work with input and output streams but due to the exercises I have been working on, I feel like I have almost forgot some of the word we did earlier in the week.

What Did I Learn Today

We have been working a lot on System.out but today I finially got to work with System.in to gather input from the users keyboard. If you move ahead to the code we are describing, you will see its a lot more complex than the usually System.out.println() statement. You see we are using the line:

BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

Yep, it looks pretty complicated but what is everything doing here, so we can start from the end bit which is "System.in". We need to remember there are two types of streams: Input streams are used to receive data and Output streams are for sending data. In Java, these streams are implemented by the InputStream and OutputStream classes where System.in is an InputStream object. System.out is a stream for sending data to the console, while System.in is for getting data from the keyboard.

We then need to create an InputStreamReader object and pass it an input stream that it will read data from. This is where we have:

new InputStreamReader(System.in)

In this case we use System.in to gather data from the keyboard, but we could use FileInputStream for reading from files and InputStreamReader knows how to read data and convert bytes into characters.

We then use the BufferedReader to read the inputed data, it uses a special area called a buffer to store the and access the data and allows BufferedReader + InputStreamReader to be faster than InputStreamReader alone.

Bufferedreader can read data not only one character at a time (though it can do this with its read() method), but also whole lines at a time! This is done using the readLine() method;

Code For The Day

  1 import java.io.*;
  2 
  3 public class Test {
  4     public static void main(String[] args) throws Exception {
  5         
  6         BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
  7         String name = reader.readLine();
  8 
  9         System.out.println(name + " is typing on the keybaord");
 10     }
 11 }

Output

java Test
test
test is typing on the keybaord

I'll be posting daily, sharing my experiences on my “1 Month of Java Code” experiences”, my previous post on day 15 can be found below, so feel free to have a look:
https://steemit.com/java/@run.vince.run/in-depth-java-variables-for-day-15

If you have found this post useful or interesting, please consider Commenting, Upvoting, Following and/or Resteeming