• Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

KATHY SCJP 1.6 : THREADS, exercise 9-2. Is my code fine?

 
Rahul Sudip Bose
Ranch Hand
Posts: 637
Eclipse IDE Firefox Browser Java
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
New to threads. I am not sure if my solution is the simplest/correct. It compiles and runs. If there is a better/neater way to do this, please let me know.

Here is the question, page 738 :

In this exercise we will attempt to synchronize a block of code. Within that block of code we will get the lock on an object, so that other threads cannot modify it while the block of code is executing. We will be creating three threads that will all attempt to manipulate the same object. Each thread will output a single letter 100 times, and then increment that letter by one. The object we will be using is StringBuffer. We could synchronize on a String object, but strings cannot be modified once they are created, so we would not be able to increment the letter without generating a new String object. The final output should have 100 As, 100 Bs, and 100 Cs all in unbroken lines.

INSTEAD OF 100, I CHOOSE 5.

Here is my code :


sample outputs :

 
Ankit Garg
Sheriff
Posts: 9528
33
Android Google Web Toolkit Hibernate IntelliJ IDE Java Spring
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Your code is achieving the desired output but its not correct. You need to synchronize an instance method. Basically you need to get a lock on the object which is being manipulated. How about moving the modifyStringBuff method to Job class (without any parameters) and making it an instance method...
 
Jatin Dhingra
Greenhorn
Posts: 29
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Also its good practice to keep Thread and Thread job as two different classes..to be more OO specific. Although it doesnt effect functionality anyhow but just increases readability.
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic