AutoCAD WS 1 6 1 Released – AutoCAD Utility Design Now Supported

Autodesk released the latest version of AutoCAD WS (mobile version 1.6.1) for the web based version as well as the iOS and Android versions.  All versions are up to date and match each other.  These latest versions support AutoCAD Utility Design drawings.  According to the Google Play Store and Apple App Store, various bug fixes are also addresses.

See the AutoCAD WS blog post here about this update.

 

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Why use PreparedStatement in Java JDBC – Example Tutorial

PreparedStatement in Java is one of several ways to execute SQL queries using JDBC API. Java provides Statement,

PreparedStatement and CallableStatement for executing queries. Out of these three, Statement is used for general purpose queries, PreparedStatement is used for executing parametric query and CallableStatement is used for executing Stored Procedures. PreparedStatement is also a popular topic in java interviews. Questions like Difference between Statement and PreparedStatement in Java and How to prevent SQL Injection attacks in Java are popular java interview questions. In this Java JDBC tutorial we will see why should you use use PreparedStatement in Java, What are the major advantages of using PreparedStatement in Java and how PreparedStatement prevents SQL Injection attacks in Java.

This article is in continuation of my earlier post on database and java like 4 tips to improve performance of Java application with database and Difference between truncate and delete in SQL.If you haven’t read  them already you may found  those tutorial useful and interesting.

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HashSet in Java – 10 Examples Programs Tutorial

HashSet in Java is a collection which implements Set interface and backed by an HashMap. Since HashSet uses HashMap internally it provides constant time performance for operations like add, remove, contains and size give HashMap has distributed elements properly among the buckets. Java HashSet does not guarantee any insertion orders of the set but it allows null elements. HashSet can be used in place of ArrayList to store the object if you require no duplicate and don't care about insertion order. Iterator of HashSet is fail-fast and throws ConcurrentModificationException if HashSet instance is modified concurrently during iteration by using any method other than remove() method of iterator class.If you want to keep insertion order by using HashSet than consider using LinkedHashSet. It is also a very important part of any Java collection interview, In short correct understanding of HashSet is must for any Java developer.

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What is Race Condition in multithreading – 2 Examples in Java

Race condition in Java is a type of concurrency bug or issue which is introduced in your program because  parallel execution of your program by multiple threads at same time, Since Java is a multi-threaded programming language hence risk of Race condition is higher in Java which demands clear understanding of what causes a race condition and how to avoid that. Anyway Race conditions are just one of hazards or risk presented by  use of multi-threading in Java just like deadlock in Java. Race conditions occurs when two thread operate on same object without proper synchronization and there operation interleaves on each other. Classical example of Race condition is incrementing a counter since increment is not an atomic operation and can be further divided into three steps like read, update and write. if two threads tries to increment count at same time and if they read same value because of interleaving of read operation of one thread to update operation of another thread, one count will be lost when one thread overwrite increment done by other thread. atomic operations are not subject to race conditions because those operation cannot be interleaved. This is also a popular multi-threading interview questions during core java interviews. In this article we will see how to find race condition in Java and  two sample code patterns which often causes race conditions in Java.

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