DZone
Thanks for visiting DZone today,
Edit Profile
  • Manage Email Subscriptions
  • How to Post to DZone
  • Article Submission Guidelines
Sign Out View Profile
  • Post an Article
  • Manage My Drafts
Over 2 million developers have joined DZone.
Log In / Join
Refcards Trend Reports Events Over 2 million developers have joined DZone. Join Today! Thanks for visiting DZone today,
Edit Profile Manage Email Subscriptions Moderation Admin Console How to Post to DZone Article Submission Guidelines
View Profile
Sign Out
Refcards
Trend Reports
Events
Zones
Culture and Methodologies Agile Career Development Methodologies Team Management
Data Engineering AI/ML Big Data Data Databases IoT
Software Design and Architecture Cloud Architecture Containers Integration Microservices Performance Security
Coding Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks
Partner Zones AWS Cloud
by AWS Developer Relations
Culture and Methodologies
Agile Career Development Methodologies Team Management
Data Engineering
AI/ML Big Data Data Databases IoT
Software Design and Architecture
Cloud Architecture Containers Integration Microservices Performance Security
Coding
Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance
Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks
Partner Zones
AWS Cloud
by AWS Developer Relations
Securing Your Software Supply Chain with JFrog and Azure
Register Today

Trending

  • Understanding Dependencies...Visually!
  • How To Approach Java, Databases, and SQL [Video]
  • Microservices With Apache Camel and Quarkus (Part 2)
  • Health Check Response Format for HTTP APIs

Trending

  • Understanding Dependencies...Visually!
  • How To Approach Java, Databases, and SQL [Video]
  • Microservices With Apache Camel and Quarkus (Part 2)
  • Health Check Response Format for HTTP APIs
  1. DZone
  2. Coding
  3. Languages
  4. Java 8/9 Best Practices — Part-1 (Static Factory Methods)

Java 8/9 Best Practices — Part-1 (Static Factory Methods)

Nitesh Gupta user avatar by
Nitesh Gupta
·
Updated Jul. 23, 20 · Opinion
Like (5)
Save
Tweet
Share
7.04K Views

Join the DZone community and get the full member experience.

Join For Free

Should Consider Static Factory Methods for Creating Objects

There are various ways to create the objects in java, In a traditional way for the class to allow a client to create an instance is to provide the public default constructor. However, there is another way to create an instance of the Class. A class can provide a static public method which is a static method that returns the instance of the class. Let's see the example

Java
 




x


 
1
public static Boolean valueOf(boolean a){
2
  return a ? Boolean.TRUE : Boolean.FALSE;
3
}



There are various advantages and disadvantages to consider Static Methods -

Advantages

  1. Static Methods have a name
  2. Not required to create an object every time it gets invoked
  3. They can return an object of any subtype of their return type
  4. Class of the returned object can vary from call to call as a function of the input parameters
  5. Class of the returned object need not exist when the class containing the method is written

Limitations

  1. A class without public or protected constructor can not be sub-classed if we only expose static Method for object creation
  2. It could be difficult for the programmer to find the method where the object is being created unlike a constructor

Some common names for static factory methods

Java
 




xxxxxxxxxx
1


 
1
Date d = Date.from (instance); //from
2
Set<Status> statuses = EnumSet.of(INITIATED, INPROGRESS,COMPLETED);//Use of Of
3
String str1 = String.valueOf(Integer.MAX_VALUE); // use of valueOf
4
Object newArray = Array.newInstance(classObject, length) // use of newInstance
5
BufferedReader br = Files.newBufferedReader(path);//use of newType
6

          



Both Static factory methods and public constructors both have their users. Static factories are preferable, so avoid the defining public constructor and think if Static factories can be used.

Ref - Effective Java - Third Edition by Joshua Bloch

Factory (object-oriented programming) Java (programming language) Object (computer science)

Published at DZone with permission of Nitesh Gupta. See the original article here.

Opinions expressed by DZone contributors are their own.

Trending

  • Understanding Dependencies...Visually!
  • How To Approach Java, Databases, and SQL [Video]
  • Microservices With Apache Camel and Quarkus (Part 2)
  • Health Check Response Format for HTTP APIs

Comments

Partner Resources

X

ABOUT US

  • About DZone
  • Send feedback
  • Careers
  • Sitemap

ADVERTISE

  • Advertise with DZone

CONTRIBUTE ON DZONE

  • Article Submission Guidelines
  • Become a Contributor
  • Visit the Writers' Zone

LEGAL

  • Terms of Service
  • Privacy Policy

CONTACT US

  • 600 Park Offices Drive
  • Suite 300
  • Durham, NC 27709
  • support@dzone.com

Let's be friends: