Java / Design Patterns

How do you implement a thread-safe Singleton in Java?

There are multiple ways to write thread-safe singleton in Java.

using double checked locking,
by using static Singleton instance initialized during class loading.
using Java enum to create a thread-safe singleton class.

Using Java enum to create thread-safe singleton is the most simplest way.

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OOPS Concepts and its implementation in Java 19 Inheritance 29 JDK, JRE, JVM, JIT 69 Java Identifiers 4 Object, Class and Package 44 Variable 9 Local Variables 6 Instance Variables (Non Static Variables) 3 Class Variables (Static Variables) 13 Package 10 Operators 9 Modifiers 29 Data types 10 Methods 39 Control Statements 14 Access Modifiers 5 Constructor 38 Interface 46 Abstract Class 19 Enum 20 Arrays 20 Strings 32 Using String 29 Exception 55 Collections 56 List and its implementations 22 Map and its implementations 39 Set and its implementations 23 Queue and its implementations 4 Regular expressions 3 Design Patterns 75 Generics 20 Casting 5 volatile 13 Java ThreadLocal 10 Java Multithreading 113 Java Multithreading part II 18 final keyword 13 static keyword 16 Java Transactions (JTA) 21 Concurrent collections 55 Java Serialization 36 JDBC 53 JNDI 17 RMI 6 JAXB 10 JMS 45 JMX 9 Servlet Interview Questions 16 log4j 19 Annotations 10 XML 14 Garbage collection 31 Programs 8 JVM 4 Java8 streams 34 JavaFX 6 Autosys Interview questions 21 The Java Virtual Machine: How and What Is It Used For? Java 11 10 Java 12 5 Top Errors You Should Avoid when Studying Programming Java 17 1 JPMS 6 Java Record Keyword 4 MapStruct Java Interview questions Java 21 Interview Questions 46 Lombok Interview questions 48 Quarkus Interview questions 50

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