The following identifiers are contextual keywords, and are only restricted in some contexts:
"Java Platform, Standard Edition Java API Reference". https://docs.oracle.com/javase/specs/jls/se21/html/jls-3.html#jls-3.9
"Java Language Specification - Section 3.9: Keywords". The Java Language Specification. Oracle. 2018-08-21. Retrieved 2018-12-25. https://docs.oracle.com/javase/specs/jls/se11/html/jls-3.html#jls-3.9
"Treatment of underscores". JEP 302: Lambda Leftovers. https://openjdk.org/jeps/302#Treatment-of-underscores
"Java Language Keywords". The Java Tutorials. Sun Microsystems, Inc. Retrieved 2017-07-24. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/_keywords.html
"Primitive Data Types". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html
Flanagan 2005, p. 22. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Returning a Value from a Method". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html
Flanagan 2005, pp. 66–67. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"The switch Statement". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2014-12-18. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/switch.html
Flanagan 2005, pp. 46–48. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"The switch Statement". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2014-12-18. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/switch.html
Flanagan 2005, pp. 46–48. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"The while and do-while Statements". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html
Flanagan 2005, pp. 48–49. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Primitive Data Types". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html
Flanagan 2005, p. 22. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Returning a Value from a Method". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html
Flanagan 2005, pp. 66–67. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"The if-then and if-then-else Statements". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/if.html
Flanagan 2005, pp. 44–46. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Java Language Keywords". The Java Tutorials. Sun Microsystems, Inc. Retrieved 2017-07-24. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/_keywords.html
"Primitive Data Types". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html
Flanagan 2005, p. 22. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Returning a Value from a Method". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html
Flanagan 2005, pp. 66–67. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"The for Statement". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/for.html
Flanagan 2005, pp. 50–54. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"The for Statement". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/for.html
"The if-then and if-then-else Statements". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/if.html
Flanagan 2005, pp. 44–46. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Primitive Data Types". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html
Flanagan 2005, p. 22. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Returning a Value from a Method". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html
Flanagan 2005, pp. 66–67. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Primitive Data Types". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html
Flanagan 2005, p. 22. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Returning a Value from a Method". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html
Flanagan 2005, pp. 66–67. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
Flanagan 2005, pp. 66–67. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Controlling Access to Members of a Class". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html
"Controlling Access to Members of a Class". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html
"Controlling Access to Members of a Class". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html
"Primitive Data Types". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html
Flanagan 2005, p. 22. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Returning a Value from a Method". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html
Flanagan 2005, pp. 66–67. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Nested Classes (The Java™ Tutorials > Learning the Java Language > Classes and Objects)". https://docs.oracle.com/javase/tutorial/java/javaOO/nested.html
"The switch Statement". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2014-12-18. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/switch.html
Flanagan 2005, pp. 46–48. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
Flanagan 2005, pp. 66–67. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Java Object Serialization Specification version 1.5.0". Sun/Oracle. 2004. 1.5 Defining Serializable Fields for a Class. Retrieved 2010-09-16.[permanent dead link] http://download-llnw.oracle.com/javase/1.5.0/docs/guide/serialization/spec/serial-arch.html#6250
Grosso, William (November 21, 2001). "Java RMI: Serialization". ONJava. O'Reilly Media. Declaring serialPersistentFields. Retrieved 2010-09-16. http://onjava.com/pub/a/onjava/excerpt/JavaRMI_10/index.html?page=3
"Returning a Value from a Method". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html
"Java Volatile Keyword". http://tutorials.jenkov.com/java-concurrency/volatile.html
"The while and do-while Statements". The Java Tutorials. Sun Microsystems, Inc. February 14, 2008. Retrieved 2008-12-03. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html
Flanagan 2005, pp. 48–49. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Sealed Classes". docs.oracle.com. Oracle Corporation. Retrieved 2021-08-07. https://docs.oracle.com/en/java/javase/15/docs/specs/sealed-classes-jls.html#jls
"Sealed Classes". docs.oracle.com. Oracle Corporation. Retrieved 2021-08-07. https://docs.oracle.com/en/java/javase/15/docs/specs/sealed-classes-jls.html#jls
"Sealed Classes". docs.oracle.com. Oracle Corporation. Retrieved 2021-08-07. https://docs.oracle.com/en/java/javase/15/docs/specs/sealed-classes-jls.html#jls
"Chapter 3. Lexical Structure". docs.oracle.com. Retrieved 2018-12-25. https://docs.oracle.com/javase/specs/jls/se11/html/jls-3.html#jls-3.9
"Chapter 14. Blocks, Statements, and Patterns". https://docs.oracle.com/javase/specs/jls/se21/html/jls-14.html#jls-14.11.1
"Switch Expressions". docs.oracle.com. Oracle Corporation. Retrieved 2020-12-27. https://docs.oracle.com/en/java/javase/16/language/switch-expressions.html
"Java Language Specification - Section 3.9: Keywords". The Java Language Specification. Oracle. 2018-08-21. Retrieved 2018-12-25. https://docs.oracle.com/javase/specs/jls/se11/html/jls-3.html#jls-3.9
Flanagan 2005, p. 20. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Java Language Specification - Section 3.9: Keywords". The Java Language Specification. Oracle. 2018-08-21. Retrieved 2018-12-25. https://docs.oracle.com/javase/specs/jls/se11/html/jls-3.html#jls-3.9
Flanagan 2005, p. 20. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan
"Java Language Keywords". The Java Tutorials. Sun Microsystems, Inc. Retrieved 2017-07-24. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/_keywords.html
"JEP 306: Restore Always-Strict Floating-Point Semantics". https://openjdk.java.net/jeps/306
Flanagan 2005, pp. 66–67. - Flanagan, David (March 2005). Java in a Nutshell (Fifth ed.). O'Reilly Media. ISBN 978-0-596-00773-7. Retrieved 2010-03-03. https://archive.org/details/javainnutshell00flan