Eclipse doesn't recognize 'default' keyword

Question

I am trying to make a simple Interpreter for Java. Out teacher gave us a code to modify to reach our goal, but Eclipse doesn't like the keyword 'default'

The error is "Syntax error on token "default", delete this token"

I think it depends from my JDK version of java, this is what i am using

What should i modify?

Edit: i have Java 8 installed, but Eclipse doesn't allow me to change my compilance level over 1.7

*"i have Java 8 installed, but Eclipse doesn't allow me to change my compilance level over 1.7"* - Because that not Java 8. A directory called "Java 8" doesn't mean that Java 8 is actually inside. Check what `[path to java]/jre/bin/java -version` is telling you. — Tom, Jun 25 '17 at 11:38
stefano@berti-casa:/usr/lib/jvm/java-8-oracle/bin$ ./java -version java version "1.8.0_131" Java(TM) SE Runtime Environment (build 1.8.0_131-b11) Java HotSpot(TM) Server VM (build 25.131-b11, mixed mode) I think this is Java 8, but i am not sure i am using this in Eclipse, how can i check it? — Stefano Berti, Jun 25 '17 at 11:51
So i am using the right version of JRE, the problem could be the JDK? — Stefano Berti, Jun 25 '17 at 11:58
What release of Eclipse is this? You need Luna (4.4), Mars (4.5) or Neon (4.6) to support Java 8. — greg-449, Jun 25 '17 at 15:11

score 0 · Answer 1 · answered Jun 25 '17 at 11:17

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Interface Default Methods introdced only in Java 8

Download jdk 8 and use it in Eclipse

Download

answered Jun 25 '17 at 11:17

Ori Marko

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score 0 · Answer 2 · answered Jun 25 '17 at 11:18

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This is because you are using JRE JavaSE-1.7:

This JRE isis prior to Java 8, where default keyword has been introduced for defining default implementations of interface methods.

Switch JRE version to 1.8 to fix this problem.

answered Jun 25 '17 at 11:18

Sergey Kalinichenko

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@StefanoBerti Did you follow directions at the link on how to switch JDK? – Sergey Kalinichenko Jun 25 '17 at 11:38
Yes, but in the options for the Compiler Compilance Level i have just 1.3, 1.4, 1.5, 1.6, 1.7, there isn't 1.8 – Stefano Berti Jun 25 '17 at 11:43
@StefanoBerti Does the portion of screen on your second screen shot shows 1.8 now? There is a link to Eclipse inside the accepted answer that I linked above, you need to follow it to change JRE. – Sergey Kalinichenko Jun 25 '17 at 11:50

score 0 · Answer 3 · answered Jun 25 '17 at 11:23

Basically you just can not use/define an default method, because those are available since java 8 (and your project is using java7)... so you need to move the project to java8.

Oracle can help you, check this here

http://www.oracle.com/technetwork/java/javase/8-whats-new-2157071.html

is the What's New in JDK 8 part, 3rd element in the list....

Default methods enable new functionality to be added to the interfaces of libraries and ensure binary compatibility with code written for older versions of those interfaces.

Eclipse doesn't recognize 'default' keyword

3 Answers3