In IntelliJ IDEA: In File Menu → Project Structure → Project, change Project Language Level to 8.0 – Lambdas, type annotations etc. For Android 3.0+ Go File → Project Structure → Module → app and In Properties Tab set Source Compatibility and Target Compatibility to 1.8 (Java 8) Screenshot:
Restarting intelliJ did not help, restarting machine did!
It means: “A class that you use needs another class that is not on the classpath.” You should make sure (as Harry Joy suggests) to add the required jar to the classpath.
Go to File > Settings > Build, Execution, Deployment > Compiler > Java Compiler If on a Mac, it’s under Intellij IDEA > Preferences… > Build, Execution, Deployment > Java Compiler Change Target bytecode version to 1.8 of the module that you are working for. If you are using Maven Add the compiler plugin to pom.xml under the top-level project node: (Hoisted from the comments.) Note: … Read more
The reason you’re getting this error is because you didn’t save the class into a file called Hello.java (case-sensitive!)
See https://stackoverflow.com/a/12900859/104891. First of all, set the language level/release versions in pom.xml like that: Maven sets the default to 1.5 otherwise. You will also need to include the maven-compiler-plugin if you haven’t already: Also, try to change the Java version in each of these places: File -> Project structure -> Project -> Project SDK -> 11. File -> Project structure -> Project … Read more
What are iml files in Android Studio project? A Google search on iml file turns up: IML is a module file created by IntelliJ IDEA, an IDE used to develop Java applications. It stores information about a development module, which may be a Java, Plugin, Android, or Maven component; saves the module paths, dependencies, and other settings. … Read more
Judging from the directory structure, you have two packages client and server, but the code expects packages badugi.client and badugi.server. Here is a way to fix it: Position your cursor to the underlined package statement (package badugi.server) Hit ALT + ENTER Select option Move to package badugi.server. This will automatically fix your directory structure to match the declared package … Read more
That’s part of the syntax of the new lambda expressions, to be introduced in Java 8. There are a couple of online tutorials to get the hang of it, here’s a link to one. Basically, the -> separates the parameters (left-side) from the implementation (right side). The general syntax for using lambda expressions is (Parameters) -> { Body } where … Read more
If you see that error occur after upgrading versions of IntelliJ IDEA or Android Studio, or after Generating a new APK, you may need to refresh the IDE’s cache.