Java has a dup2_x2 instruction which, according to the documentation, has the following behavior: Duplicate the top one or two values on the operand stack and insert the duplicated values, in the original order, into the operand stack. Does javac produce bytecode with this instruction? What are its potential …
Tag: javac
How to get from parse tree to Java class file
I am working on a command-line tool with the following functionality: Parse modified .java files using an extended ANTLR4 Java9 grammar. The syntax in the files is Java, with one modification to the method declaration which includes a purpose, like in this example: public void {marketing} sendEmail() {} Colle…
IntelliJ 2021.2.2 gives error ‘java: error: invalid source release: 18’ when compiling program
I’ve looked trough many answers here on so but haven’t found anything helpful. I am using java version 16.0.1 My program doesn’t use maven or gradle. The program worked fine until I updated my ij earlier today. Full error: Here are the files from .idea and the .iml file: https://1drv.ms/u/s!…
Java compiler wrongly marks varible as might already have been assigned to
For some reason java compiler marks the lower str variable as “might already have been assigned to” although this scenario is not possible (at least so I think). any idea why? I know removing the final modifier will solve it but I would like to understand the reason… using java 15 on intelli…
Antlr4 Project Directory Structure Issue
I’m trying to set up an Antlr4 project using Java’s package directory structure. The top level directory contains PondParser.g4, PondLexer.g4, and build_script. build_script is expected to build and run the antlr4 test rig Relevant PondParser.g4 header and options: Relevant PondLexer.g4 header and…
Ant Javac compile subpackage class files to the parent src directory
I would like Ant 1.9 to be able to compile servlet classes to the parent src directory, but the file system has the files in packages. No, the packages are not declared in the servlet files. The code is deployed with all the servlets in the same directory. I supposed I can create an ant copy command to do thi…
Javac – plugin not found
I am trying to make my own Javac plugin but things aren’t going so well already 🙁 I am following this tutorial: https://www.baeldung.com/java-build-compiler-plugin and when I want to test the first …
find the compiled class version number
My project consists of some third party jar files, which was compiled in different version of java. My project is using older version of java so i am getting UnsupportedClassVersionError while executing the application. Is there any other way to get the version of java/jre number[45..51] in which the class fi…
Android: javac vs Dalvik
My understanding is that Google didn’t like Oracle’s licensing policy for using the JRE in Java ME so it just rewrote it using its own JVM specification that mimics the JRE but behaves a little bit differently, especially when it comes to making things more efficient and more secure. So, if my und…
javac error: Class names are only accepted if annotation processing is explicitly requested
I get this error when I compile my java program: Here is the java code (I’m running this on Ubuntu). Here is the javac command: How do I compile this program? Answer You at least need to add the .java extension to the file name in this line: From the official faq: Class names, ‘HelloWorldApp’…