ECLIPSE JAVA 17 HOW TO
ECLIPSE JAVA 17 UPDATE

This can be particularly useful to pinpoint which version is in use when multiple JREs are installed on the same machine. Executing the commands echo %JAVA_HOME% and java -version inside a terminal should point to the existing Java installation directory and its version number.

ECLIPSE JAVA 17 UPDATE

The most straightforward solution is to update the JRE on the machine on which the code is running. This version of the Java Runtime only recognizes class file versions up to 52.0įigure 2: UnsupportedClassVersionError example Has been compiled by a more recent version of the Java Runtime (class file version 61.0), Exception in thread 'main' : com/rollbar/ExampleApp UnsupportedClassVersionError Error Exampleīelow is an example of the UnsupportedClassVersionError error, indicating that the class was compiled with Java 17 (class file version 61) but executed with Java 8 (class file version 52). Class file format major versions Java SE (JDK) The message accompanying the UnsupportedClassVersionError error provides this information in the form of class file versions, which can be mapped directly to a specific Java version, using the values from the table below. Recompile the code with an older Java/JDK compiler.Īs a variant of #2, recompiling the code can also be done by specifying the “target” or “release” parameter of a newer Java/JDK compiler to an earlier version of Java, to produce backward-compatible bytecode.īefore recompiling any code, it is important to know the runtime version of both the already compiled code and the environment in which it needs to run on.Run the code with a newer version of Java/JRE, or.

The solution to the UnsupportedClassVersionError error generally boils down to two options:

ECLIPSE JAVA 17 HOW TO

How to Fix the UnsupportedClassVersionError Error This almost invariably happens when someone attempts to run a program with a JDK or a JRE version that is incompatible with, i.e., lower than the Java version in which the code was compiled.

class file has been compiled with Java Development Kit (JDK) 15, trying to run it with Java Runtime Environment (JRE) 8 will trigger the UnsupportedClassVersionError error. The specific issue that the UnsupportedClassVersionError error raises is the detection of a class file which had been compiled with a newer version of Java than the one used to run it. UnsupportedClassVersionError class hierarchy As per Java’s error class hierarchy (Figure 1), an instance of UnsupportedClassVersionError is also a LinkageError which means that the error is identified during the JVM class linking process.įigure 1. The class extends which is thrown whenever the JVM attempts to read a class file and determines that the file is malformed or otherwise cannot be interpreted as a class file. What is the UnsupportedClassVersionError Error and Why Does it Happen? LinkageError instances in particular indicate critical class-related errors triggered during the class linking phase of the startup process, usually as a consequence of some post-compilation changes in the bytecode or the Java environment. This is because most of these errors occur as a result of abnormal conditions, often so severe that it is impossible to know or control what further execution of the program might do. An instance of the Error class (or any of its subclasses) is a throwable object that a program is not expected or advised to handle, but instead, should cause immediate termination of the program. This category of high level runtime errors in Java is represented by classes which are direct descendants of the class, including the class which denotes errors occurring during the aforementioned startup process. This allows for a certain category of errors to be captured and dealt with before the program effectively starts.

Namely, there is a process of dynamic loading, linking, and initializing of classes and interfaces by the Java Virtual Machine (JVM) that occurs at the very beginning of execution of any Java application. In Java, some of these runtime errors (namely throwable objects which are not exceptions) are triggered at a very early stage, while the program is basically starting up. Runtime errors are, therefore, harder to detect and prevent than compile-time errors. Runtime errors occur when a program is being executed and, in the case of compiled languages, after the program has been successfully compiled.

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