java.lang.UnsupportedClassVersionError : how to run code with a newer version of Java Runtime

Question

这个问题已经有答案了:

How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version (51 个回答)

how to check the jdk version used to compile a .class file [duplicate] (5 个回答)

已关闭 3 年前。

命令行编译时出现错误，如何获取所需版本的Java Runtime？

java.lang.UnsupportedClassVersionError: hello has been compiled by a more recent version of the Java Runtime (class file version 57.0), this version of the Java Runtime only recognizes class file versions up to 52.0

C:\Users\s\Documents\Documents>javac hello.java

C:\Users\s\Documents\Documents>java hello
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: hello has been compiled by a more recent version of the Java Runtime (class file version 57.0), this version of the Java Runtime only recognizes class file versions up to 52.0
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$100(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

Answer 1

看起来您使用的 JRE 与 Java 编译器不同。

java -version

和

javac -version 

您应该会看到版本有所不同。

一旦确认，您就可以修复导致差异的路径问题或使用 javac 设置编译目标

javac -target 1.8 hello.java

举个例子