How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version

转自：https://stackoverflow.com/questions/10382929/how-to-fix-java-lang-unsupportedclassversionerror-unsupported-major-minor-versi

The version number shown describes the version of the JRE the class file is compatible with. The reported major numbers are: Java SE 9 = 53, Java SE 8 = 52, Java SE 7 = 51, Java SE 6.0 = 50, Java SE 5.0 = 49, JDK 1.4 = 48, JDK 1.3 = 47, JDK 1.2 = 46, JDK 1.1 = 45 (Source: Wikipedia) To fix the actual problem you should try to either run the Java code with a newer version of Java JRE or specify the target parameter to the Java compiler to instruct the compiler to create code compatible with earlier Java versions. For example, in order to generate class files compatible with Java 1.4, use the following command line: javac -target 1.4 HelloWorld.java With newer versions of the Java compiler you are likely to get a warning about the bootstrap class path not being set. More information about this error is available in blog post New javac warning for setting an older source without bootclasspath. shareimprove this answer edited Oct 11 '16 at 18:48 Victor Stafusa 6,11973959 answered Jul 11 '12 at 11:59 Juha Palomäki 19.6k12534

143   "The version number shown describe which version if Java was used to compile the code." No it does not.It shows the version of the JRE that the class file is compatible with. Using cross-compilation options you can use a 1.7 JDK to compile code with a class version of 1.1 (through 1.7). – Andrew Thompson Jan 10 '13 at 5:31  73   This answer does not explain how to fix it as the question asked? – Jonathan Leung Mar 5 '13 at 12:58 5   This is a nice solution for compiling to a previous version from Eclipse directly: stackoverflow.com/a/16345710/2091700 – Alphaaa May 23 '13 at 14:03 17   IN eclipse project=>Proerties=>java compiler; set "the compiler compliance level" to the version according to your jre or jdk. As for me, it's 1.6 for jre 1.6 – Sam Sep 25 '13 at 14:58  4   This may occur when compiler source is set in non-compliance with currently compiling JRE/JDK. For example i found the below values from eclipse .settings folder, org.eclipse.jdt.core.compiler.compliance=1.7, org.eclipse.jdt.core.compiler.source=1.7, org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.7. And my compiler was 1.6.0_32. The problem was resolved after changing the values to 1.6. The issue originated after i copied the project from a different workspace where i was using JDK 1.7 :( – Gana Dec 22 '14 at 6:22