How to fix java lang UnsupportedClassVersionError Unsupported major minor version

Question

I am trying to use Notepad   as my all-in-one tool edit  run  compile  etc   I have JRE installed  and I have setup my path variable to the     bin directory   When I run my  Hello world  in Notepad    I get this message   java lang UnsupportedClassVersionError  test hello world    Unsupported major minor version 51 0     at java lang ClassLoader defineClass1 Native Method      at java lang ClassLoader defineClassCond Unknown Source                                                     I think the problem here is about versions  some versions of Java may be old or too new    How do I fix it  Should I install the JDK  and setup my path variable to the JDK instead of JRE  What is the difference between the PATH variable in JRE or JDK

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You have compiled your Java class with JDK 7 and you are trying to run same class on JDK 6

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Many answers refer to IDE s like Eclipse  However  the question relates to native development with Notepad     The core reason of the named error is a mismatch of the used Java Runtime Environment and used classes respectively libraries  The goal of the following descriptions is to compile without any additional installation   1   Check the definition in the PATH variable  If there is defined   C  Program Files  x86  Common Files Oracle Java javapath  and or  C  ProgramData Oracle Java javapath  These paths link to java javac with a fixed java version  You can check this versions in this folder with javac -version  Result can be   java version  1 8 0 231   This means  Java version 8 is in use  Replace this entries with  JAVA HOME  bin  If the JDK s was installed manually  check whether JAVA HOME is set in the environment  If not  add it  here e g  with   JAVA HOME  C  Program Files Java jdk1 7 0 80   2   I have build the project on command-line with gradle  In build gradle was defined   android       buildToolsVersion  24 0 1      dependencies           compile  com android support design 23 0 1          compile  com android support support-v4 23 0 1                                The used build-tools dx-files are newer then other components  Therefore a modification is required   buildToolsVersion  23 0 1

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I got the same issue with Spring Source Tool  STS  IDE for a Grails project  I checked the installed Java version and the project Java version were 1 7    Later I found that in GGTS ini file the Java version was set to 1 6   Solution   -Dosgi requiredJavaVersion 1 6 changed to -Dosgi requiredJavaVersion 1 7 Add below two lines before -vmargs -vm jdk1 7 0 21 jre lib amd64 server libjvm so  Problem solved  Happy coding

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First let s get some basics right     JRE is a component in NetBeans Eclipse standalone that is going to provide you with libraries  JVM  Java plugins  amp  Java web start  Note that it does not provide compliers or debuggers   JDK is the superset of JRE along with compliers and debuggers   So when you have your default library as a JRE instead of JDK  you are going to have a nice time importing stuff  but it won t compile   Instead  set your path to JDK  I use NetBeans  and I set them using netbeans conf in netbeans etc netbeans conf and change the path

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Your Java file is compiled with a different version  higher compiler version  than the version  lower runtime version  you are trying to run it with   It is basic understanding that classes compiled with lower versions are expected to run in the later higher versions  But the opposite  compiled with higher compiler version and trying to run it with lower runtime version  is quite not possible sometimes   Hence you are shown this error  when trying to execute your program  Unsupported major minor version x x     Q  I have created an application in Java 7  but when my users try to   run it they get an Unsupported major minor version 51 0 error  What   does this mean and what can I do about it       A  If you compile an application using javac in Java 7  the resulting classfiles will have the 51 0 version number  Versions of   Java prior to 7 do not recognize this number  so your users will have   to upgrade to Java 7 prior to running your application  If you are not   using any Java 7 APIs you can try to compile your application using   javac -target 1 6 to create a 1 6-compatible classfile  If your   application is deployed using webstart you can specify the minimum   version required  For more information  see the docs on Java Web Start   and JNLP here  This issue will go away once we trigger autoupdate to   Java 7 for end-users currently having Java 6 on their desktops  The   timeline for this is not yet determined  we want to give developers   time to work out any issues between their code and JDK 7 first     Source  oracle com

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The answer is for the problem   Exception in thread  main  java lang UnsupportedClassVersionError  edu stevens cs549 dhts main LocalContext   Unsupported major minor version 52 0  I was having the same problem  For those who were having this trouble in AWS ec2 instances  and have somehow got redirected here to this question  I am answering for those  and would like to share that how I did it  I was having the trouble because Amazon EC2 instances were running java version 1 7 and maybe my project was not compatible with it because I was using Maven and it kind of preconfigured for java 1 8  So I installed new version of java   sudo yum -y install java-1 8 0  And then the important step is to remove the older version   sudo yum remove java-1 7 0-openjdk   Remember to delete it after installing the new version  else it would continuously be using the same older version and I hope it resolves your problem  which did in my case

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In Eclipse s menu Window -  Preferences -  Java -  Compiler check also  Configure Project Specific Settings    If you stil have the error with same Java version  try to delete build folder of your project manually  Then restart Eclipse

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For me  I was getting this error on the com sun javadoc Doclet class   After some digging  I found that I accidentally copied the tools jar from Java 8 into my Java 7 folder   Finding the tools jar for Java 7 and putting it back into the folder fixed my issue   So something to try

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As answered elsewhere by several people  the Java program is being run on an older version of Java than the one it was compiled it for  It needs to be  crosscompiled  for backward compatibility  To put it another way  there is a mismatch between source and target Java versions   Changing options in Eclipse menus don t answer the original poster  who said he she is not using Eclipse  On OpenJDK javac version 1 7  you can crosscompile for 1 6 if you use parameters -source and -target  plus provide the rt jar -file of the target version  that is  the older one  at compile time  If you actually install the 1 6 JRE  you can point to its installation  for example   usr lib jvm java-6-openjdk-i386 jre lib rt jar on Ubuntu   usr jdk jdk1 6 0 60 jre lib rt jar on SunOS apparently  Sorry  I don t know where it is on a Windows system   Like so   javac -source 1 6 -target 1 6 -bootclasspath  usr lib jvm java-6-openjdk-i386 jre lib rt jar HelloWorld java   It looks like you can just download rt jar from the Internet  and point to it  This is not too elegant though   javac -source 1 6 -target 1 6 -bootclasspath   rt jar HelloWorld java

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I have faced the same problem  and I fixed it in Linux   Check your  JAVA HOME  Need JDK 1 8 to compile build APK  Install Java JDK 1 8 and change the JAVA HOME  Edit    bashrc and add your JDK 1 8 path as JAVA HOME   export JAVA HOME  usr lib jvm java-8-oracle jre   And source    bashrc  Close the current terminal window tab and run  JAVA HOME to check the path

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I had the same situation but any of above tips didn t help    In our environment we had tomcat running as a service on Windows  We installed Java 1 7 and set up JAVA HOME on this version  Off course the sources were built on Java 1 7  Nevertheless the tomcat said that it use previous version of JVM  After a deep analized turn out that the Tomcat service installed on Windows still keeping the old value for JAVA HOME pointing to Java 1 6  After installing new Tomcat service everything were resolved  So the conclusion is  When you change java version and tomcat running as a service  you have to reinstall tomcat service

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If you use Maven  set your Java compile level  Open a command line and write java -version for your compile level    If you use IntelliJ IDEA  select project   File   Settings   Build Execution Deployment   Compiler   Java Compiler  Then change byte code as 1 7 like this image

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I tried everything  Reinstalling Tomcat is what finally worked  Here s what I ve checked before reinstalling   Make sure your environmental variables look like this      echo  JAVA HOME C  Program Files Java jdk1 7 0 51    echo  JRE HOME C  Program Files Java jdk1 7 0 51 jre bin   Make sure Eclipse is using the same jre you set JAVA HOME to  if JAVA HOME is not set it will look at JRE HOME   Window  gt  Prefrences  gt  Java  gt  Installed JREs  the checked one is the default one   If you made any changes to any of your tomcat files especially catalina bat or startup bat  then you may be telling tomcat to look at a different version of java than the one you set to JAVA HOME C  Program Files  x86  Apache apache-tomcat-7 0 26 bin

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In Eclipse  I just went to menu command Window -  Preferences -  Java -  Compiler and then set  Compiler compliance level  to 1 6

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I m using OS X v10 11 5  El Capitan   and I tried setting JAVA HOME and forcing the  correct  Java version via Maven  Nothing helped   The problem happened when the OS X account was logged out while the application was still running  After logging in again  OS nbsp X opened the old terminal session with greyed-out history  I used the same terminal session to build the project  but failed with the unsupported class version error   Cleaning the Maven project didn t help at all   To solve the problem  I simply had to close the auto-opened terminal window and use a new one

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Based on this     J2SE 8   52 J2SE 7   51 J2SE 6 0   50 J2SE 5 0   49 JDK 1 4   48 JDK 1 3   47 JDK 1 2   46 JDK 1 1   45   In Eclipse  right click on project in package explorer   Build Path -  Configure Build Path  Under   Java Build Path -  Libraries -  Add Library -  JRE System Library -  Installed JREs -  Search   Add the required JRE by selecting the library in the list available after the search is complete

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I had a similar situation on Mac  and the following process worked for me   In the terminal  type  vi    profile   Then add this line in the file  and save  export JAVA HOME  Library Java JavaVirtualMachines jdk lt version gt  jdk Contents Home   where version is the one on your computer  such as 1 7 0 25   Exit the editor  then type the following command make it become effective  source    profile    Then type java -version to check the result  java -version    What is  profile file       profile file is a hidden file  It is an optional file which tells the system which commands to run when the user whose profile file it is logs in  For example  if my username is bruno and there is a  profile file in  Users bruno   all of its contents will be executed during the log-in procedure    Source  http   computers tutsplus com tutorials speed-up-your-terminal-workflow-with-command-aliases-and-profile--mac-30515

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Add this to your pom xml file    lt project      gt       lt properties gt           lt maven compiler source gt 1 7 lt  maven compiler source gt           lt maven compiler target gt 1 7 lt  maven compiler target gt       lt  properties gt   lt  project gt    Where 1 7 is the Java version you intend to use  This overwrites the Maven compiler setting  so it s good to debug from here

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you can specify the  target  for the compiler in the build xml file  if you are using ant  just like below     lt target name  compile  depends  init  gt       lt javac executable    JAVA HOME  bin javac  srcdir    src dir   target  1 6  destdir    classes dir   debug  true          deprecation  true  classpathref  compile classpath  encoding  utf8  gt           lt include name       java    gt       lt  javac gt   lt  target gt

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You are trying to run your program with a Java version that does not support the version in which the code was compiled  So basically you must have compiled your code with a higher version and trying to run it using a lower version   As you are getting  Unsupported major minor version 51 0   and version 51 0 corresponds to J2SE 7 you have most probably compiled your code in Java 7 and trying to run it using a lower version  Check what java -version displays  It should be the Java 7 version  If not make appropriate changes in the PATH JAVA HOME  Or you can compile with the same version you are trying to run the code  If the configurations are confusing you can always give absolute path  home user jdk1 7 0 11 bin javac and  home user jdk1 7 0 11 bin java

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You can have some JAR library compiled in Java 7  and you have only Java 6 as Java Runtime  It  could happen with some new libraries

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I had the same error message when running Ant from Eclipse  but the other solutions mentioned here didn t solve my problem  The funny thing was that running Ant from the Windows command line was running fine  so it had to be a configuration issue within Eclipse   It turned out that under Eclipse you can specify the environment that Ant should be running with and this was set as a JRE instead of a JDK    Go to  Run -  External Tools -  External Tools Configurations     Select the Ant build xml for your project  if you have multiple projects  Activate the Tab  JRE  Here was selected  Separate JRE  jre6   When I changed this to a JDK from the 1 6 or 1 7 series  the error was gone

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Try changing you java from java6 to java8 It might help

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You have used a higher version of the JDK to compile and trying to run from a lower version of JDK JRE   To check this  see the version information   javac -version  java -version   They will be different and javac will have a higher version number   To get around this  run using java from the JDK version or if you have a newer JRE JDK that will work as well   which javac will tell you the location  for example   usr bin javac  Just run directly using  usr bin java  lt program gt    OR you can set the environment variable as a permanent solution

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If you re facing this issue while using Maven  you can compile your code using the plug-in Maven Compiler     lt build gt           lt plugins gt               lt plugin gt                   lt groupId gt org apache maven plugins lt  groupId gt                   lt artifactId gt maven-compiler-plugin lt  artifactId gt                   lt version gt 3 1 lt  version gt                   lt configuration gt                       lt source gt 1 6 lt  source gt                       lt target gt 1 6 lt  target gt                   lt  configuration gt               lt  plugin gt                 UPDATE  set source and target to 1 8  if you are using JDK 8

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If you have a second project added to your build path make sure it has the same compiler version as your first one  Properties -  Java Compiler -  Compiler compliance level

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If someone is using Gradle  then put this in build gradle  java       sourceCompatibility   JavaVersion VERSION 1 7     targetCompatibility   JavaVersion VERSION 1 7     We are telling the compiler to enable the byte code to be compatable with version java 7 java version in which i want to run the class  in the above case

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Since java 9 -target is replaced by --release   Till java 11  the available numbers for --release are 6 7  8  9  10  11  And you can guess the future versions will be 12  13  and go on   To compile for an older target jvm  using javac --release 7 Tmp java    this will generate  class file that could run on jvm    7   Then you can check the target version via   javap -v Tmp   grep version  in the output  major version identify the target jvm version    55 -  java 11 54 -  java 10 53 -  java 9 52 -  java 8 51 -  java 7 50 -  java 6   Future version will remove more older versions    As of java 11  major versions  lt   49  java version  lt   5   are not supported  As of java 12 and 13  major versions  lt   50  java version  lt  6   are not supported    You can find out which target versions are support by current javac  via command    javac -help   grep releases

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I solved it  I ran   JAVA HOME  usr lib jvm java-7-openjdk-i386   The error is misleading  Unsupported major minor version 51 0  This gives the impression that version 51  Java 7  is not supported  And we should use Java 6   The error should have been      The current Java version  50  is unsupported  Use Java version 7  51 0 and greater  instead

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In my case the problem occured because of different versions of Java in  JAVA HOME and  PATH   echo  JAVA HOME  usr lib jvm java-7-openjdk-amd64 jre echo  PATH  opt jdk jdk1 8 0 151 bin  usr lib jvm java-7-openjdk-amd64 jre bin  usr local bin  usr bin  bin   Once I updated them to be the same version of Java the problem was gone   export JAVA HOME  opt jdk jdk1 8 0 151 export PATH  JAVA HOME bin  PATH

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Oh Mac OS X I was able to solve this problem by setting the JAVA HOME variable   export JAVA HOME  Library Java JavaVirtualMachines jdk1 7 0 75 jdk Contents Home

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I have faced the same problem when I was working with an Ant script to build my application   I use Eclipse for my application development  and I changed the compiler version in build properties of the project  But that didn t work for me  Then I found out that I can provide the compiler version in the Ant script   I modified the Ant script at the section where it compile Java files    lt target name  build-java  depends  prepare-build  gt       lt echo message  Compiling java files   gt       lt javac                 target  1 5          lt  javac gt   lt  target gt    This worked for me to resolve the unsupported major minor issue

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As you know it is always good practice to have enviornment variable Java home for jdk Java development Kit  bin directory    looking at your issue above this seems that JRE- runtime environment is looking for a class which is not compatible in Superset library of JDk  I would recommend have a completed package of JDK and JRE or Jboss if required  from Oracle download source directly to avoid any such issues

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I had the problem whereby I was having to run a Maven compilation on my project from the command line in order to run my unit tests  if I made a change to the test class and let Eclipse automatically recompile it  then I got the  Unsupported major minor version 51 0  error   I do have both JDK6 and JDK7 installed  but all my JRE settings were pointing at 1 6  both in the pom and from the project properties page in Eclipse  No amount of Maven Update Project and or refreshing solved this   Finally I tried closing the project and re-opening it  and this seemed to fix it  HTH

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I got the same problem  and I fixed this issue by this solution on a Mac  I hope it helps someone   It s because the system doesn t know about the newer version of JDK  and it still points to the old JDK

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I solved this issue for me by checking that Maven Dependencies were being deployed in Deployment Assembly  In my case they were not    Adding it fixed the problem

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Don t worry  I got it solved   It is actually simple - you need to install BOTH JRE   JDK with the same version   JRE 6 -  JDK 6  JRE 7 -  JDK 7  And so on

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make sure you check Environment variables versions of java   it could be just the difference between the versions of JAVA HOME  JDK path  and JRE HOME  JRE path    that cause the problem

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I got the same problem with a project written in 1 7 and tried to execute in 1 6   My solution in Eclipse    Right click on your Project Properties -  Java Build Path -  Libraries Select your JRE System Library and click Edit on the right  and choose the target JRE  Now go to Java Compiler on the left  and change the Compiler compliance level to your target     That worked for me

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How do I fix it    This error means that the JRE that is being used to execute your class code does not recognise the version of Java used  Usually because the version of Java that generated your class file  i e  compiled it  is newer   To fix it  you can either   a  Compile your Java sources with the same  or older  version of the Java compiler as will be used to run it  i e  install the appropriate JDK   b  Compile your Java sources with the newer version of the Java compiler but in compatibility mode  i e  use the -target parameter   c  Run your compiled classes in a JRE that is the same  or newer  version as the JDK used to compile the classes   You can check the versions you are currently using with javac -version for the compiler  and java -version for the runtime      Should I install the JDK  and setup my PATH variable to the JDK   instead of JRE    For compilation  certainly  install and configure the specific JDK that you want   For runtime  you can use the one that comes with the JDK or a standalone JRE  but regardless  make sure that you have installed the right versions and that you have configured your PATH such that there are no surprises      What is the difference between the PATH variable in JRE or JDK    The PATH environment variable tells the command shell where to look for the command you type  When you type java  the command shell interpreter will look through all the locations specified in the PATH variable  from left to right  to find the appropriate java runtime executable to run  If you have multiple versions of Java installed - i e  you have the java executable in multiple locations specified in the PATH variable  then the first one encountered when going from left to right will be the one that is executed   The compiler command is javac and only comes with the JDK  The runtime command is java and comes with the JDK and is in the JRE   It is likely that you have one version  51 0   Java 7  of javac installed  and you also have the same version of java installed  but that another previous version of java is appearing earlier in the PATH and so is being invoked instead of the one you expect

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In my case the problem was in the server runtime configuration     Check the JRE is the version you need     The project was in version 1 7 and the server JRE was set as 1 6  after changing to the proper java version it s launched fine

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java lang UnsupportedClassVersionError happens because of a higher JDK during compile time and lower JDK during runtime

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Today  this error message appeared in our Tomcat 7 on Ubuntu 12 04 2 LTS  Precise Pangolin        var log tomcat7 localhost 2014-04-08 log     Apr 8  2014 9 00 55 AM org apache catalina core StandardContext filterStart    SEVERE  Exception starting filter struts2    java lang UnsupportedClassVersionError  controller ReqAccept   Unsupported major minor version 51 0  unable to load class controller ReqAccept    The Struts application is compiled with Java 7   It turned out  someone uses  service tomcat  stop start   to restart Tomcat 7        ps -ef   grep java   tomcat7  31783 1 32 20 13   00 00 03  usr lib jvm default-java bin java         usr lib jvm default-java bin java -version   java version  1 6 0 27    Which causes the  Unsupported major minor version 51 0  error   When we used   etc init d tomcat7  stop start   to restart Tomcat 7  the problem was solved        ps -ef   grep java   tomcat7  31886 1 80 20 24   00 00 10  usr local java jdk1 7 0 15 bin java      usr local java jdk1 7 0 15 bin java -version   java version  1 7 0 15

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Had this problem when I reverted to Java 6 and tried to run classes previously compiled with Java 7  What worked for me was Preferences   java   compiler --  set compliance level to 1 6 and crucially  configure project settings

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Install JDK 7 0 55 and set the Java for Eclipse for JDK 7 0 55  Build the project with JDK 7 0 55 by configuring on build path JDK 7 0 55  Set the compiler in Eclipse for JDK 7 0 55 by menu Windows -  Preferences -  Java -  Compiler - choose 1 7

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The most common issue is misconfiguration of your JAVA HOME variable which should point to the right Java Development Kit library  if you ve multiple installed   To find where SDK Java folder is located  run the following commands   jrunscript -e  java lang System out println java lang System getProperty  java home        Debian Ubuntu  To check which java  openjdk  you ve installed  check via   dpkg -l  openjdk     grep  i   or   update-java-alternatives -l   To change it  use   update-alternatives --config java   Prefix with sudo if required   to select the alternative java version   Or check which are available for install   apt-cache search  openjdk   Prefix with sudo if required   Then you can install  for example   apt-get install openjdk-7-jre   Prefix with sudo if required   Fedora  Oracle Linux  Red Hat  Install upgrade appropriate package via   yum install java-1 7 0-openjdk java-1 7 0-openjdk-devel      The java-1 7 0-openjdk package contains just the Java Runtime Environment  If you want to develop Java programs then install the java-1 7 0-openjdk-devel package    BSD  There is an OpenJDK 7 package in the FreeBSD Ports collection called openjdk7 which probably needs to be reconfigured   See  OpenJDK wiki page   Windows  Just install appropriate  Java SE Development Kit library from the Oracle site or install   Jenkins  If you re experiencing this issue with Jenkins  see    JENKINS-30561 - Unable to launch agent using SSH   However selecting the right version of Java  newer  with update-alternatives should work

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The version number shown describes the version of the JRE the class file is compatible with  The reported major numbers are  Java SE 15   59  Java SE 14   58  Java SE 13   57  Java SE 12   56  Java SE 11   55  Java SE 10   54  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 a blog post New javac warning for setting an older source without bootclasspath

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This error means you re trying to load a Java  class  file that was compiled with a newer version of Java than you have installed   For example  your  class file could have been compiled for JDK 7  and you re trying to run it with JDK 6   So the solution is to either    Upgrade your Java runtime or Recompile the class if you have the source  using your local Java compiler  if you have one     javac FileName java   For developers  this can happen if another developer checks in a  class file  and they ve got a newer version of java than you have

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Yet another way to fix this on Mac OS X with Homebrew installed  is this   brew install Caskroom cask java

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When I installed JDK 1 7  the problem got solved

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I had the same problem after switching to JDK 6 to compile a dependency module  then switched but to JDK 8  Rerun the probject and compiler complained about unsupported major minor version  I verified the Java version it was 1 8 for both the JVM and Maven  After many tries and googling the problem was not solved  so i though what if i restart the computer  Windows 8    I did restart  rerun the project again and problem was solved

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Click Properties in a project  Go to Java Build Path  Click Add Library  Click Next on JRE System Library  Select the one you need if not selected by default  Click Finish    You re done

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

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