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Docker starts the springboot project and reports java version error

I use the following dockerfile to generate a image call userservice
FROM java:8-alpine
COPY ./userservice.jar /tmp/userservice.jar
ENTRYPOINT java -jar /tmp/userservice.jar
then I use the following command to run container
docker run --name userservice_container userservice
But the terminal prompts that the java version does not match，as follows:
Exception in thread "main" java.lang.UnsupportedClassVersionError: com/imortal/UserApplication has been compiled by a more recent version of the Java Runtime (class file version 55.0), 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(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:151)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:46)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:107)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88)
So I went to check the compiled bytecode version, it is indeed 52, I don’t know why this error is still reported
javap -verbose .\UserApplication.class
public class com.imortal.UserApplication
minor version: 0
major version: 52
flags: (0x0021) ACC_PUBLIC, ACC_SUPER
this_class: #2 //
com/imortal/UserApplication
super_class: #4 // java/lang/Object
interfaces: 0, fields: 0, methods: 2, attributes: 2

Use a docker image that has a compatible jdk version, so that it doesn't create any conflict with all the microservices that you are having. This issue probably is occuring because one of your microservices is build on some other jdk version.

Can't run JAR files because of outdated JRE but updating it does nothing

I tried to open the jar with "java -jar blah.jar".
this is the outcome:
java -jar Desktop/lambertone2.jar
Exception in thread "main" java.lang.UnsupportedClassVersionError: main/Main has been compiled by a more recent version of the Java Runtime (class file version 54.0), 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(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:56) .
I went to Oracle site to download the latest JRE but it doesn't change anything.
All this happened some day ago where the update section of java told me to erase java because it was obsolete, so i removed it and reinstalled it.
if i use the command java --version it says me that the command is unsupported.
if i use javac --version it says that it is version 10.

How do I run an HBase instance on Windows 7?

I followed the following instructions:
Download Hbase from https://hbase.apache.org/
Picked the suggested mirror and the most stable release.
I picked the bin tar tgz file
I extracted it on my Windows box
Found this: http://hbase.apache.org/0.94/book/quickstart.html
I have cygwin already I set the
config at hbase-site.xml to:
<configuration>
<property>
<name>hbase.rootdir</name>
<value>http://file:///ht_data/hbase/hbase</value>
</property>
<property>
<name>hbase.zookeeper.property.dataDir</name>
<value>/ht_data/hbase/zookeeper</value>
</property>
</configuration>
Go to http://java.sun.com/javase/downloads/index.jsp
Install the one for windows x64
I added a new environment variable with
Name : JAVA_HOME
Value: C:\Program Files\Java\jdk1.8.0_141
From Windows cmd:
cd "\hbase-1.2.6"
bin\start-hbase.cmd
But I get:
`cygpath: can't convert empty path java.lang.UnsupportedClassVersionError: org/apache/hadoop/hbase/regionserver/HRegionServer : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at http://java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at http://java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at http://java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at http://java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
Could not find the main class:
org.apache.hadoop.hbase.regionserver.HRegionServer. Program will exit.
Exception in thread "main" `
and
`cygpath: can't convert empty path java.lang.UnsupportedClassVersionError: org/apache/hadoop/hbase/master/HMaster : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at http://java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at http://java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at http://java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at http://java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
Could not find the main class: org.apache.hadoop.hbase.master.HMaster.
Program will exit.
Exception in thread "main" `
Do I need to install Hadoop to get this going at all? I just want to get a hello world going for now
I uncommented and modified the following on my hbase-env.sh FYI:
`export JAVA_HOME="C:\Program Files\Java\jdk1.8.0_141"
export HBASE_CLASSPATH="<my path>\hbase-1.2.6\lib\zookeeper-3.4.6.jar"
export HBASE_OPTS="-XX:+UseConcMarkSweepGC"`

maven version exception on mac

When I execute "mvn --version" I get this error:
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/maven/cli/MavenCli : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637)
at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:401)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:254)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
at org.codehaus.plexus.classworlds.launcher.Launcher.getMainClass(Launcher.java:144)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:266)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Maven version I installed is maven 3.3.3
My java version is:
java version "1.8.0_65"
Java(TM) SE Runtime Environment (build 1.8.0_65-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.65-b01, mixed mode)
echo $PATH returns:
/Library/Maven/bin:/Library/Frameworks/Python.framework/Versions/3.5/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin
How to solve the problem of Maven?

$JAVA_HOME should be pointing to 1.8.0_65 as in your case.
If you want it to permanently change the value of JAVA_HOME, you will have to add the command to your ~/.profile file. Below are instructions on how to accomplish this instead:
Open up Terminal.app (Applications → Utilities → Terminal)
Type:
emacs .profile
Add this to the end of the .profile file:
JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home
export JAVA_HOME;
Note that JAVA_HOME should be the path of your JDK directory.
Save and exit emacs (ctrl-x, ctrl-s; ctrl-x, ctrl-c)
Open a new Terminal window (cmd-n) and type:
$JAVA_HOME/bin/java -version

Play Framework configuration with java major.minor version

I want to check out the play framework. Therefore i have downloaded it (https://example.lightbend.com/v1/download/play-java - Version 2.5.x Java Seed) and ran sbt command in command prompt. I get this error, although Java 8 seems to be configured correctly. How do i fix this major.minor version problem. Here is my console output:
d:\code\play base\downlaoded\play-java>set $JAVA_HOME
$JAVA_HOME=c:\Java\java8sdk\
d:\code\play base\downlaoded\play-java>java -version
java version "1.8.0_102"
Java(TM) SE Runtime Environment (build 1.8.0_102-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.102-b14, mixed mode)
d:\code\play base\downlaoded\play-java>sbt
d:\code\play base\downlaoded\play-java>.\sbt-dist\bin\sbt.bat
[info] Loading project definition from D:\code\play base\downlaoded\play-java\project
[info] Set current project to play-java-intro (in build file:/D:/code/play%20base/downlaoded/play-java/)
java.lang.UnsupportedClassVersionError: com/typesafe/config/ConfigException : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at com.typesafe.sbt.web.SbtWeb$$anonfun$com$typesafe$sbt$web$SbtWeb$$load$1.apply(SbtWeb.scala:559)
at com.typesafe.sbt.web.SbtWeb$$anonfun$com$typesafe$sbt$web$SbtWeb$$load$1.apply(SbtWeb.scala:559)
at scala.Option.fold(Option.scala:157)
at com.typesafe.sbt.web.SbtWeb$.com$typesafe$sbt$web$SbtWeb$$load(SbtWeb.scala:573)
at com.typesafe.sbt.web.SbtWeb$$anonfun$globalSettings$1$$anonfun$apply$1.apply(SbtWeb.scala:143)
at com.typesafe.sbt.web.SbtWeb$$anonfun$globalSettings$1$$anonfun$apply$1.apply(SbtWeb.scala:143)
at scala.Function1$$anonfun$andThen$1.apply(Function1.scala:55)
at sbt.Project$.setProject(Project.scala:341)
at sbt.BuiltinCommands$.doLoadProject(Main.scala:507)
at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:488)
at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:488)
at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:59)
at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:59)
at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:61)
at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:61)
at sbt.Command$.process(Command.scala:93)
at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:96)
at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:96)
at sbt.State$$anon$1.process(State.scala:184)
at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:96)
at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:96)
at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
at sbt.MainLoop$.next(MainLoop.scala:96)
at sbt.MainLoop$.run(MainLoop.scala:89)
at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:68)
at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:63)
at sbt.Using.apply(Using.scala:24)
at sbt.MainLoop$.runWithNewLog(MainLoop.scala:63)
at sbt.MainLoop$.runAndClearLast(MainLoop.scala:46)
at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:30)
at sbt.MainLoop$.runLogged(MainLoop.scala:22)
at sbt.StandardMain$.runManaged(Main.scala:57)
at sbt.xMain.run(Main.scala:29)
at xsbt.boot.Launch$$anonfun$run$1.apply(Launch.scala:109)
at xsbt.boot.Launch$.withContextLoader(Launch.scala:128)
at xsbt.boot.Launch$.run(Launch.scala:109)
at xsbt.boot.Launch$$anonfun$apply$1.apply(Launch.scala:35)
at xsbt.boot.Launch$.launch(Launch.scala:117)
at xsbt.boot.Launch$.apply(Launch.scala:18)
at xsbt.boot.Boot$.runImpl(Boot.scala:41)
at xsbt.boot.Boot$.main(Boot.scala:17)
at xsbt.boot.Boot.main(Boot.scala)
[error] java.lang.UnsupportedClassVersionError: com/typesafe/config/ConfigException : Unsupported major.minor version 52.0
[error] Use 'last' for the full log.
Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore? q
d:\code\play base\downlaoded\play-java>