How To Resolve Java.Lang.Unsupportedclassversionerror Amongst Example

java.lang.UnsupportedClassVersionError  is a quite mutual fault afterward NoClassDefFoundError or ClassNotFoundException they all seems to related to degree files but they all are dissimilar together with at that topographic point motility together with resolution are different. In this coffee tutorial nosotros volition reckon what is UnsupportedClassVersionError in Java? Why UnsupportedClassVersionError comes inwards Java? What is degree file format together with version numbers associated amongst it together with lastly how to resolve UnsupportedClassVersionError in Java. 

This article is inwards continuation of debugging tutorials similar How to remote debug Java programme inwards Eclipse together with 10 Java debugging tips inwards Eclipse. If y'all accept non read those article y'all may unwrap them useful.

 

How to resolve UnsupportedClassVersionError inwards Java

What is UnSupportedClassVersionError inwards Java?

Java.lang.UnsupportedClassVersionError is a subclass of java.lang.ClassFormatError. This is a variety of linking fault which occurs during linking stage accordingly java.lang.ClassFormatError has too derived from java.lang.LinkageError. As the advert suggests "UnSupportedClassVersionError" together with then it’s related to unsupported degree version, instantly questions comes what is degree version inwards Java? Well every source file is compiled into degree file together with each degree file has ii versions associated amongst it, major version together with tike version. 

The Version of degree file is represented every bit major_version.minor_version. This version is used to create upward one's hear format of degree file inwards Java.

According to Java Virtual Machine specification, “A JVM implementation tin back upward a degree file format of version v if together with exclusively if v lies inwards around contiguous gain Mi.0 v Mj.m. Only Dominicus tin specify what gain of versions a JVM implementation conforming to a sure as shooting liberate flat of the Java platform may support.” For example: JDK 1.2 supports degree file formats from version 45.0 to version 46.0 inclusive. So if a degree file has version 48.0 it agency that major version of degree file is "48" together with tike version is "0", which tells us that JDK 1.4 has been used to compile together with generate that degree file.

When UnSupportedClassVersionError inwards Java comes:

So instantly nosotros got the theory behind degree file format together with major together with tike version of degree file inwards Java. Now a 1 one k thousand dollar inquiry is when UnSupportedClassVersionError inwards Java does occur?  precise answer of this is "When JVM tries to charge a degree together with constitute that degree file version is non supported it throws UnSupportedClassVersionError together with it to a greater extent than oft than non occurs if a higher JDK version  is used to compile the source file and  a lower JDK version is used to run the program. for instance if y'all compile your coffee source file inwards JDK 1.5 together with y'all volition endeavour to run it on JDK 1.4 y'all volition larn fault "java.lang.UnsupportedClassVersionError: Bad version publish inwards .class file [at java.lang.ClassLoader.defineClass1(Native Method)]".

But its of import to depository fiscal establishment complaint is that vice-versa is non truthful "you tin compile your programme inwards J2SE 1.4 together with run on J2SE 1.5 together with y'all volition non larn whatever UnSupportedClassVersionError". When a higher JDK is used for compilation it creates degree file amongst higher version together with when a lower JDK is used to run the programme it constitute that higher version of degree file non supported at JVM flat together with results inwards java.lang.UnsupportedClassVersionError.

How to create UnSupportedClassVersionError

Now nosotros know the root motility of UnSupportedClassVersionError that nosotros are using a lower JVM for running the program. But major occupation is that stack delineate of UnSupportedClassVersionError volition non say y'all for which degree it’s coming. So if y'all are using multiple 3rd political party jars inwards your application y'all unwrap that it comes at a detail utilization when JVM tries to charge a degree from a detail jar. anyway nosotros all know that latest version of JDK is 1.6 together with then maximum version of degree file could live generated past times JDK 6, together with then past times using JDK vi nosotros tin solve UnSupportedClassVersionError, but many times its non tardily to only displace to higher JDK version. So I would suggest:

1) Find out due to which jolt or degree file this UnSupportedClassVersionError is coming?

2) Try to compile source code of that jolt amongst the JDK version y'all are using to run your program, if source is available.

3) If y'all don't accept source endeavour to unwrap the compatible version of that library.

4) Increase the JRE version y'all are using to run your program.

You tin become past times whatever approach to resolve UnSupportedClassVersionError based upon your need. Generally a higher JVM version is ok together with does non motility whatever occupation unless the degree file format is quite quondam together with no to a greater extent than supported past times Dominicus inwards higher JVMs. The best way to bargain amongst UnSupportedClassVersionError inwards Java is to utilization same version or JDK together with JRE for compiling together with running your program.

Example of UnSupportedClassVersionError inwards Java

You tin easily reproduce UnSupportedClassVersionError past times using javac of higher JDK together with "java" from lower Java version. Let’s reckon around of examples of UnSupportedClassVersionError inwards Java:

1) java.lang.UnsupportedClassVersionError: EquityTradingManager (Unsupported major.minor version 49.0)
      at java.lang.ClassLoader.defineClass0(Native Method)
      at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
==>Since nosotros know that major version 49 is supported past times JDK 1.5, together with then these volition "java.lang.UnsupportedClassVersionError” volition come upward if JVM used to run this programme is lower than Java 1.5.

2) Java.lang.UnsupportedClassVersionError: Bad version publish inwards .class file

3) java.lang.unsupportedclassversionerror unsupported classversion 50.0
==> Compile inwards JDK 1.6 together with running on lower version than Java 6.

4) java.lang.unsupportedclassversionerror unsupported classversion 49.0
==> compiled inwards Java v together with running on lower JVM than JDK 5.

5) java.lang.unsupportedclassversionerror bad version publish inwards eclipse.

==> Most of us utilization eclipse for edifice together with running projection around of us too utilization emmet for edifice project. In eclipse at that topographic point is around setting related to coffee source version which if y'all got wrong tin effect inwards "java.lang.unsupportedclassversionerror bad version number". together with then brand sure as shooting y'all accept right configuration. For instance if y'all compile amongst source compatible 1.6 y'all postulate JRE vi to execute the program. To depository fiscal establishment tally the compiler setting inwards eclipse become to project  ==>Properties==>Java Compiler every bit shown inwards image

Important indicate close UnSupportedClassVersionError inwards Java:

1) If y'all run across UnSupportedClassVersionError, depository fiscal establishment tally the JRE version y'all are using to run programme together with switch to higher version for quick solution.
2) java.lang.UnsupportedClassVersionError is derived from java.lang.LinkageError, together with then it volition non live detected inwards compile fourth dimension together with it volition exclusively come upward on runtime, exactly when JVM tries to charge a class.
3) Class file format which is identified using major version together with tike version. Class file format is assigned when y'all compile source file together with its depends on JDK version used to compile.
4) Its ever best practise to utilization same version of coffee for compilation together with execution to avoid whatever peril of UnSupportedClassVersionError.
5) UnSupportedClassVersionError is non related to java classpath , together with then don't confuse this amongst NoClassDefFoundError or ClassNotFoundException.

Major Class Versions of Various JDK

Following are the major version of class file format inwards criterion JDK environment.

JDK 1.1 = 45
JDK 1.2 = 46
JDK 1.3 = 47
JDK 1.4 = 48
JDK 1.5 = 49
JDK 1.6 = 50

You tin too larn version of "javac" (used for compilation) together with version of "java" (used for execution) every bit below
C:\equity trading\stocks>javac -version
javac 1.6.0-beta2

C:\equity trading\stocks>java -version
java version "1.6.0-beta2"
Java(TM) SE Runtime Environment (build 1.6.0-beta2-b86)
Java HotSpot(TM) Client VM (build 1.6.0-beta2-b86, mixed mode, sharing)

Now y'all tin position your JDK version based on degree file format version whenever y'all reckon java.lang.UnsupportedClassVersionError :)

Further Learning
Complete Java Masterclass
how coffee hashmap works, why String is immutable inwards java, why aspect together with notify needs to telephone telephone from synchronized context  interesting.

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