Is Ant 1.9.4 compatible with Java 1.8?
The ant documentation is not very clear: it just says that it is compatible with a minimum version of Java 1.5.
How can I be sure that it is compatible with java 1.8?
Thank you!
This Ant Java Version Table indicates that ant 1.9.x needs a minimum version of 1.5. As Java takes great pains to maintain backwards compatibility, it would be extraordinary for an incompatibility to occur. Ant 1.10 requires Java 1.8.
We have been running 1.9.6 for many months with Java 8 without issue.
Taken from here
We recommend using 1.10.x unless you are required to use versions of Java prior to Java8 during the build process
To me this reads as not supported and might suddenly break.
Related
On the main page I noticed that JJWT is supposed to run on all JDK, which - since our project for all sorts of reasons is still stuck on v1.6 - sounded great.
With the last version maven retrieves however, the class version is not compatible.
And afterwards in the build wiki I noticed it specifies version 7.
Anyone have a clue what does run on v1.6.
Can I use an older version, or should I compile it myself maybe.
On the main page I noticed that JJWT is supposed to run on all JDK ...
That is definitely incorrect / inaccurate. The initial commits for the JJWT project were for JDK 1.6. And I can see that the code uses generics, so compiling / running for earlier than JDK 1.5 will be impossible.
The POM.xml file for the latest version of the project sets the source and target version for the project to JDK 1.7. So certainly the artifacts that a standard build will generate now will NOT run on a Java 6 platform. The class file version will be too recent for a Java 6 JVM to understand.
Now you could try changing the JDK level to 1.6 in the POM file in the HEAD version. However, the JDK version for JJWT was bumped past 1.6 four years ago, so there are liable to be build issues if you wind back. (The developers could have introduced Java 7+ dependencies; e.g. using try with resources syntax or Java 7+ APIs.)
A better idea would be to use an old version of JJWT. You should be able to figure out what version you need to use (or build) for JDK 1.6 compatibility by looking at the project's git history on Github. Look at the relevant changes to the POM file and when they happened. I think it is version 0.9.0 or thereabouts.
Of course a better solution would be "unstick" your project. JDK 1.6 is 8 years past its end of life, and 3 years past the end of Oracle's JDK 1.6 (paid) extended support.
My web application runs fine on JDK 1.7 but crashes on 1.8 with the following exception (during application server startup with Jetty 8). I am using Spring version: 3.2.5.RELEASE.
Exception:
org.springframework.core.NestedIOException: ASM ClassReader failed to parse class file - probably due to a new Java class file version that isn't supported yet
I assume that problem occurs because of spring and "asm.jar" library on which it depends.
How do I resolve this?
As #prunge and #Pablo Lozano stated, you need Spring 4 if you want compile code to Java 8 (--target 1.8), but you can still run apps on Java 8 compiled to Java 7 if you run on Spring 3.2.X.
Check out
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/new-in-4.0.html
Note that the Java 8 bytecode level (-target 1.8, as required by -source 1.8) is only fully supported as of Spring Framework 4.0. In particular, Spring 3.2 based applications need to be compiled with a maximum of Java 7 as the target, even if they happen to be deployed onto a Java 8 runtime. Please upgrade to Spring 4 for Java 8 based applications.
If you encounter this error even if you compile with -target 1.7, please note that this is because of a bug in Spring Framework which causes ASM classreader to load jdk classes (java.* or javax.*), which are, of course, compiled with -target 1.8.
This, combined with the old ASM version in spring 3.2.8 and below, which does not support parsing of 1.8 class files, can also lead to this error.
More info about the issue can be found here: https://jira.spring.io/browse/SPR-11719
This should be fixed in Spring Framework version 3.2.9, which is due to be released soon.
Of course, upgrading to Spring Framework 4 will also resolve the issue, as it already contains a newer version of ASM.
However, if for some reason you can't upgrade to version 4 yet, it's good to know there's an alternative (soon).
I had the same problem and solved it. I am using spring 3.x with java 8. If above solutions are not working change the jars and search whether those jars are compatible with the java version you are using or not. spring 3.x is not compatible with java 8.
I had the same problem,
1.Go to:
maven -> executive maven goal -> mvn clean
It helps :)
2.Invalid caches..
This problem might because of wrong selection of environments. I tried changing JRE to Java SE 1.8 which is the Java version installed.
Project>>Right click>>Properties>>Java Build Path>>Libraries>>Double click JRE system Library>>Execution Environment to JAVA VERSION INSTALLED.
if you use java 8 or next version you need to upgrade spring version and spring version should be 4.xxx
Spring 4 can be used for java 8 to resolve this issue. I just tested it and it works.
This issue is fixed since Spring 3.2.9-RELEASE version.
Fast-ClassPath-Scanner
https://github.com/lukehutch/fast-classpath-scanner using latest version.
On executing(get names of all classes in war which includes all jars and classes)
new FastClasspathScanner(basePackage).scan().getNamesOfAllClasses()
getting:
unsupportedclassversion error with jre 6
Please provide a solution to it or alternative to perform same.
FastClasspathScanner is compiled for java 1.7
When you try to load it in a 1.6 (JRE6) environment it fails with an UnsupportedClassVersionError. This error indicates that the class version (here 1.7) is not compatible with the JVM version (here 1.6).
Java 7 is not backwards compatible with Java 6. You could try to build the FastClasspathScanner library yourself unter 1.6 (not sure if that's possible). Or upgrade your project to Java 7.
Correct, I am the author of FastClasspathScanner, and it's not a goal to get this working with JRE6. However, patches for supporting 1.6 are welcome.
My web application runs fine on JDK 1.7 but crashes on 1.8 with the following exception (during application server startup with Jetty 8). I am using Spring version: 3.2.5.RELEASE.
Exception:
org.springframework.core.NestedIOException: ASM ClassReader failed to parse class file - probably due to a new Java class file version that isn't supported yet
I assume that problem occurs because of spring and "asm.jar" library on which it depends.
How do I resolve this?
As #prunge and #Pablo Lozano stated, you need Spring 4 if you want compile code to Java 8 (--target 1.8), but you can still run apps on Java 8 compiled to Java 7 if you run on Spring 3.2.X.
Check out
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/new-in-4.0.html
Note that the Java 8 bytecode level (-target 1.8, as required by -source 1.8) is only fully supported as of Spring Framework 4.0. In particular, Spring 3.2 based applications need to be compiled with a maximum of Java 7 as the target, even if they happen to be deployed onto a Java 8 runtime. Please upgrade to Spring 4 for Java 8 based applications.
If you encounter this error even if you compile with -target 1.7, please note that this is because of a bug in Spring Framework which causes ASM classreader to load jdk classes (java.* or javax.*), which are, of course, compiled with -target 1.8.
This, combined with the old ASM version in spring 3.2.8 and below, which does not support parsing of 1.8 class files, can also lead to this error.
More info about the issue can be found here: https://jira.spring.io/browse/SPR-11719
This should be fixed in Spring Framework version 3.2.9, which is due to be released soon.
Of course, upgrading to Spring Framework 4 will also resolve the issue, as it already contains a newer version of ASM.
However, if for some reason you can't upgrade to version 4 yet, it's good to know there's an alternative (soon).
I had the same problem and solved it. I am using spring 3.x with java 8. If above solutions are not working change the jars and search whether those jars are compatible with the java version you are using or not. spring 3.x is not compatible with java 8.
I had the same problem,
1.Go to:
maven -> executive maven goal -> mvn clean
It helps :)
2.Invalid caches..
This problem might because of wrong selection of environments. I tried changing JRE to Java SE 1.8 which is the Java version installed.
Project>>Right click>>Properties>>Java Build Path>>Libraries>>Double click JRE system Library>>Execution Environment to JAVA VERSION INSTALLED.
if you use java 8 or next version you need to upgrade spring version and spring version should be 4.xxx
Spring 4 can be used for java 8 to resolve this issue. I just tested it and it works.
This issue is fixed since Spring 3.2.9-RELEASE version.
I am looking for clarification in jdk versions.
I am getting error
java.lang.UnsupportedClassVersionError:Bad version number in .class file"
I hope this error is for different jdk version. I am having myeclipse6.0.1 and weblogic10.3.
Now, in my systems has jdk1.5 but weblogic has jdk1.6, as well myeclipse supporting 1.5 only.
I read the all forums and they said compile is different version and running different version.
So, here i thought program compliling 1.5 and running 1.6.
Is it correct ?
This means that the Java program was compiled for a newer version of Java than you are trying to run it with.
The easiest way to be certain is to use the same version of Java for compiling and building as is to be used on the final system. For you, this is most likely Java 5.