Bad class file magic or version

Question

I already know that question has been already asked very often and answers, but no one of the answers i found fixed my problem.

It's the error:

Error:Gradle: Execution failed for task ':ffcommunity:preDexDebug'.
 com.android.ide.common.internal.LoggedErrorException: Failed to run command:
    D:\Android SDK\sdk\build-tools\20.0.0\dx.bat --dex --output D:\Users\ReVo\Documents\IntelliJ IDEA\FFCommunity\ffcommunity\build\intermediates\pre-dexed\debug\bananaquery-2ee85432877a057e7414910b8127805535139d5d.jar D:\Users\ReVo\Documents\IntelliJ IDEA\FFCommunity\ffcommunity\libs\bananaquery.jar
Error Code:
    1
Output:
    UNEXPECTED TOP-LEVEL EXCEPTION:
    com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe) or version (0034.0000)
        at com.android.dx.cf.direct.DirectClassFile.parse0(DirectClassFile.java:472)
        at com.android.dx.cf.direct.DirectClassFile.parse(DirectClassFile.java:406)
        at com.android.dx.cf.direct.DirectClassFile.parseToInterfacesIfNecessary(DirectClassFile.java:388)
        at com.android.dx.cf.direct.DirectClassFile.getMagic(DirectClassFile.java:251)
        at com.android.dx.command.dexer.Main.processClass(Main.java:665)
        at com.android.dx.command.dexer.Main.processFileBytes(Main.java:634)
        at com.android.dx.command.dexer.Main.access$600(Main.java:78)
        at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:572)
        at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:284)
        at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:166)
        at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)
        at com.android.dx.command.dexer.Main.processOne(Main.java:596)
        at com.android.dx.command.dexer.Main.processAllFiles(Main.java:498)
        at com.android.dx.command.dexer.Main.runMonoDex(Main.java:264)
        at com.android.dx.command.dexer.Main.run(Main.java:230)
        at com.android.dx.command.dexer.Main.main(Main.java:199)
        at com.android.dx.command.Main.main(Main.java:103)
    ...while parsing com/comuf/revonline/bananaquery/BananaInsert.class
    1 error; aborting

The error is bad class file magic (cafebabe) or version (0034.0000).

I builded and execute the application without problems many times in the same day but now this fails everytime with this message.

---

Project SDK is Android API 19 Platform and project level is 1.7.

CompileSDK is 19 and buildToolsVersion is '20.0.0'.

Compile options:

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_7
    targetCompatibility JavaVersion.VERSION_1_7
}

and in dependencies i have:

compile files('libs/bananaquery.jar')

---

The library is build with SDK Android API 19 Platform with project level 1.7.

My .jar file is inside libs/ folder.

I use IntelliJ IDEA 14 Preview, it could be the reason? With IntellIJ IDEA 13 it remains stuck at "Gradle sync"

compile files could be useless since i have compile fileTree(dir: 'libs', include: ['*.jar']) too

Answer 1

my JAVA_HOME variable changed to Java 1.8 and I got this error message when compiling a pure java module as a dependency of my android project.

build.gradle of the java module

apply plugin: 'java'

Solution #1: Quick an dirty

I fixed it by setting my JAVA_HOME back to 1.7:

export JAVA_HOME=`/usr/libexec/java_home -v 1.7`

Solution #2: change compiler version:

change back to 1.7 for this specific module in its build.gradle

apply plugin: 'java'
sourceCompatibility = 1.7
targetCompatibility = 1.7

Answer 2

Ok, my bad.

In the Project SDK section, when you add an Android SDK you should provide the Java SDK and all my Android SDKs uses Java 8 as SDK so it create the class files with the wrong version even if the Project level is 1.7 (i don't know why, i supposed that everything was choosed by Project level).

Now i changed the SDK (the java version "1.x.0" part.)

and it seems to compile fine.

The reason that worked before today was because my SDK was 1.8 and not Android API x

Answer 3

In case people find @Marco Acierno's answer to be a bit unclear, the solution is to ensure you're building with Java 7 and not a higher version.

For Android Studio, change File -> Project Structure -> SDK Location -> JDK Location to jdk1.7.x. For the command line, ensure java -version outputs java version "1.7.x".

Answer 4

Setting JAVA_HOME back to 1.7 worked for me.