org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15

Question 1

The "offical answer" is that Tomcat 7 runs on Java 8, see http://tomcat.apache.org/whichversion.html ("Java version 6 and later").

However, if annotation scanning is enabled (metadata-complete="true" in web.xml) there are some issues due to BCEL (not able to process the new Java 8 byte codes). You will get exceptions like (at least with Tomcat 7.0.28):

SEVERE: Unable to process Jar entry [jdk/nashorn/internal/objects/NativeString.class] from Jar [jar:file:/usr/lib/jvm/jdk1.8.0_5/jre/lib/ext/nashorn.jar!/] for annotations
org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15
    at org.apache.tomcat.util.bcel.classfile.Constant.readConstant(Constant.java:131)

If not using annotation scanning, everything works fine, starting release 7.0.53 (updated compiler with better Java 8 support).

(UPDATE 2014-10-17) If your are using annotation scanning and your own code is not Java 8 based, another solution is to add the following line in /etc/tomcat7/catalina.properties (text added after "ant-launcher.jar" so part of property tomcat.util.scan.DefaultJarScanner.jarsToSkip):

junit.jar,junit-*.jar,ant-launcher.jar,\
jfxrt.jar,nashorn.jar

Tested with Tomcat 7.0.28 and Oracle JDK 8_25 on Debian 7.6.

Question 2

This was a Tomcat bug that resurfaced again with the Java 9 bytecode. The exact versions which fix this (for both Java 8/9 bytecode) are:

trunk for 9.0.0.M18 onwards
8.5.x for 8.5.12 onwards
8.0.x for 8.0.42 onwards
7.0.x for 7.0.76 onwards

Question 3

Update to Tomcat 7.0.58 (or newer).

See: https://bz.apache.org/bugzilla/show_bug.cgi?id=57173#c16

The performance improvement that triggered this regression has been reverted from from trunk, 8.0.x (for 8.0.16 onwards) and 7.0.x (for 7.0.58 onwards) and will not be reapplied.

Question 4

I've had the same problem when running my spring boot application with tomcat7:run

It gives error with the following dependency in maven pom.xml:

    <dependency>
        <groupId>org.junit.vintage</groupId>
        <artifactId>junit-vintage-engine</artifactId>
    </dependency>

SEVERE: Unable to process Jar entry [module-info.class] from Jar [jar:file:/.m2/repository/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0.jar!/] for annotations
org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 19

Jul 09, 2020 1:28:09 PM org.apache.catalina.startup.ContextConfig processAnnotationsJar
SEVERE: Unable to process Jar entry [module-info.class] from Jar [jar:file:/.m2/repository/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0.jar!/] for annotations
org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 19

But when I correctly specify it in test scope, it does not give error:

    <dependency>
        <groupId>org.junit.vintage</groupId>
        <artifactId>junit-vintage-engine</artifactId>
        <scope>test</scope>
    </dependency>

Question 5

This issue is happening because you have installed jre1.8.0_101-1.8.0_101-fcs.i58.rpm as well jdk-1.7.0_80-fcs.x86_64.rpm. so just uninstall your jre rpm & restart your application. It should work out.

Question 6

To me, upgrading bcel to 6.0 fixed the problem.

Question 7

Unable to process Jar entry [module-info.class] from Jar [jar:file:/xxxxxxxx/lombok-1.18.4.jar!/] for annotations
org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 19

1.update and append below argument in <root or instance tomcat folder>/conf/catalina.properties

org.apache.catalina.startup.ContextConfig.jarsToSkip=...,lombok-1.18.4.jar

2.clean and deploy the to-be-published project.

Question 8

For me it worked, by removing the jars in question from the war. With Maven, I just had to exclude for example

    <dependency>
        <groupId>org.jboss.resteasy</groupId>
        <artifactId>resteasy-jaxb-provider</artifactId>
        <version>${resteasy.version}</version>
        <exclusions>
            <exclusion>
                <groupId>com.sun.istack</groupId>
                <artifactId>istack-commons-runtime</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.jvnet.staxex</groupId>
                <artifactId>stax-ex</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.glassfish.jaxb</groupId>
                <artifactId>txw2</artifactId>
            </exclusion>
            <exclusion>
                <groupId>com.sun.xml.fastinfoset</groupId>
                <artifactId>FastInfoset</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

Question 9

I faced this issue with tomcat 7 + jdk 1.8

with java 1.7 and lower versions it's working fine.

window -> preferences -> java -> installed jre

in my case I changed jre1.8 to JDK 1.7

and accordingly modify project facet , select same java version as it's there in selected Installed JRE.

Question 10

I got similar error (org.aspectj.apache.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15) while using aspectj 1.8.13. Solution was to align all compilation into jdk 8 and being careful not to put aspectj library's (1.6.13 for instance) other versions to buildpath/classpath.