I have created a Maven project in Intellij IDEA to illustrate the issue; the code seeks to use the extCos scanner classes to find all classes implementing an interface.
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>TestComponentScanner</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>17</maven.compiler.source>
<maven.compiler.target>17</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>net.sf.extcos</groupId>
<artifactId>extcos</artifactId>
<version>0.4b</version>
<exclusions>
<exclusion>
<groupId>org.ow2.asm</groupId>
<artifactId>asm-all</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.ow2.asm</groupId>
<artifactId>asm</artifactId>
<version>9.2</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.36</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-jdk14</artifactId>
<version>1.7.36</version>
</dependency>
</dependencies>
</project>
The ExampleComponentScanner class
package com.example;
import java.util.HashSet;
import java.util.Set;
import net.sf.extcos.ComponentQuery;
import net.sf.extcos.ComponentScanner;
public class ExampleComponentScanner {
public Set<Class<?>> getImplementingClasses(){
Set<Class<?>> classes = new HashSet<Class<?>>();
ComponentScanner scanner = new ComponentScanner();
Set<Class<?>> finalClasses = classes;
classes = scanner.getClasses(new ComponentQuery() {
@Override
protected void query() {
select().
from("com.example").
returning(allImplementing(ExampleInterface.class));
}
});
return classes;
}
public static void main(String[] args){
ExampleComponentScanner exConScan = new ExampleComponentScanner();
Set<Class<?>> setClasses = exConScan.getImplementingClasses();
for (Class exIntCl:setClasses) {
System.out.println(exIntCl.getName());
System.out.println(", ");
}
}
}
ExampleInterface
package com.example;
public interface ExampleInterface {
public default String getInterfaceName(){
return null;
}
}
The implementing class
package com.example;
public class ExampleImplementer001 implements ExampleInterface{
}
This project runs as expected when built using JDK 1.8. It builds successfully with JDK 11 and JDK 17 as well, but when the ExampleComponentScanner class built with either of the newer Java versions (11 and 17) is executed, it throws the following exception:
C:\JDK\BellSoft\LibericaJDK-17-Full\bin\java.exe "-javaagent:C:\IntelliJ IDEA Community Edition 2020.3.3\lib\idea_rt.jar=64764:C:\IntelliJ IDEA Community Edition 2020.3.3\bin" -Dfile.encoding=UTF-8 -classpath C:\Users\absoluteBeginner\IdeaProjects\TestComponentScanner\target\classes;C:\Users\absoluteBeginner\.m2\repository\net\sf\extcos\extcos\0.4b\extcos-0.4b.jar;C:\Users\absoluteBeginner\.m2\repository\org\ow2\asm\asm\5.0\asm-5.0.jar;C:\Users\absoluteBeginner\.m2\repository\org\slf4j\slf4j-api\1.7.36\slf4j-api-1.7.36.jar;C:\Users\absoluteBeginner\.m2\repository\org\slf4j\slf4j-jdk14\1.7.36\slf4j-jdk14-1.7.36.jar com.example.ExampleComponentScanner
Exception in thread "eXtcos managed thread 1" java.lang.IllegalArgumentException
at org.objectweb.asm.ClassReader.<init>(Unknown Source)
at org.objectweb.asm.ClassReader.<init>(Unknown Source)
at net.sf.extcos.internal.JavaResourceAccessor.readClassData(JavaResourceAccessor.java:362)
at net.sf.extcos.internal.JavaResourceAccessor.setResourceUrl(JavaResourceAccessor.java:333)
at net.sf.extcos.internal.URLResource.getResourceAccessor(URLResource.java:93)
at net.sf.extcos.internal.URLResource.isClass(URLResource.java:126)
at net.sf.extcos.internal.RootFilter.filter(RootFilter.java:22)
at net.sf.extcos.internal.AbstractChainedFilter.filter(AbstractChainedFilter.java:89)
at net.sf.extcos.internal.ThreadingFilterInterceptor$1.run(ThreadingFilterInterceptor.java:48)
at java.base/java.lang.Thread.run(Thread.java:833)
I am using Bellsoft's Liberica JDK since I also need to integrate some JavaFX code.