io.ebeaninternal.api.ClassUtil Maven / Gradle / Ivy
package io.ebeaninternal.api;
/**
* Helper to find classes taking into account the context class loader.
*/
public class ClassUtil {
/**
* Return a new instance of the class using the default constructor.
*/
public static Object newInstance(String className) {
try {
Class cls = forName(className);
return cls.newInstance();
} catch (Exception e) {
String msg = "Error constructing " + className;
throw new IllegalArgumentException(msg, e);
}
}
/**
* Load a class taking into account a context class loader (if present).
*/
public static Class forName(String name) throws ClassNotFoundException {
return new ClassLoadContext().forName(name);
}
/**
* Helper to wrap the context and caller classLoaders (to use/try both).
*/
static class ClassLoadContext {
private final ClassLoader contextLoader;
private final ClassLoader callerLoader;
ClassLoadContext() {
this.callerLoader = ClassUtil.class.getClassLoader();
this.contextLoader = contextLoader();
}
ClassLoader contextLoader() {
ClassLoader loader = Thread.currentThread().getContextClassLoader();
return (loader != null) ? loader : callerLoader;
}
public Class forName(String name) throws ClassNotFoundException {
try {
return Class.forName(name, true, contextLoader);
} catch (ClassNotFoundException e) {
if (callerLoader == contextLoader) {
throw e;
} else {
return Class.forName(name, true, callerLoader);
}
}
}
}
}