com.avaje.ebean.util.ClassUtil Maven / Gradle / Ivy
package com.avaje.ebean.util;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Arrays;
/**
* Helper to find classes taking into account the context class loader.
*/
public class ClassUtil {
/**
* Returns the raw type for the 2nd generic parameter for a subclass.
*/
public static Class getSecondArgumentType(Class subclass) {
Type[] typeArguments = getSuperclassTypeParameter(subclass);
if (typeArguments.length != 2) {
throw new IllegalArgumentException("Expected type with 2 generic argument types but got "
+ typeArguments.length + " - " + Arrays.toString(typeArguments));
}
return getRawType(typeArguments[1]);
}
static Type[] getSuperclassTypeParameter(Class subclass) {
Type superclass = subclass.getGenericSuperclass();
if (superclass instanceof Class) {
throw new RuntimeException("Missing generics type parameters on subclass " + subclass);
}
return ((ParameterizedType) superclass).getActualTypeArguments();
}
private static Class getRawType(Type type) {
if (type instanceof Class) {
return (Class) type;
} else if (type instanceof ParameterizedType) {
ParameterizedType parameterizedType = (ParameterizedType) type;
Type rawType = parameterizedType.getRawType();
if (rawType instanceof Class) {
return (Class) rawType;
}
}
throw new RuntimeException("Unable to obtain raw class type from " + type);
}
}