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package java_integration.fixtures;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.lang.reflect.Array;
import java.util.Collection;
import java.util.ArrayList;
import java.util.Arrays;
public abstract class Reflector {
public static Object invoke(final Object obj, final Method method) throws Exception {
if ( method.isVarArgs() ) {
final Class type = method.getParameterTypes()[0].getComponentType();
Object array = Array.newInstance(type, 0);
return method.invoke(obj, array);
}
return method.invoke(obj);
}
public static Object invoke(final Object obj, final Method method, Object arg) throws Exception {
if ( method.isVarArgs() && ! arg.getClass().isArray() ) {
final Class type = method.getParameterTypes()[0].getComponentType();
Object[] array = (Object[]) Array.newInstance(type, 1);
array[0] = arg;
return method.invoke(obj, (Object) array);
}
return method.invoke(obj, arg);
}
public static Object invoke(final Object obj, final Class<?> klass, final String method) throws Exception {
Method instanceMethod = klass.getMethod(method, (Class[]) null);
return instanceMethod.invoke(obj, (Object[]) null);
}
public static Object invoke(final Object obj, final String method) throws Exception {
return invoke(obj, obj.getClass(), method);
}
public static Object invokeMatch(final Object obj, final String method, final Object... args) throws Exception {
final Method[] methods = obj.getClass().getMethods();
ArrayList<Method> matchedMethods = new ArrayList<Method>();
for ( Method m : methods ) {
if ( method.equals(m.getName()) ) {
if ( m.isVarArgs() ) matchedMethods.add(m);
else {
if (m.getParameterTypes().length == args.length) {
matchedMethods.add(m);
}
}
}
}
if ( matchedMethods.isEmpty() ) {
throw new IllegalArgumentException("no methods of name " + method + " matched in " + obj.getClass());
}
if ( matchedMethods.size() > 1 ) {
throw new IllegalArgumentException("multiple methods matched for name " + method + " and arguments " + Arrays.toString(args));
}
return matchedMethods.get(0).invoke(obj, args);
}
public static Method resolveMethod(final Object obj, final String method, final Class... types) throws Exception {
final Method[] methods = obj.getClass().getMethods();
ArrayList<Method> matchedMethods = new ArrayList<Method>();
for ( Method m : methods ) {
if ( method.equals(m.getName()) ) {
if ( Arrays.equals(m.getParameterTypes(), types) ) {
matchedMethods.add(m);
}
}
}
if ( matchedMethods.isEmpty() ) {
throw new IllegalArgumentException("no methods of name " + method + " matched in " + obj.getClass());
}
if ( matchedMethods.size() > 1 ) {
throw new IllegalArgumentException("multiple methods matched for name " + method + " and param types " + Arrays.toString(types));
}
return matchedMethods.get(0);
}
public static Collection<Method> findMethods(final Object obj, final String method) throws Exception {
final Method[] methods = obj.getClass().getMethods();
ArrayList<Method> matchedMethods = new ArrayList<Method>();
for ( Method m : methods ) {
if ( method.equals(m.getName()) ) {
matchedMethods.add(m);
}
}
return matchedMethods;
}
public static <A extends Annotation> A getDeclaredAnnotation(Class<?> clazz,
Class<A> annotationType) {
for (Annotation a : clazz.getDeclaredAnnotations()) {
if (annotationType.isAssignableFrom(a.annotationType())) {
return (A) a;
}
}
return null;
}
}
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