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ReflectionUtil.java
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ReflectionUtil.java
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package mezz.jei.util;
import javax.annotation.Nullable;
import java.lang.reflect.Field;
import com.google.common.base.Optional;
import com.google.common.collect.HashBasedTable;
import com.google.common.collect.Table;
public final class ReflectionUtil {
private static final Table<Class, Class, Optional<Field>> CACHE = HashBasedTable.create();
private ReflectionUtil() {
}
@Nullable
public static <T> T getFieldWithClass(final Object object, final Class<T> fieldClass) {
Field field = getField(object, fieldClass);
if (field != null) {
try {
Object fieldValue = field.get(object);
if (fieldClass.isInstance(fieldValue)) {
return fieldClass.cast(fieldValue);
}
} catch (IllegalAccessException ignored) {
}
}
return null;
}
@Nullable
private static Field getField(final Object object, final Class<?> fieldClass) {
Class<?> objectClass = object.getClass();
Optional<Field> cachedField = CACHE.get(fieldClass, objectClass);
if (cachedField != null) {
if (cachedField.isPresent()) {
return cachedField.get();
} else {
return null;
}
}
try {
Field[] fields = objectClass.getDeclaredFields();
for (Field field : fields) {
if (fieldClass.isAssignableFrom(field.getType())) {
if (!field.isAccessible()) {
field.setAccessible(true);
}
CACHE.put(fieldClass, objectClass, Optional.of(field));
return field;
}
}
} catch (SecurityException ignored) {
}
CACHE.put(fieldClass, objectClass, Optional.<Field>absent());
return null;
}
}