FieldDescriptor.java
/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package androidx.test.espresso.remote;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import android.support.annotation.NonNull;
import androidx.test.espresso.remote.annotation.RemoteMsgField;
import com.google.common.collect.ImmutableList;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.util.List;
import java.util.TreeMap;
/**
* Provides additional meta data about a {@link Field} declared in a class.
*
* <p>The data provided here is used at runtime to reflectively access fields that require proto
* serialization.
*/
public final class FieldDescriptor {
public final Class<?> fieldType;
public final String fieldName;
public final int order;
private FieldDescriptor(@NonNull Class<?> fieldType, @NonNull String fieldName, int order) {
this.fieldType = checkNotNull(fieldType, "fieldType cannot be null!");
this.fieldName = checkNotNull(fieldName, "fieldName cannot be null!");
checkState(order >= 0, "Field order must be greater then or equal to 0!");
this.order = order;
}
/**
* Creates a {@link FieldDescriptor} instance.
*
* @param fieldType the type of the field
* @param fieldName the name of the field as declared in the class
* @param order the declared order of the field, order values need to start with 0
*/
public static FieldDescriptor of(
@NonNull Class<?> fieldType, @NonNull String fieldName, int order) {
return new FieldDescriptor(fieldType, fieldName, order);
}
/**
* Creates a {@link FieldDescriptor} instance from a {@link Field} and {@link Annotation}.
*
* @param field a {@link Field} object
* @param remoteMsgFieldAnnotation an {@link Annotation} attached to {@code field}
*/
static FieldDescriptor of(
@NonNull Field field, @NonNull RemoteMsgField remoteMsgFieldAnnotation) {
checkNotNull(field, "field cannot be null");
checkNotNull(remoteMsgFieldAnnotation, "remoteMsgFieldAnnotation cannot be null");
return of(field.getType(), field.getName(), remoteMsgFieldAnnotation.order());
}
static List<FieldDescriptor> getFieldDescriptorsFromAnnotation(
Class<?> clazz, Class<RemoteMsgField> annotation) {
TreeMap<Integer, FieldDescriptor> targetFields = new TreeMap<>();
Field[] declaredFields = clazz.getDeclaredFields();
for (Field field : declaredFields) {
if (field.isAnnotationPresent(annotation)) {
RemoteMsgField remoteMsgFieldAnnotation = field.getAnnotation(annotation);
int order = remoteMsgFieldAnnotation.order();
if (targetFields.containsKey(order)) {
throw new IllegalStateException(
String.format("Duplicate field order %s for field %s", order, field.getName()));
}
targetFields.put(order, of(field, remoteMsgFieldAnnotation));
}
}
return ImmutableList.copyOf(targetFields.values());
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
FieldDescriptor that = (FieldDescriptor) o;
if (order != that.order) {
return false;
}
if (fieldType != null ? !fieldType.equals(that.fieldType) : that.fieldType != null) {
return false;
}
return fieldName != null ? fieldName.equals(that.fieldName) : that.fieldName == null;
}
@Override
public int hashCode() {
int result = fieldType != null ? fieldType.hashCode() : 0;
result = 31 * result + (fieldName != null ? fieldName.hashCode() : 0);
result = 31 * result + order;
return result;
}
}