com.google.gson.FieldAttributes Maven / Gradle / Ivy
/*
* Copyright (C) 2009 Google Inc.
*
* 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 com.google.gson;
import com.google.gson.internal.$Gson$Preconditions;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.Collection;
/**
* A data object that stores attributes of a field.
*
* This class is immutable; therefore, it can be safely shared across threads.
*
* @author Inderjeet Singh
* @author Joel Leitch
*
* @since 1.4
*/
public final class FieldAttributes {
private final Field field;
/**
* Constructs a Field Attributes object from the {@code f}.
*
* @param f the field to pull attributes from
*/
public FieldAttributes(Field f) {
$Gson$Preconditions.checkNotNull(f);
this.field = f;
}
/**
* @return the declaring class that contains this field
*/
public Class getDeclaringClass() {
return field.getDeclaringClass();
}
/**
* @return the name of the field
*/
public String getName() {
return field.getName();
}
/**
*
For example, assume the following class definition:
*
* public class Foo {
* private String bar;
* private List<String> red;
* }
*
* Type listParameterizedType = new TypeToken<List<String>>() {}.getType();
*
*
* This method would return {@code String.class} for the {@code bar} field and
* {@code listParameterizedType} for the {@code red} field.
*
* @return the specific type declared for this field
*/
public Type getDeclaredType() {
return field.getGenericType();
}
/**
* Returns the {@code Class} object that was declared for this field.
*
*
For example, assume the following class definition:
*
* public class Foo {
* private String bar;
* private List<String> red;
* }
*
*
* This method would return {@code String.class} for the {@code bar} field and
* {@code List.class} for the {@code red} field.
*
* @return the specific class object that was declared for the field
*/
public Class getDeclaredClass() {
return field.getType();
}
/**
* Return the {@code T} annotation object from this field if it exist; otherwise returns
* {@code null}.
*
* @param annotation the class of the annotation that will be retrieved
* @return the annotation instance if it is bound to the field; otherwise {@code null}
*/
public T getAnnotation(Class annotation) {
return field.getAnnotation(annotation);
}
/**
* Return the annotations that are present on this field.
*
* @return an array of all the annotations set on the field
* @since 1.4
*/
public Collection getAnnotations() {
return Arrays.asList(field.getAnnotations());
}
/**
* Returns {@code true} if the field is defined with the {@code modifier}.
*
* This method is meant to be called as:
*
* boolean hasPublicModifier = fieldAttribute.hasModifier(java.lang.reflect.Modifier.PUBLIC);
*
*
* @see java.lang.reflect.Modifier
*/
public boolean hasModifier(int modifier) {
return (field.getModifiers() & modifier) != 0;
}
/**
* Returns the value of the field represented by this {@code Field}, on
* the specified object. The value is automatically wrapped in an
* object if it has a primitive type.
*
* @return the value of the represented field in object
* {@code obj}; primitive values are wrapped in an appropriate
* object before being returned
* @throws IllegalAccessException
* @throws IllegalArgumentException
*/
Object get(Object instance) throws IllegalAccessException {
return field.get(instance);
}
/**
* This is exposed internally only for the removing synthetic fields from the JSON output.
*
* @return true if the field is synthetic; otherwise false
*/
boolean isSynthetic() {
return field.isSynthetic();
}
}