/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
/*
* Copyright (C) 2008 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 java.lang.reflect;
import com.android.dex.Dex;
import java.lang.annotation.Annotation;
import java.util.Comparator;
import java.util.List;
import libcore.reflect.AnnotationAccess;
import libcore.reflect.GenericSignatureParser;
import libcore.reflect.Types;
/**
* This class represents a field. Information about the field can be accessed,
* and the field's value can be accessed dynamically.
*/
public final class Field extends AccessibleObject implements Member {
/**
* Orders fields by their name and declaring class.
*
* @hide
*/
public static final Comparator<Field> ORDER_BY_NAME_AND_DECLARING_CLASS
= new Comparator<Field>() {
@Override public int compare(Field a, Field b) {
if (a == b) {
return 0;
}
int comparison = a.getName().compareTo(b.getName());
if (comparison != 0) {
return comparison;
}
Class<?> aType = a.getDeclaringClass();
Class<?> bType = b.getDeclaringClass();
if (aType == bType) {
return 0;
} else {
return aType.getName().compareTo(bType.getName());
}
}
};
private int accessFlags;
private Class<?> declaringClass;
private int dexFieldIndex;
private int offset;
private Class<?> type;
private Field() {
}
/**
* Returns the modifiers for this field. The {@link Modifier} class should
* be used to decode the result.
*
* @return the modifiers for this field
* @see Modifier
*/
@Override public int getModifiers() {
return accessFlags & 0xffff; // mask out bits not used by Java
}
/**
* Indicates whether or not this field is an enumeration constant.
*
* @return {@code true} if this field is an enumeration constant, {@code
* false} otherwise
*/
public boolean isEnumConstant() {
return (accessFlags & Modifier.ENUM) != 0;
}
/**
* Indicates whether or not this field is synthetic.
*
* @return {@code true} if this field is synthetic, {@code false} otherwise
*/
@Override public boolean isSynthetic() {
return (accessFlags & Modifier.SYNTHETIC) != 0;
}
/**
* Returns the name of this field.
*
* @return the name of this field
*/
@Override public String getName() {
if (dexFieldIndex == -1) {
// Proxy classes have 1 synthesized static field with no valid dex index.
if (!declaringClass.isProxy()) {
throw new AssertionError();
}
return "throws";
}
Dex dex = declaringClass.getDex();
int nameIndex = dex.nameIndexFromFieldIndex(dexFieldIndex);
return declaringClass.getDexCacheString(dex, nameIndex);
}
@Override public Class<?> getDeclaringClass() {
return declaringClass;
}
/**
* Return the {@link Class} associated with the type of this field.
*
* @return the type of this field
*/
public Class<?> getType() {
return type;
}
/**
* Returns the index of this field's ID in its dex file.
*
* @hide
*/
public int getDexFieldIndex() {
return dexFieldIndex;
}
/**
* Returns the offset of the field within an instance, or for static fields, the class.
*
* @hide
*/
public int getOffset() {
return offset;
}
/**
* {@inheritDoc}
*
* <p>Equivalent to {@code getDeclaringClass().getName().hashCode() ^ getName().hashCode()}.
*/
@Override public int hashCode() {
return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
}
/**
* Returns true if {@code other} has the same declaring class, name and type
* as this field.
*/
@Override public boolean equals(Object other) {
if (!(other instanceof Field)) {
return false;
}
// Given same declaring class and offset, it must be the same field since no two distinct
// fields can have the same offset.
Field field = (Field)other;
return this.declaringClass == field.declaringClass && this.offset == field.offset;
}
/**
* Returns the string representation of this field, including the field's
* generic type.
*
* @return the string representation of this field
*/
public String toGenericString() {
StringBuilder sb = new StringBuilder(80);
// Limit modifier bits to the ones that toStringGeneric should return for fields.
String modifiers = Modifier.getDeclarationFieldModifiers(getModifiers());
// append modifiers if any
if (!modifiers.isEmpty()) {
sb.append(modifiers).append(' ');
}
// append generic type
Types.appendGenericType(sb, getGenericType());
sb.append(' ');
// append full field name
sb.append(getDeclaringClass().getName()).append('.').append(getName());
return sb.toString();
}
/**
* Returns the generic type of this field.
*
* @return the generic type
* @throws GenericSignatureFormatError
* if the generic field signature is invalid
* @throws TypeNotPresentException
* if the generic type points to a missing type
* @throws MalformedParameterizedTypeException
* if the generic type points to a type that cannot be
* instantiated for some reason
*/
public Type getGenericType() {
String signatureAttribute = AnnotationAccess.getSignature(this);
Class<?> declaringClass = getDeclaringClass();
ClassLoader cl = declaringClass.getClassLoader();
GenericSignatureParser parser = new GenericSignatureParser(cl);
parser.parseForField(declaringClass, signatureAttribute);
Type genericType = parser.fieldType;
if (genericType == null) {
genericType = getType();
}
return genericType;
}
/**
* Returns the constructor's signature in non-printable form. This is called
* (only) from IO native code and needed for deriving the serialVersionUID
* of the class
*/
@SuppressWarnings("unused")
private String getSignature() {
return Types.getSignature(getType());
}
@Override public Annotation[] getDeclaredAnnotations() {
List<Annotation> result = AnnotationAccess.getDeclaredAnnotations(this);
return result.toArray(new Annotation[result.size()]);
}
@Override public <A extends Annotation> A getAnnotation(Class<A> annotationType) {
if (annotationType == null) {
throw new NullPointerException("annotationType == null");
}
return AnnotationAccess.getDeclaredAnnotation(this, annotationType);
}
@Override public boolean isAnnotationPresent(Class<? extends Annotation> annotationType) {
if (annotationType == null) {
throw new NullPointerException("annotationType == null");
}
return AnnotationAccess.isDeclaredAnnotationPresent(this, annotationType);
}
/**
* Returns the value of the field in the specified object. This reproduces
* the effect of {@code object.fieldName}
*
* <p>If the type of this field is a primitive type, the field value is
* automatically boxed.
*
* <p>If this field is static, the object argument is ignored.
* Otherwise, if the object is null, a NullPointerException is thrown. If
* the object is not an instance of the declaring class of the method, an
* IllegalArgumentException is thrown.
*
* <p>If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* @param object
* the object to access
* @return the field value, possibly boxed
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native Object get(Object object)
throws IllegalAccessException, IllegalArgumentException;
/**
* Returns the value of the field in the specified object as a {@code
* boolean}. This reproduces the effect of {@code object.fieldName}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* @param object
* the object to access
* @return the field value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native boolean getBoolean(Object object)
throws IllegalAccessException, IllegalArgumentException;
/**
* Returns the value of the field in the specified object as a {@code byte}.
* This reproduces the effect of {@code object.fieldName}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* @param object
* the object to access
* @return the field value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native byte getByte(Object object)
throws IllegalAccessException, IllegalArgumentException;
/**
* Returns the value of the field in the specified object as a {@code char}.
* This reproduces the effect of {@code object.fieldName}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* @param object
* the object to access
* @return the field value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native char getChar(Object object)
throws IllegalAccessException, IllegalArgumentException;
/**
* Returns the value of the field in the specified object as a {@code
* double}. This reproduces the effect of {@code object.fieldName}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* @param object
* the object to access
* @return the field value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native double getDouble(Object object)
throws IllegalAccessException, IllegalArgumentException;
/**
* Returns the value of the field in the specified object as a {@code float}
* . This reproduces the effect of {@code object.fieldName}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* @param object
* the object to access
* @return the field value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native float getFloat(Object object)
throws IllegalAccessException, IllegalArgumentException;
/**
* Returns the value of the field in the specified object as an {@code int}.
* This reproduces the effect of {@code object.fieldName}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* @param object
* the object to access
* @return the field value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native int getInt(Object object)
throws IllegalAccessException, IllegalArgumentException;
/**
* Returns the value of the field in the specified object as a {@code long}.
* This reproduces the effect of {@code object.fieldName}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* @param object
* the object to access
* @return the field value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native long getLong(Object object)
throws IllegalAccessException, IllegalArgumentException;
/**
* Returns the value of the field in the specified object as a {@code short}
* . This reproduces the effect of {@code object.fieldName}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* @param object
* the object to access
* @return the field value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native short getShort(Object object)
throws IllegalAccessException, IllegalArgumentException;
/**
* Sets the value of the field in the specified object to the value. This
* reproduces the effect of {@code object.fieldName = value}
*
* <p>If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
*
* <p>If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
*
* <p>If the field type is a primitive type, the value is automatically
* unboxed. If the unboxing fails, an IllegalArgumentException is thrown. If
* the value cannot be converted to the field type via a widening
* conversion, an IllegalArgumentException is thrown.
*
* @param object
* the object to access
* @param value
* the new value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native void set(Object object, Object value)
throws IllegalAccessException, IllegalArgumentException;
/**
* Sets the value of the field in the specified object to the {@code
* boolean} value. This reproduces the effect of {@code object.fieldName =
* value}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
* <p>
* If the value cannot be converted to the field type via a widening
* conversion, an IllegalArgumentException is thrown.
*
* @param object
* the object to access
* @param value
* the new value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native void setBoolean(Object object, boolean value)
throws IllegalAccessException, IllegalArgumentException;
/**
* Sets the value of the field in the specified object to the {@code byte}
* value. This reproduces the effect of {@code object.fieldName = value}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
* <p>
* If the value cannot be converted to the field type via a widening
* conversion, an IllegalArgumentException is thrown.
*
* @param object
* the object to access
* @param value
* the new value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native void setByte(Object object, byte value)
throws IllegalAccessException, IllegalArgumentException;
/**
* Sets the value of the field in the specified object to the {@code char}
* value. This reproduces the effect of {@code object.fieldName = value}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
* <p>
* If the value cannot be converted to the field type via a widening
* conversion, an IllegalArgumentException is thrown.
*
* @param object
* the object to access
* @param value
* the new value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native void setChar(Object object, char value)
throws IllegalAccessException, IllegalArgumentException;
/**
* Sets the value of the field in the specified object to the {@code double}
* value. This reproduces the effect of {@code object.fieldName = value}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
* <p>
* If the value cannot be converted to the field type via a widening
* conversion, an IllegalArgumentException is thrown.
*
* @param object
* the object to access
* @param value
* the new value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native void setDouble(Object object, double value)
throws IllegalAccessException, IllegalArgumentException;
/**
* Sets the value of the field in the specified object to the {@code float}
* value. This reproduces the effect of {@code object.fieldName = value}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
* <p>
* If the value cannot be converted to the field type via a widening
* conversion, an IllegalArgumentException is thrown.
*
* @param object
* the object to access
* @param value
* the new value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native void setFloat(Object object, float value)
throws IllegalAccessException, IllegalArgumentException;
/**
* Set the value of the field in the specified object to the {@code int}
* value. This reproduces the effect of {@code object.fieldName = value}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
* <p>
* If the value cannot be converted to the field type via a widening
* conversion, an IllegalArgumentException is thrown.
*
* @param object
* the object to access
* @param value
* the new value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native void setInt(Object object, int value)
throws IllegalAccessException, IllegalArgumentException;
/**
* Sets the value of the field in the specified object to the {@code long}
* value. This reproduces the effect of {@code object.fieldName = value}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
* <p>
* If the value cannot be converted to the field type via a widening
* conversion, an IllegalArgumentException is thrown.
*
* @param object
* the object to access
* @param value
* the new value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native void setLong(Object object, long value)
throws IllegalAccessException, IllegalArgumentException;
/**
* Sets the value of the field in the specified object to the {@code short}
* value. This reproduces the effect of {@code object.fieldName = value}
* <p>
* If this field is static, the object argument is ignored.
* Otherwise, if the object is {@code null}, a NullPointerException is
* thrown. If the object is not an instance of the declaring class of the
* method, an IllegalArgumentException is thrown.
* <p>
* If this Field object is enforcing access control (see AccessibleObject)
* and this field is not accessible from the current context, an
* IllegalAccessException is thrown.
* <p>
* If the value cannot be converted to the field type via a widening
* conversion, an IllegalArgumentException is thrown.
*
* @param object
* the object to access
* @param value
* the new value
* @throws NullPointerException
* if the object is {@code null} and the field is non-static
* @throws IllegalArgumentException
* if the object is not compatible with the declaring class
* @throws IllegalAccessException
* if this field is not accessible
*/
public native void setShort(Object object, short value)
throws IllegalAccessException, IllegalArgumentException;
/**
* Returns a string containing a concise, human-readable description of this
* field.
* <p>
* The format of the string is:
* <ol>
* <li>modifiers (if any)
* <li>type
* <li>declaring class name
* <li>'.'
* <li>field name
* </ol>
* <p>
* For example: {@code public static java.io.InputStream
* java.lang.System.in}
*
* @return a printable representation for this field
*/
@Override
public String toString() {
StringBuilder result = new StringBuilder(
Modifier.getDeclarationFieldModifiers(getModifiers()));
if (result.length() != 0) {
result.append(' ');
}
Types.appendTypeName(result, getType());
result.append(' ');
result.append(getDeclaringClass().getName());
result.append('.');
result.append(getName());
return result.toString();
}
}