JDK8/Java8源码在线阅读
/*
* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.reflect.annotation;
import java.lang.annotation.*;
import java.util.*;
import java.nio.ByteBuffer;
import java.nio.BufferUnderflowException;
import java.lang.reflect.*;
import java.security.AccessController;
import java.security.PrivilegedAction;
import sun.reflect.ConstantPool;
import sun.reflect.generics.parser.SignatureParser;
import sun.reflect.generics.tree.TypeSignature;
import sun.reflect.generics.factory.GenericsFactory;
import sun.reflect.generics.factory.CoreReflectionFactory;
import sun.reflect.generics.visitor.Reifier;
import sun.reflect.generics.scope.ClassScope;
/**
* Parser for Java programming language annotations. Translates
* annotation byte streams emitted by compiler into annotation objects.
*
* @author Josh Bloch
* @since 1.5
*/
public class AnnotationParser {
/**
* Parses the annotations described by the specified byte array.
* resolving constant references in the specified constant pool.
* The array must contain an array of annotations as described
* in the RuntimeVisibleAnnotations_attribute:
*
* u2 num_annotations;
* annotation annotations[num_annotations];
*
* @throws AnnotationFormatError if an annotation is found to be
* malformed.
*/
public static Map<Class<? extends Annotation>, Annotation> parseAnnotations(
byte[] rawAnnotations,
ConstantPool constPool,
Class<?> container) {
if (rawAnnotations == null)
return Collections.emptyMap();
try {
return parseAnnotations2(rawAnnotations, constPool, container, null);
} catch(BufferUnderflowException e) {
throw new AnnotationFormatError("Unexpected end of annotations.");
} catch(IllegalArgumentException e) {
// Type mismatch in constant pool
throw new AnnotationFormatError(e);
}
}
/**
* Like {@link #parseAnnotations(byte[], sun.reflect.ConstantPool, Class)}
* with an additional parameter {@code selectAnnotationClasses} which selects the
* annotation types to parse (other than selected are quickly skipped).<p>
* This method is only used to parse select meta annotations in the construction
* phase of {@link AnnotationType} instances to prevent infinite recursion.
*
* @param selectAnnotationClasses an array of annotation types to select when parsing
*/
@SafeVarargs
@SuppressWarnings("varargs") // selectAnnotationClasses is used safely
static Map<Class<? extends Annotation>, Annotation> parseSelectAnnotations(
byte[] rawAnnotations,
ConstantPool constPool,
Class<?> container,
Class<? extends Annotation> ... selectAnnotationClasses) {
if (rawAnnotations == null)
return Collections.emptyMap();
try {
return parseAnnotations2(rawAnnotations, constPool, container, selectAnnotationClasses);
} catch(BufferUnderflowException e) {
throw new AnnotationFormatError("Unexpected end of annotations.");
} catch(IllegalArgumentException e) {
// Type mismatch in constant pool
throw new AnnotationFormatError(e);
}
}
private static Map<Class<? extends Annotation>, Annotation> parseAnnotations2(
byte[] rawAnnotations,
ConstantPool constPool,
Class<?> container,
Class<? extends Annotation>[] selectAnnotationClasses) {
Map<Class<? extends Annotation>, Annotation> result =
new LinkedHashMap<Class<? extends Annotation>, Annotation>();
ByteBuffer buf = ByteBuffer.wrap(rawAnnotations);
int numAnnotations = buf.getShort() & 0xFFFF;
for (int i = 0; i < numAnnotations; i++) {
Annotation a = parseAnnotation2(buf, constPool, container, false, selectAnnotationClasses);
if (a != null) {
Class<? extends Annotation> klass = a.annotationType();
if (AnnotationType.getInstance(klass).retention() == RetentionPolicy.RUNTIME &&
result.put(klass, a) != null) {
throw new AnnotationFormatError(
"Duplicate annotation for class: "+klass+": " + a);
}
}
}
return result;
}
/**
* Parses the parameter annotations described by the specified byte array.
* resolving constant references in the specified constant pool.
* The array must contain an array of annotations as described
* in the RuntimeVisibleParameterAnnotations_attribute:
*
* u1 num_parameters;
* {
* u2 num_annotations;
* annotation annotations[num_annotations];
* } parameter_annotations[num_parameters];
*
* Unlike parseAnnotations, rawAnnotations must not be null!
* A null value must be handled by the caller. This is so because
* we cannot determine the number of parameters if rawAnnotations
* is null. Also, the caller should check that the number
* of parameters indicated by the return value of this method
* matches the actual number of method parameters. A mismatch
* indicates that an AnnotationFormatError should be thrown.
*
* @throws AnnotationFormatError if an annotation is found to be
* malformed.
*/
public static Annotation[][] parseParameterAnnotations(
byte[] rawAnnotations,
ConstantPool constPool,
Class<?> container) {
try {
return parseParameterAnnotations2(rawAnnotations, constPool, container);
} catch(BufferUnderflowException e) {
throw new AnnotationFormatError(
"Unexpected end of parameter annotations.");
} catch(IllegalArgumentException e) {
// Type mismatch in constant pool
throw new AnnotationFormatError(e);
}
}
private static Annotation[][] parseParameterAnnotations2(
byte[] rawAnnotations,
ConstantPool constPool,
Class<?> container) {
ByteBuffer buf = ByteBuffer.wrap(rawAnnotations);
int numParameters = buf.get() & 0xFF;
Annotation[][] result = new Annotation[numParameters][];
for (int i = 0; i < numParameters; i++) {
int numAnnotations = buf.getShort() & 0xFFFF;
List<Annotation> annotations =
new ArrayList<Annotation>(numAnnotations);
for (int j = 0; j < numAnnotations; j++) {
Annotation a = parseAnnotation(buf, constPool, container, false);
if (a != null) {
AnnotationType type = AnnotationType.getInstance(
a.annotationType());
if (type.retention() == RetentionPolicy.RUNTIME)
annotations.add(a);
}
}
result[i] = annotations.toArray(EMPTY_ANNOTATIONS_ARRAY);
}
return result;
}
private static final Annotation[] EMPTY_ANNOTATIONS_ARRAY =
new Annotation[0];
/**
* Parses the annotation at the current position in the specified
* byte buffer, resolving constant references in the specified constant
* pool. The cursor of the byte buffer must point to an "annotation
* structure" as described in the RuntimeVisibleAnnotations_attribute:
*
* annotation {
* u2 type_index;
* u2 num_member_value_pairs;
* { u2 member_name_index;
* member_value value;
* } member_value_pairs[num_member_value_pairs];
* }
* }
*
* Returns the annotation, or null if the annotation's type cannot
* be found by the VM, or is not a valid annotation type.
*
* @param exceptionOnMissingAnnotationClass if true, throw
* TypeNotPresentException if a referenced annotation type is not
* available at runtime
*/
static Annotation parseAnnotation(ByteBuffer buf,
ConstantPool constPool,
Class<?> container,
boolean exceptionOnMissingAnnotationClass) {
return parseAnnotation2(buf, constPool, container, exceptionOnMissingAnnotationClass, null);
}
@SuppressWarnings("unchecked")
private static Annotation parseAnnotation2(ByteBuffer buf,
ConstantPool constPool,
Class<?> container,
boolean exceptionOnMissingAnnotationClass,
Class<? extends Annotation>[] selectAnnotationClasses) {
int typeIndex = buf.getShort() & 0xFFFF;
Class<? extends Annotation> annotationClass = null;
String sig = "[unknown]";
try {
try {
sig = constPool.getUTF8At(typeIndex);
annotationClass = (Class<? extends Annotation>)parseSig(sig, container);
} catch (IllegalArgumentException ex) {
// support obsolete early jsr175 format class files
annotationClass = (Class<? extends Annotation>)constPool.getClassAt(typeIndex);
}
} catch (NoClassDefFoundError e) {
if (exceptionOnMissingAnnotationClass)
// note: at this point sig is "[unknown]" or VM-style
// name instead of a binary name
throw new TypeNotPresentException(sig, e);
skipAnnotation(buf, false);
return null;
}
catch (TypeNotPresentException e) {
if (exceptionOnMissingAnnotationClass)
throw e;
skipAnnotation(buf, false);
return null;
}
if (selectAnnotationClasses != null && !contains(selectAnnotationClasses, annotationClass)) {
skipAnnotation(buf, false);
return null;
}
AnnotationType type = null;
try {
type = AnnotationType.getInstance(annotationClass);
} catch (IllegalArgumentException e) {
skipAnnotation(buf, false);
return null;
}
Map<String, Class<?>> memberTypes = type.memberTypes();
Map<String, Object> memberValues =
new LinkedHashMap<String, Object>(type.memberDefaults());
int numMembers = buf.getShort() & 0xFFFF;
for (int i = 0; i < numMembers; i++) {
int memberNameIndex = buf.getShort() & 0xFFFF;
String memberName = constPool.getUTF8At(memberNameIndex);
Class<?> memberType = memberTypes.get(memberName);
if (memberType == null) {
// Member is no longer present in annotation type; ignore it
skipMemberValue(buf);
} else {
Object value = parseMemberValue(memberType, buf, constPool, container);
if (value instanceof AnnotationTypeMismatchExceptionProxy)
((AnnotationTypeMismatchExceptionProxy) value).
setMember(type.members().get(memberName));
memberValues.put(memberName, value);
}
}
return annotationForMap(annotationClass, memberValues);
}
/**
* Returns an annotation of the given type backed by the given
* member -> value map.
*/
public static Annotation annotationForMap(final Class<? extends Annotation> type,
final Map<String, Object> memberValues)
{
return AccessController.doPrivileged(new PrivilegedAction<Annotation>() {
public Annotation run() {
return (Annotation) Proxy.newProxyInstance(
type.getClassLoader(), new Class<?>[] { type },
new AnnotationInvocationHandler(type, memberValues));
}});
}
/**
* Parses the annotation member value at the current position in the
* specified byte buffer, resolving constant references in the specified
* constant pool. The cursor of the byte buffer must point to a
* "member_value structure" as described in the
* RuntimeVisibleAnnotations_attribute:
*
* member_value {
* u1 tag;
* union {
* u2 const_value_index;
* {
* u2 type_name_index;
* u2 const_name_index;
* } enum_const_value;
* u2 class_info_index;
* annotation annotation_value;
* {
* u2 num_values;
* member_value values[num_values];
* } array_value;
* } value;
* }
*
* The member must be of the indicated type. If it is not, this
* method returns an AnnotationTypeMismatchExceptionProxy.
*/
@SuppressWarnings("unchecked")
public static Object parseMemberValue(Class<?> memberType,
ByteBuffer buf,
ConstantPool constPool,
Class<?> container) {
Object result = null;
int tag = buf.get();
switch(tag) {
case 'e':
return parseEnumValue((Class<? extends Enum<?>>)memberType, buf, constPool, container);
case 'c':
result = parseClassValue(buf, constPool, container);
break;
case '@':
result = parseAnnotation(buf, constPool, container, true);
break;
case '[':
return parseArray(memberType, buf, constPool, container);
default:
result = parseConst(tag, buf, constPool);
}
if (!(result instanceof ExceptionProxy) &&
!memberType.isInstance(result))
result = new AnnotationTypeMismatchExceptionProxy(
result.getClass() + "[" + result + "]");
return result;
}
/**
* Parses the primitive or String annotation member value indicated by
* the specified tag byte at the current position in the specified byte
* buffer, resolving constant reference in the specified constant pool.
* The cursor of the byte buffer must point to an annotation member value
* of the type indicated by the specified tag, as described in the
* RuntimeVisibleAnnotations_attribute:
*
* u2 const_value_index;
*/
private static Object parseConst(int tag,
ByteBuffer buf, ConstantPool constPool) {
int constIndex = buf.getShort() & 0xFFFF;
switch(tag) {
case 'B':
return Byte.valueOf((byte) constPool.getIntAt(constIndex));
case 'C':
return Character.valueOf((char) constPool.getIntAt(constIndex));
case 'D':
return Double.valueOf(constPool.getDoubleAt(constIndex));
case 'F':
return Float.valueOf(constPool.getFloatAt(constIndex));
case 'I':
return Integer.valueOf(constPool.getIntAt(constIndex));
case 'J':
return Long.valueOf(constPool.getLongAt(constIndex));
case 'S':
return Short.valueOf((short) constPool.getIntAt(constIndex));
case 'Z':
return Boolean.valueOf(constPool.getIntAt(constIndex) != 0);
case 's':
return constPool.getUTF8At(constIndex);
default:
throw new AnnotationFormatError(
"Invalid member-value tag in annotation: " + tag);
}
}
/**
* Parses the Class member value at the current position in the
* specified byte buffer, resolving constant references in the specified
* constant pool. The cursor of the byte buffer must point to a "class
* info index" as described in the RuntimeVisibleAnnotations_attribute:
*
* u2 class_info_index;
*/
private static Object parseClassValue(ByteBuffer buf,
ConstantPool constPool,
Class<?> container) {
int classIndex = buf.getShort() & 0xFFFF;
try {
try {
String sig = constPool.getUTF8At(classIndex);
return parseSig(sig, container);
} catch (IllegalArgumentException ex) {
// support obsolete early jsr175 format class files
return constPool.getClassAt(classIndex);
}
} catch (NoClassDefFoundError e) {
return new TypeNotPresentExceptionProxy("[unknown]", e);
}
catch (TypeNotPresentException e) {
return new TypeNotPresentExceptionProxy(e.typeName(), e.getCause());
}
}
private static Class<?> parseSig(String sig, Class<?> container) {
if (sig.equals("V")) return void.class;
SignatureParser parser = SignatureParser.make();
TypeSignature typeSig = parser.parseTypeSig(sig);
GenericsFactory factory = CoreReflectionFactory.make(container, ClassScope.make(container));
Reifier reify = Reifier.make(factory);
typeSig.accept(reify);
Type result = reify.getResult();
return toClass(result);
}
static Class<?> toClass(Type o) {
if (o instanceof GenericArrayType)
return Array.newInstance(toClass(((GenericArrayType)o).getGenericComponentType()),
0)
.getClass();
return (Class)o;
}
/**
* Parses the enum constant member value at the current position in the
* specified byte buffer, resolving constant references in the specified
* constant pool. The cursor of the byte buffer must point to a
* "enum_const_value structure" as described in the
* RuntimeVisibleAnnotations_attribute:
*
* {
* u2 type_name_index;
* u2 const_name_index;
* } enum_const_value;
*/
@SuppressWarnings({"rawtypes", "unchecked"})
private static Object parseEnumValue(Class<? extends Enum> enumType, ByteBuffer buf,
ConstantPool constPool,
Class<?> container) {
int typeNameIndex = buf.getShort() & 0xFFFF;
String typeName = constPool.getUTF8At(typeNameIndex);
int constNameIndex = buf.getShort() & 0xFFFF;
String constName = constPool.getUTF8At(constNameIndex);
if (!typeName.endsWith(";")) {
// support now-obsolete early jsr175-format class files.
if (!enumType.getName().equals(typeName))
return new AnnotationTypeMismatchExceptionProxy(
typeName + "." + constName);
} else if (enumType != parseSig(typeName, container)) {
return new AnnotationTypeMismatchExceptionProxy(
typeName + "." + constName);
}
try {
return Enum.valueOf(enumType, constName);
} catch(IllegalArgumentException e) {
return new EnumConstantNotPresentExceptionProxy(
(Class<? extends Enum<?>>)enumType, constName);
}
}
/**
* Parses the array value at the current position in the specified byte
* buffer, resolving constant references in the specified constant pool.
* The cursor of the byte buffer must point to an array value struct
* as specified in the RuntimeVisibleAnnotations_attribute:
*
* {
* u2 num_values;
* member_value values[num_values];
* } array_value;
*
* If the array values do not match arrayType, an
* AnnotationTypeMismatchExceptionProxy will be returned.
*/
@SuppressWarnings("unchecked")
private static Object parseArray(Class<?> arrayType,
ByteBuffer buf,
ConstantPool constPool,
Class<?> container) {
int length = buf.getShort() & 0xFFFF; // Number of array components
Class<?> componentType = arrayType.getComponentType();
if (componentType == byte.class) {
return parseByteArray(length, buf, constPool);
} else if (componentType == char.class) {
return parseCharArray(length, buf, constPool);
} else if (componentType == double.class) {
return parseDoubleArray(length, buf, constPool);
} else if (componentType == float.class) {
return parseFloatArray(length, buf, constPool);
} else if (componentType == int.class) {
return parseIntArray(length, buf, constPool);
} else if (componentType == long.class) {
return parseLongArray(length, buf, constPool);
} else if (componentType == short.class) {
return parseShortArray(length, buf, constPool);
} else if (componentType == boolean.class) {
return parseBooleanArray(length, buf, constPool);
} else if (componentType == String.class) {
return parseStringArray(length, buf, constPool);
} else if (componentType == Class.class) {
return parseClassArray(length, buf, constPool, container);
} else if (componentType.isEnum()) {
return parseEnumArray(length, (Class<? extends Enum<?>>)componentType, buf,
constPool, container);
} else {
assert componentType.isAnnotation();
return parseAnnotationArray(length, (Class <? extends Annotation>)componentType, buf,
constPool, container);
}
}
private static Object parseByteArray(int length,
ByteBuffer buf, ConstantPool constPool) {
byte[] result = new byte[length];
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'B') {
int index = buf.getShort() & 0xFFFF;
result[i] = (byte) constPool.getIntAt(index);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseCharArray(int length,
ByteBuffer buf, ConstantPool constPool) {
char[] result = new char[length];
boolean typeMismatch = false;
byte tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'C') {
int index = buf.getShort() & 0xFFFF;
result[i] = (char) constPool.getIntAt(index);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseDoubleArray(int length,
ByteBuffer buf, ConstantPool constPool) {
double[] result = new double[length];
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'D') {
int index = buf.getShort() & 0xFFFF;
result[i] = constPool.getDoubleAt(index);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseFloatArray(int length,
ByteBuffer buf, ConstantPool constPool) {
float[] result = new float[length];
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'F') {
int index = buf.getShort() & 0xFFFF;
result[i] = constPool.getFloatAt(index);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseIntArray(int length,
ByteBuffer buf, ConstantPool constPool) {
int[] result = new int[length];
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'I') {
int index = buf.getShort() & 0xFFFF;
result[i] = constPool.getIntAt(index);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseLongArray(int length,
ByteBuffer buf, ConstantPool constPool) {
long[] result = new long[length];
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'J') {
int index = buf.getShort() & 0xFFFF;
result[i] = constPool.getLongAt(index);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseShortArray(int length,
ByteBuffer buf, ConstantPool constPool) {
short[] result = new short[length];
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'S') {
int index = buf.getShort() & 0xFFFF;
result[i] = (short) constPool.getIntAt(index);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseBooleanArray(int length,
ByteBuffer buf, ConstantPool constPool) {
boolean[] result = new boolean[length];
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'Z') {
int index = buf.getShort() & 0xFFFF;
result[i] = (constPool.getIntAt(index) != 0);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseStringArray(int length,
ByteBuffer buf, ConstantPool constPool) {
String[] result = new String[length];
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 's') {
int index = buf.getShort() & 0xFFFF;
result[i] = constPool.getUTF8At(index);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseClassArray(int length,
ByteBuffer buf,
ConstantPool constPool,
Class<?> container) {
Object[] result = new Class<?>[length];
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'c') {
result[i] = parseClassValue(buf, constPool, container);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseEnumArray(int length, Class<? extends Enum<?>> enumType,
ByteBuffer buf,
ConstantPool constPool,
Class<?> container) {
Object[] result = (Object[]) Array.newInstance(enumType, length);
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == 'e') {
result[i] = parseEnumValue(enumType, buf, constPool, container);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
private static Object parseAnnotationArray(int length,
Class<? extends Annotation> annotationType,
ByteBuffer buf,
ConstantPool constPool,
Class<?> container) {
Object[] result = (Object[]) Array.newInstance(annotationType, length);
boolean typeMismatch = false;
int tag = 0;
for (int i = 0; i < length; i++) {
tag = buf.get();
if (tag == '@') {
result[i] = parseAnnotation(buf, constPool, container, true);
} else {
skipMemberValue(tag, buf);
typeMismatch = true;
}
}
return typeMismatch ? exceptionProxy(tag) : result;
}
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