AnnotationsAttribute.java
/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. Alternatively, the contents of this file may be used under
* the terms of the GNU Lesser General Public License Version 2.1 or later,
* or the Apache License Version 2.0.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*/
package javassist.bytecode;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javassist.bytecode.annotation.Annotation;
import javassist.bytecode.annotation.AnnotationMemberValue;
import javassist.bytecode.annotation.AnnotationsWriter;
import javassist.bytecode.annotation.ArrayMemberValue;
import javassist.bytecode.annotation.BooleanMemberValue;
import javassist.bytecode.annotation.ByteMemberValue;
import javassist.bytecode.annotation.CharMemberValue;
import javassist.bytecode.annotation.ClassMemberValue;
import javassist.bytecode.annotation.DoubleMemberValue;
import javassist.bytecode.annotation.EnumMemberValue;
import javassist.bytecode.annotation.FloatMemberValue;
import javassist.bytecode.annotation.IntegerMemberValue;
import javassist.bytecode.annotation.LongMemberValue;
import javassist.bytecode.annotation.MemberValue;
import javassist.bytecode.annotation.ShortMemberValue;
import javassist.bytecode.annotation.StringMemberValue;
/**
* A class representing
* <code>RuntimeVisibleAnnotations_attribute</code> and
* <code>RuntimeInvisibleAnnotations_attribute</code>.
*
* <p>To obtain an AnnotationAttribute object, invoke
* <code>getAttribute(AnnotationsAttribute.visibleTag)</code>
* in <code>ClassFile</code>, <code>MethodInfo</code>,
* or <code>FieldInfo</code>. The obtained attribute is a
* runtime visible annotations attribute.
* If the parameter is
* <code>AnnotationAttribute.invisibleTag</code>, then the obtained
* attribute is a runtime invisible one.
*
* <p>For example,
*
* <pre>
* import javassist.bytecode.annotation.Annotation;
* :
* CtMethod m = ... ;
* MethodInfo minfo = m.getMethodInfo();
* AnnotationsAttribute attr = (AnnotationsAttribute)
* minfo.getAttribute(AnnotationsAttribute.invisibleTag);
* Annotation an = attr.getAnnotation("Author");
* String s = ((StringMemberValue)an.getMemberValue("name")).getValue();
* System.out.println("@Author(name=" + s + ")");
* </pre>
*
* <p>This code snippet retrieves an annotation of the type <code>Author</code>
* from the <code>MethodInfo</code> object specified by <code>minfo</code>.
* Then, it prints the value of <code>name</code> in <code>Author</code>.
*
* <p>If the annotation type <code>Author</code> is annotated by a meta annotation:
*
* <pre>
* @Retention(RetentionPolicy.RUNTIME)
* </pre>
*
* <p>Then <code>Author</code> is visible at runtime. Therefore, the third
* statement of the code snippet above must be changed into:
*
* <pre>
* AnnotationsAttribute attr = (AnnotationsAttribute)
* minfo.getAttribute(AnnotationsAttribute.visibleTag);
* </pre>
*
* <p>The attribute tag must be <code>visibleTag</code> instead of
* <code>invisibleTag</code>.
*
* <p>If the member value of an annotation is not specified, the default value
* is used as that member value. If so, <code>getMemberValue()</code> in
* <code>Annotation</code> returns <code>null</code>
* since the default value is not included in the
* <code>AnnotationsAttribute</code>. It is included in the
* <code>AnnotationDefaultAttribute</code> of the method declared in the
* annotation type.
*
* <p>If you want to record a new AnnotationAttribute object, execute the
* following snippet:
*
* <pre>
* ClassFile cf = ... ;
* ConstPool cp = cf.getConstPool();
* AnnotationsAttribute attr
* = new AnnotationsAttribute(cp, AnnotationsAttribute.visibleTag);
* Annotation a = new Annotation("Author", cp);
* a.addMemberValue("name", new StringMemberValue("Chiba", cp));
* attr.setAnnotation(a);
* cf.addAttribute(attr);
* cf.setVersionToJava5();
* </pre>
*
* <p>The last statement is necessary if the class file was produced by
* <code>javac</code> of JDK 1.4 or earlier. Otherwise, it is not necessary.
*
* @see AnnotationDefaultAttribute
* @see javassist.bytecode.annotation.Annotation
*/
public class AnnotationsAttribute extends AttributeInfo {
/**
* The name of the <code>RuntimeVisibleAnnotations</code> attribute.
*/
public static final String visibleTag = "RuntimeVisibleAnnotations";
/**
* The name of the <code>RuntimeInvisibleAnnotations</code> attribute.
*/
public static final String invisibleTag = "RuntimeInvisibleAnnotations";
/**
* Constructs a <code>Runtime(In)VisibleAnnotations_attribute</code>.
*
* @param cp constant pool
* @param attrname attribute name (<code>visibleTag</code> or
* <code>invisibleTag</code>).
* @param info the contents of this attribute. It does not
* include <code>attribute_name_index</code> or
* <code>attribute_length</code>.
*/
public AnnotationsAttribute(ConstPool cp, String attrname, byte[] info) {
super(cp, attrname, info);
}
/**
* Constructs an empty
* <code>Runtime(In)VisibleAnnotations_attribute</code>.
* A new annotation can be later added to the created attribute
* by <code>setAnnotations()</code>.
*
* @param cp constant pool
* @param attrname attribute name (<code>visibleTag</code> or
* <code>invisibleTag</code>).
* @see #setAnnotations(Annotation[])
*/
public AnnotationsAttribute(ConstPool cp, String attrname) {
this(cp, attrname, new byte[] { 0, 0 });
}
/**
* @param n the attribute name.
*/
AnnotationsAttribute(ConstPool cp, int n, DataInputStream in)
throws IOException
{
super(cp, n, in);
}
/**
* Returns <code>num_annotations</code>.
*/
public int numAnnotations() {
return ByteArray.readU16bit(info, 0);
}
/**
* Copies this attribute and returns a new copy.
*/
@Override
public AttributeInfo copy(ConstPool newCp, Map<String,String> classnames) {
Copier copier = new Copier(info, constPool, newCp, classnames);
try {
copier.annotationArray();
return new AnnotationsAttribute(newCp, getName(), copier.close());
}
catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* Parses the annotations and returns a data structure representing
* the annotation with the specified type. See also
* <code>getAnnotations()</code> as to the returned data structure.
*
* @param type the annotation type.
* @return null if the specified annotation type is not included.
* @see #getAnnotations()
*/
public Annotation getAnnotation(String type) {
Annotation[] annotations = getAnnotations();
for (int i = 0; i < annotations.length; i++) {
if (annotations[i].getTypeName().equals(type))
return annotations[i];
}
return null;
}
/**
* Adds an annotation. If there is an annotation with the same type,
* it is removed before the new annotation is added.
*
* @param annotation the added annotation.
*/
public void addAnnotation(Annotation annotation) {
String type = annotation.getTypeName();
Annotation[] annotations = getAnnotations();
for (int i = 0; i < annotations.length; i++) {
if (annotations[i].getTypeName().equals(type)) {
annotations[i] = annotation;
setAnnotations(annotations);
return;
}
}
Annotation[] newlist = new Annotation[annotations.length + 1];
System.arraycopy(annotations, 0, newlist, 0, annotations.length);
newlist[annotations.length] = annotation;
setAnnotations(newlist);
}
/**
* Removes an annotation by type.
* After removing an annotation, if {@link #numAnnotations()} returns 0,
* this annotations attribute has to be removed.
*
* @param type of annotation to remove
* @return whether an annotation with the given type has been removed
* @since 3.21
*/
public boolean removeAnnotation(String type) {
Annotation[] annotations = getAnnotations();
for (int i = 0; i < annotations.length; i++) {
if (annotations[i].getTypeName().equals(type)) {
Annotation[] newlist = new Annotation[annotations.length - 1];
System.arraycopy(annotations, 0, newlist, 0, i);
if (i < annotations.length - 1) {
System.arraycopy(annotations, i + 1, newlist, i,
annotations.length - i - 1);
}
setAnnotations(newlist);
return true;
}
}
return false;
}
/**
* Parses the annotations and returns a data structure representing
* that parsed annotations. Note that changes of the node values of the
* returned tree are not reflected on the annotations represented by
* this object unless the tree is copied back to this object by
* <code>setAnnotations()</code>.
*
* @see #setAnnotations(Annotation[])
*/
public Annotation[] getAnnotations() {
try {
return new Parser(info, constPool).parseAnnotations();
}
catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* Changes the annotations represented by this object according to
* the given array of <code>Annotation</code> objects.
*
* @param annotations the data structure representing the
* new annotations.
*/
public void setAnnotations(Annotation[] annotations) {
ByteArrayOutputStream output = new ByteArrayOutputStream();
AnnotationsWriter writer = new AnnotationsWriter(output, constPool);
try {
int n = annotations.length;
writer.numAnnotations(n);
for (int i = 0; i < n; ++i)
annotations[i].write(writer);
writer.close();
}
catch (IOException e) {
throw new RuntimeException(e); // should never reach here.
}
set(output.toByteArray());
}
/**
* Changes the annotations. A call to this method is equivalent to:
* <pre>setAnnotations(new Annotation[] { annotation })</pre>
*
* @param annotation the data structure representing
* the new annotation.
*/
public void setAnnotation(Annotation annotation) {
setAnnotations(new Annotation[] { annotation });
}
/**
* @param oldname a JVM class name.
* @param newname a JVM class name.
*/
@Override
void renameClass(String oldname, String newname) {
Map<String,String> map = new HashMap<String,String>();
map.put(oldname, newname);
renameClass(map);
}
@Override
void renameClass(Map<String,String> classnames) {
Renamer renamer = new Renamer(info, getConstPool(), classnames);
try {
renamer.annotationArray();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
@Override
void getRefClasses(Map<String,String> classnames) { renameClass(classnames); }
/**
* Returns a string representation of this object.
*/
@Override
public String toString() {
Annotation[] a = getAnnotations();
StringBuilder sbuf = new StringBuilder();
int i = 0;
while (i < a.length) {
sbuf.append(a[i++].toString());
if (i != a.length)
sbuf.append(", ");
}
return sbuf.toString();
}
static class Walker {
byte[] info;
Walker(byte[] attrInfo) {
info = attrInfo;
}
final void parameters() throws Exception {
int numParam = info[0] & 0xff;
parameters(numParam, 1);
}
void parameters(int numParam, int pos) throws Exception {
for (int i = 0; i < numParam; ++i)
pos = annotationArray(pos);
}
final void annotationArray() throws Exception {
annotationArray(0);
}
final int annotationArray(int pos) throws Exception {
int num = ByteArray.readU16bit(info, pos);
return annotationArray(pos + 2, num);
}
int annotationArray(int pos, int num) throws Exception {
for (int i = 0; i < num; ++i)
pos = annotation(pos);
return pos;
}
final int annotation(int pos) throws Exception {
int type = ByteArray.readU16bit(info, pos);
int numPairs = ByteArray.readU16bit(info, pos + 2);
return annotation(pos + 4, type, numPairs);
}
int annotation(int pos, int type, int numPairs) throws Exception {
for (int j = 0; j < numPairs; ++j)
pos = memberValuePair(pos);
return pos;
}
/**
* {@code element_value_paris}
*/
final int memberValuePair(int pos) throws Exception {
int nameIndex = ByteArray.readU16bit(info, pos);
return memberValuePair(pos + 2, nameIndex);
}
/**
* {@code element_value_paris[]}
*/
int memberValuePair(int pos, int nameIndex) throws Exception {
return memberValue(pos);
}
/**
* {@code element_value}
*/
final int memberValue(int pos) throws Exception {
int tag = info[pos] & 0xff;
if (tag == 'e') {
int typeNameIndex = ByteArray.readU16bit(info, pos + 1);
int constNameIndex = ByteArray.readU16bit(info, pos + 3);
enumMemberValue(pos, typeNameIndex, constNameIndex);
return pos + 5;
}
else if (tag == 'c') {
int index = ByteArray.readU16bit(info, pos + 1);
classMemberValue(pos, index);
return pos + 3;
}
else if (tag == '@')
return annotationMemberValue(pos + 1);
else if (tag == '[') {
int num = ByteArray.readU16bit(info, pos + 1);
return arrayMemberValue(pos + 3, num);
}
else { // primitive types or String.
int index = ByteArray.readU16bit(info, pos + 1);
constValueMember(tag, index);
return pos + 3;
}
}
/**
* {@code const_value_index}
*/
void constValueMember(int tag, int index) throws Exception {}
/**
* {@code enum_const_value}
*/
void enumMemberValue(int pos, int typeNameIndex, int constNameIndex)
throws Exception {
}
/**
* {@code class_info_index}
*/
void classMemberValue(int pos, int index) throws Exception {}
/**
* {@code annotation_value}
*/
int annotationMemberValue(int pos) throws Exception {
return annotation(pos);
}
/**
* {@code array_value}
*/
int arrayMemberValue(int pos, int num) throws Exception {
for (int i = 0; i < num; ++i) {
pos = memberValue(pos);
}
return pos;
}
}
static class Renamer extends Walker {
ConstPool cpool;
Map<String,String> classnames;
/**
* Constructs a renamer. It renames some class names
* into the new names specified by <code>map</code>.
*
* @param info the annotations attribute.
* @param cp the constant pool.
* @param map pairs of replaced and substituted class names.
* It can be null.
*/
Renamer(byte[] info, ConstPool cp, Map<String,String> map) {
super(info);
cpool = cp;
classnames = map;
}
@Override
int annotation(int pos, int type, int numPairs) throws Exception {
renameType(pos - 4, type);
return super.annotation(pos, type, numPairs);
}
@Override
void enumMemberValue(int pos, int typeNameIndex, int constNameIndex)
throws Exception
{
renameType(pos + 1, typeNameIndex);
super.enumMemberValue(pos, typeNameIndex, constNameIndex);
}
@Override
void classMemberValue(int pos, int index) throws Exception {
renameType(pos + 1, index);
super.classMemberValue(pos, index);
}
private void renameType(int pos, int index) {
String name = cpool.getUtf8Info(index);
String newName = Descriptor.rename(name, classnames);
if (!name.equals(newName)) {
int index2 = cpool.addUtf8Info(newName);
ByteArray.write16bit(index2, info, pos);
}
}
}
static class Copier extends Walker {
ByteArrayOutputStream output;
AnnotationsWriter writer;
ConstPool srcPool, destPool;
Map<String,String> classnames;
/**
* Constructs a copier. This copier renames some class names
* into the new names specified by <code>map</code> when it copies
* an annotation attribute.
*
* @param info the source attribute.
* @param src the constant pool of the source class.
* @param dest the constant pool of the destination class.
* @param map pairs of replaced and substituted class names.
* It can be null.
*/
Copier(byte[] info, ConstPool src, ConstPool dest, Map<String,String> map) {
this(info, src, dest, map, true);
}
Copier(byte[] info, ConstPool src, ConstPool dest, Map<String,String> map, boolean makeWriter) {
super(info);
output = new ByteArrayOutputStream();
if (makeWriter)
writer = new AnnotationsWriter(output, dest);
srcPool = src;
destPool = dest;
classnames = map;
}
byte[] close() throws IOException {
writer.close();
return output.toByteArray();
}
@Override
void parameters(int numParam, int pos) throws Exception {
writer.numParameters(numParam);
super.parameters(numParam, pos);
}
@Override
int annotationArray(int pos, int num) throws Exception {
writer.numAnnotations(num);
return super.annotationArray(pos, num);
}
@Override
int annotation(int pos, int type, int numPairs) throws Exception {
writer.annotation(copyType(type), numPairs);
return super.annotation(pos, type, numPairs);
}
@Override
int memberValuePair(int pos, int nameIndex) throws Exception {
writer.memberValuePair(copy(nameIndex));
return super.memberValuePair(pos, nameIndex);
}
@Override
void constValueMember(int tag, int index) throws Exception {
writer.constValueIndex(tag, copy(index));
super.constValueMember(tag, index);
}
@Override
void enumMemberValue(int pos, int typeNameIndex, int constNameIndex)
throws Exception
{
writer.enumConstValue(copyType(typeNameIndex), copy(constNameIndex));
super.enumMemberValue(pos, typeNameIndex, constNameIndex);
}
@Override
void classMemberValue(int pos, int index) throws Exception {
writer.classInfoIndex(copyType(index));
super.classMemberValue(pos, index);
}
@Override
int annotationMemberValue(int pos) throws Exception {
writer.annotationValue();
return super.annotationMemberValue(pos);
}
@Override
int arrayMemberValue(int pos, int num) throws Exception {
writer.arrayValue(num);
return super.arrayMemberValue(pos, num);
}
/**
* Copies a constant pool entry into the destination constant pool
* and returns the index of the copied entry.
*
* @param srcIndex the index of the copied entry into the source
* constant pool.
* @return the index of the copied item into the destination
* constant pool.
*/
int copy(int srcIndex) {
return srcPool.copy(srcIndex, destPool, classnames);
}
/**
* Copies a constant pool entry into the destination constant pool
* and returns the index of the copied entry. That entry must be
* a Utf8Info representing a class name in the L<class name>; form.
*
* @param srcIndex the index of the copied entry into the source
* constant pool.
* @return the index of the copied item into the destination
* constant pool.
*/
int copyType(int srcIndex) {
String name = srcPool.getUtf8Info(srcIndex);
String newName = Descriptor.rename(name, classnames);
return destPool.addUtf8Info(newName);
}
}
static class Parser extends Walker {
ConstPool pool;
Annotation[][] allParams; // all parameters
Annotation[] allAnno; // all annotations
Annotation currentAnno; // current annotation
MemberValue currentMember; // current member
/**
* Constructs a parser. This parser constructs a parse tree of
* the annotations.
*
* @param info the attribute.
* @param src the constant pool.
*/
Parser(byte[] info, ConstPool cp) {
super(info);
pool = cp;
}
Annotation[][] parseParameters() throws Exception {
parameters();
return allParams;
}
Annotation[] parseAnnotations() throws Exception {
annotationArray();
return allAnno;
}
MemberValue parseMemberValue() throws Exception {
memberValue(0);
return currentMember;
}
@Override
void parameters(int numParam, int pos) throws Exception {
Annotation[][] params = new Annotation[numParam][];
for (int i = 0; i < numParam; ++i) {
pos = annotationArray(pos);
params[i] = allAnno;
}
allParams = params;
}
@Override
int annotationArray(int pos, int num) throws Exception {
Annotation[] array = new Annotation[num];
for (int i = 0; i < num; ++i) {
pos = annotation(pos);
array[i] = currentAnno;
}
allAnno = array;
return pos;
}
@Override
int annotation(int pos, int type, int numPairs) throws Exception {
currentAnno = new Annotation(type, pool);
return super.annotation(pos, type, numPairs);
}
@Override
int memberValuePair(int pos, int nameIndex) throws Exception {
pos = super.memberValuePair(pos, nameIndex);
currentAnno.addMemberValue(nameIndex, currentMember);
return pos;
}
@Override
void constValueMember(int tag, int index) throws Exception {
MemberValue m;
ConstPool cp = pool;
switch (tag) {
case 'B' :
m = new ByteMemberValue(index, cp);
break;
case 'C' :
m = new CharMemberValue(index, cp);
break;
case 'D' :
m = new DoubleMemberValue(index, cp);
break;
case 'F' :
m = new FloatMemberValue(index, cp);
break;
case 'I' :
m = new IntegerMemberValue(index, cp);
break;
case 'J' :
m = new LongMemberValue(index, cp);
break;
case 'S' :
m = new ShortMemberValue(index, cp);
break;
case 'Z' :
m = new BooleanMemberValue(index, cp);
break;
case 's' :
m = new StringMemberValue(index, cp);
break;
default :
throw new RuntimeException("unknown tag:" + tag);
}
currentMember = m;
super.constValueMember(tag, index);
}
@Override
void enumMemberValue(int pos, int typeNameIndex, int constNameIndex)
throws Exception
{
currentMember = new EnumMemberValue(typeNameIndex,
constNameIndex, pool);
super.enumMemberValue(pos, typeNameIndex, constNameIndex);
}
@Override
void classMemberValue(int pos, int index) throws Exception {
currentMember = new ClassMemberValue(index, pool);
super.classMemberValue(pos, index);
}
@Override
int annotationMemberValue(int pos) throws Exception {
Annotation anno = currentAnno;
pos = super.annotationMemberValue(pos);
currentMember = new AnnotationMemberValue(currentAnno, pool);
currentAnno = anno;
return pos;
}
@Override
int arrayMemberValue(int pos, int num) throws Exception {
ArrayMemberValue amv = new ArrayMemberValue(pool);
MemberValue[] elements = new MemberValue[num];
for (int i = 0; i < num; ++i) {
pos = memberValue(pos);
elements[i] = currentMember;
}
amv.setValue(elements);
currentMember = amv;
return pos;
}
}
}