RuntimeVisibleAnnotations_attribute and
* RuntimeInvisibleAnnotations_attribute.
*
* To obtain an AnnotationAttribute object, invoke
* getAttribute(AnnotationsAttribute.visibleTag)
* in ClassFile, MethodInfo,
* or FieldInfo. The obtained attribute is a
* runtime visible annotations attribute.
* If the parameter is
* AnnotationAttribute.invisibleTag, then the obtained
* attribute is a runtime invisible one.
*
*
For example, * *
* 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 + ")");
*
*
* This code snippet retrieves an annotation of the type Author
* from the MethodInfo object specified by minfo.
* Then, it prints the value of name in Author.
*
*
If the annotation type Author is annotated by a meta annotation:
*
*
* @Retention(RetentionPolicy.RUNTIME) ** *
Then Author is visible at runtime. Therefore, the third
* statement of the code snippet above must be changed into:
*
*
* AnnotationsAttribute attr = (AnnotationsAttribute) * minfo.getAttribute(AnnotationsAttribute.visibleTag); ** *
The attribute tag must be visibleTag instead of
* invisibleTag.
*
*
If the member value of an annotation is not specified, the default value
* is used as that member value. If so, getMemberValue() in
* Annotation returns null
* since the default value is not included in the
* AnnotationsAttribute. It is included in the
* AnnotationDefaultAttribute of the method declared in the
* annotation type.
*
*
If you want to record a new AnnotationAttribute object, execute the * following snippet: * *
* 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();
*
*
* The last statement is necessary if the class file was produced by
* Javassist or JDK 1.4. Otherwise, it is not necessary.
*
* @see AnnotationDefaultAttribute
* @see javassist.bytecode.annotation.Annotation
*/
public class AnnotationsAttribute extends AttributeInfo {
/**
* The name of the RuntimeVisibleAnnotations attribute.
*/
public static final String visibleTag = "RuntimeVisibleAnnotations";
/**
* The name of the RuntimeInvisibleAnnotations attribute.
*/
public static final String invisibleTag = "RuntimeInvisibleAnnotations";
/**
* Constructs a Runtime(In)VisibleAnnotations_attribute.
*
* @param cp constant pool
* @param attrname attribute name (visibleTag or
* invisibleTag).
* @param info the contents of this attribute. It does not
* include attribute_name_index or
* attribute_length.
*/
public AnnotationsAttribute(ConstPool cp, String attrname, byte[] info) {
super(cp, attrname, info);
}
/**
* Constructs an empty
* Runtime(In)VisibleAnnotations_attribute.
* A new annotation can be later added to the created attribute
* by setAnnotations().
*
* @param cp constant pool
* @param attrname attribute name (visibleTag or
* invisibleTag).
* @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 num_annotations.
*/
public int numAnnotations() {
return ByteArray.readU16bit(info, 0);
}
/**
* Copies this attribute and returns a new copy.
*/
public AttributeInfo copy(ConstPool newCp, Map 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
* getAnnotations() 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);
}
/**
* 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
* setAnnotations().
*
* @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 Annotation 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:
*
setAnnotations(new Annotation[] { annotation })
*
* @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.
*/
void renameClass(String oldname, String newname) {
HashMap map = new HashMap();
map.put(oldname, newname);
renameClass(map);
}
void renameClass(Map classnames) {
Renamer renamer = new Renamer(info, getConstPool(), classnames);
try {
renamer.annotationArray();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
void getRefClasses(Map classnames) { renameClass(classnames); }
/**
* Returns a string representation of this object.
*/
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;
}
final int memberValuePair(int pos) throws Exception {
int nameIndex = ByteArray.readU16bit(info, pos);
return memberValuePair(pos + 2, nameIndex);
}
int memberValuePair(int pos, int nameIndex) throws Exception {
return memberValue(pos);
}
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;
}
}
void constValueMember(int tag, int index) throws Exception {}
void enumMemberValue(int pos, int typeNameIndex, int constNameIndex)
throws Exception {
}
void classMemberValue(int pos, int index) throws Exception {}
int annotationMemberValue(int pos) throws Exception {
return annotation(pos);
}
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 classnames;
/**
* Constructs a renamer. It renames some class names
* into the new names specified by map.
*
* @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 map) {
super(info);
cpool = cp;
classnames = map;
}
int annotation(int pos, int type, int numPairs) throws Exception {
renameType(pos - 4, type);
return super.annotation(pos, type, numPairs);
}
void enumMemberValue(int pos, int typeNameIndex, int constNameIndex)
throws Exception
{
renameType(pos + 1, typeNameIndex);
super.enumMemberValue(pos, typeNameIndex, constNameIndex);
}
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 classnames;
/**
* Constructs a copier. This copier renames some class names
* into the new names specified by map 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 map) {
super(info);
output = new ByteArrayOutputStream();
writer = new AnnotationsWriter(output, dest);
srcPool = src;
destPool = dest;
classnames = map;
}
byte[] close() throws IOException {
writer.close();
return output.toByteArray();
}
void parameters(int numParam, int pos) throws Exception {
writer.numParameters(numParam);
super.parameters(numParam, pos);
}
int annotationArray(int pos, int num) throws Exception {
writer.numAnnotations(num);
return super.annotationArray(pos, num);
}
int annotation(int pos, int type, int numPairs) throws Exception {
writer.annotation(copyType(type), numPairs);
return super.annotation(pos, type, numPairs);
}
int memberValuePair(int pos, int nameIndex) throws Exception {
writer.memberValuePair(copy(nameIndex));
return super.memberValuePair(pos, nameIndex);
}
void constValueMember(int tag, int index) throws Exception {
writer.constValueIndex(tag, copy(index));
super.constValueMember(tag, index);
}
void enumMemberValue(int pos, int typeNameIndex, int constNameIndex)
throws Exception
{
writer.enumConstValue(copyType(typeNameIndex), copy(constNameIndex));
super.enumMemberValue(pos, typeNameIndex, constNameIndex);
}
void classMemberValue(int pos, int index) throws Exception {
writer.classInfoIndex(copyType(index));
super.classMemberValue(pos, index);
}
int annotationMemberValue(int pos) throws Exception {
writer.annotationValue();
return super.annotationMemberValue(pos);
}
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