xapi.bytecode.Annotation Maven / Gradle / Ivy
package xapi.bytecode;
import java.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Set;
public class Annotation {
static class Pair {
int name;
MemberValue value;
}
ConstPool pool;
int typeIndex;
LinkedHashMap members; // this sould be LinkedHashMap
// but it is not supported by JDK 1.3.
/**
* Constructs an annotation including no members. A member can be
* later added to the created annotation by addMemberValue().
*
* @param type the index into the constant pool table.
* the entry at that index must be the
* CONSTANT_Utf8_Info structure
* repreenting the name of the annotation interface type.
* @param cp the constant pool table.
*
* @see #addMemberValue(String, MemberValue)
*/
public Annotation(int type, ConstPool cp) {
pool = cp;
typeIndex = type;
members = null;
}
/**
* Constructs an annotation including no members. A member can be
* later added to the created annotation by addMemberValue().
*
* @param typeName the name of the annotation interface type.
* @param cp the constant pool table.
*
* @see #addMemberValue(String, MemberValue)
*/
public Annotation(String typeName, ConstPool cp) {
this(cp.addUtf8Info(Descriptor.of(typeName)), cp);
}
/**
* Constructs an annotation that can be accessed through the interface
* represented by clazz. The values of the members are
* not specified.
*
* @param cp the constant pool table.
* @param clazz the interface.
* @throws NotFoundException when the clazz is not found
*/
public Annotation(ConstPool cp, CtClass clazz)
throws NotFoundException
{
// todo Enums are not supported right now.
this(cp.addUtf8Info(Descriptor.of(clazz.getName())), cp);
if (!clazz.isInterface())
throw new RuntimeException(
"Only interfaces are allowed for Annotation creation.");
CtMethod methods[] = clazz.getDeclaredMethods();
if (methods.length > 0) {
members = new LinkedHashMap();
}
for (int i = 0; i < methods.length; i++) {
CtClass returnType = methods[i].getReturnType();
addMemberValue(methods[i].getName(),
createMemberValue(cp, returnType));
}
}
/**
* Makes an instance of MemberValue.
*
* @param cp the constant pool table.
* @param type the type of the member.
* @return the member value
* @throws NotFoundException when the type is not found
*/
public static MemberValue createMemberValue(ConstPool cp, CtClass type)
throws NotFoundException
{
if (type == CtClass.booleanType)
return new BooleanMemberValue(cp);
else if (type == CtClass.byteType)
return new ByteMemberValue(cp);
else if (type == CtClass.charType)
return new CharMemberValue(cp);
else if (type == CtClass.shortType)
return new ShortMemberValue(cp);
else if (type == CtClass.intType)
return new IntegerMemberValue(cp);
else if (type == CtClass.longType)
return new LongMemberValue(cp);
else if (type == CtClass.floatType)
return new FloatMemberValue(cp);
else if (type == CtClass.doubleType)
return new DoubleMemberValue(cp);
else if (type.getName().equals("java.lang.Class"))
return new ClassMemberValue(cp);
else if (type.getName().equals("java.lang.String"))
return new StringMemberValue(cp);
else if (type.isArray()) {
CtClass arrayType = type.getComponentType();
MemberValue member = createMemberValue(cp, arrayType);
return new ArrayMemberValue(member, cp);
}
else if (type.isInterface()) {
Annotation info = new Annotation(cp, type);
return new AnnotationMemberValue(info, cp);
}
else {
// treat as enum. I know this is not typed,
// but JBoss has an Annotation Compiler for JDK 1.4
// and I want it to work with that. - Bill Burke
EnumMemberValue emv = new EnumMemberValue(cp);
emv.setType(type.getName());
return emv;
}
}
/**
* Adds a new member.
*
* @param nameIndex the index into the constant pool table.
* The entry at that index must be
* a CONSTANT_Utf8_info structure.
* structure representing the member name.
* @param value the member value.
*/
public void addMemberValue(int nameIndex, MemberValue value) {
Pair p = new Pair();
p.name = nameIndex;
p.value = value;
addMemberValue(p);
}
/**
* Adds a new member.
*
* @param name the member name.
* @param value the member value.
*/
public void addMemberValue(String name, MemberValue value) {
Pair p = new Pair();
p.name = pool.addUtf8Info(name);
p.value = value;
if (members == null)
members = new LinkedHashMap();
members.put(name, p);
}
private void addMemberValue(Pair pair) {
String name = pool.getUtf8Info(pair.name);
if (members == null)
members = new LinkedHashMap();
members.put(name, pair);
}
/**
* Returns a string representation of the annotation.
*/
@Override
public String toString() {
StringBuffer buf = new StringBuffer("@");
buf.append(getTypeName());
if (members != null) {
buf.append("(");
Iterator mit = members.keySet().iterator();
while (mit.hasNext()) {
String name = (String)mit.next();
buf.append(name).append("=").append(getMemberValue(name));
if (mit.hasNext())
buf.append(", ");
}
buf.append(")");
}
return buf.toString();
}
/**
* Obtains the name of the annotation type.
*
* @return the type name
*/
public String getTypeName() {
return Descriptor.toClassName(pool.getUtf8Info(typeIndex));
}
/**
* Obtains all the member names.
*
* @return null if no members are defined.
*/
public Set getMemberNames() {
if (members == null)
return new HashSet();
else
return members.keySet();
}
/**
* Obtains the member value with the given name.
*
* If this annotation does not have a value for the
* specified member,
* this method returns null. It does not return a
* MemberValue with the default value.
* The default value can be obtained from the annotation type.
*
* @param name the member name
* @return null if the member cannot be found or if the value is
* the default value.
*
* @see javassist.bytecode.AnnotationDefaultAttribute
*/
public MemberValue getMemberValue(String name) {
if (members == null)
return null;
else {
Pair p = (Pair)members.get(name);
if (p == null)
return null;
else
return p.value;
}
}
/**
* Constructs an annotation-type object representing this annotation.
* For example, if this annotation represents @Author,
* this method returns an Author object.
*
* @param cl class loader for loading an annotation type.
* @param cp class pool for obtaining class files.
* @return the annotation
* @throws ClassNotFoundException if the class cannot found.
* @throws NoSuchClassError if the class linkage fails.
*/
public Object toAnnotationType(ClassLoader cl, ClassPool cp)
throws ClassNotFoundException, NoSuchClassError
{
return AnnotationImpl.make(cl,
MemberValue.loadClass(cl, getTypeName()),
cp, this);
}
/**
* Writes this annotation.
*
* @param writer the output.
* @throws IOException for an error during the write
*/
public void write(AnnotationsWriter writer) throws IOException {
String typeName = pool.getUtf8Info(typeIndex);
if (members == null) {
writer.annotation(typeName, 0);
return;
}
writer.annotation(typeName, members.size());
Iterator it = members.values().iterator();
while (it.hasNext()) {
Pair pair = (Pair)it.next();
writer.memberValuePair(pair.name);
pair.value.write(writer);
}
}
/**
* Returns true if the given object represents the same annotation
* as this object. The equality test checks the member values.
*/
@Override
public boolean equals(Object obj) {
if (obj == this)
return true;
if (obj == null || obj instanceof Annotation == false)
return false;
Annotation other = (Annotation) obj;
if (getTypeName().equals(other.getTypeName()) == false)
return false;
LinkedHashMap otherMembers = other.members;
if (members == otherMembers)
return true;
else if (members == null)
return otherMembers == null;
else
if (otherMembers == null)
return false;
else
return members.equals(otherMembers);
}
}