http://www.javassist.org/: Javassist (JAVA programming ASSISTant) makes Java bytecode manipulation simple. It is a class library for editing bytecodes in Java. (Shigeru Chiba, www.javassist.org) 
/*
 * 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
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
javac of JDK 1.4 or earlier.  Otherwise, it is not necessary.

See Also:
/**
 * 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>
 * &#64;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 RuntimeVisibleAnnotations attribute.

/**
     * The name of the <code>RuntimeVisibleAnnotations</code> attribute.
     */
    public static final String visibleTag = "RuntimeVisibleAnnotations";

    
The name of the RuntimeInvisibleAnnotations attribute.

/**
     * The name of the <code>RuntimeInvisibleAnnotations</code> attribute.
     */
    public static final String invisibleTag = "RuntimeInvisibleAnnotations";

    
Constructs a Runtime(In)VisibleAnnotations_attribute.

Params:
  • cp –            constant pool
  • attrname –      attribute name (visibleTag or
                     invisibleTag).
  • info –          the contents of this attribute.  It does not
                     include attribute_name_index or
                     attribute_length.
/**
     * 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
Runtime(In)VisibleAnnotations_attribute.
A new annotation can be later added to the created attribute
by setAnnotations().

Params:
  • cp –            constant pool
  • attrname –      attribute name (visibleTag or
                     invisibleTag).
See Also:
/**
     * 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 });
    }

    
Params:
  • n –     the attribute name.
/**
     * @param n     the attribute name.
     */
    AnnotationsAttribute(ConstPool cp, int n, DataInputStream in)
        throws IOException
    {
        super(cp, n, in);
    }

    
Returns num_annotations.

/**
     * Returns <code>num_annotations</code>.
     */
    public int numAnnotations() {
        return ByteArray.readU16bit(info, 0);
    }

    
Copies this attribute and returns a new copy.

/**
     * 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
getAnnotations() as to the returned data structure.

Params:
  • type –      the annotation type.
See Also:
Returns:null if the specified annotation type is not included.
/**
     * 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.

Params:
  • annotation –        the added annotation.
/**
     * 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 numAnnotations() returns 0, this annotations attribute has to be removed. 
Params:
  • type –        of annotation to remove
Returns:whether an annotation with the given type has been removed
Since:3.21
/**
     * 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
setAnnotations().

See Also:
  • setAnnotations(Annotation[])
/**
     * 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 Annotation objects.

Params:
  • annotations –           the data structure representing the
                             new annotations.
/**
     * 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:

setAnnotations(new Annotation[] { annotation })


Params:
  • annotation –    the data structure representing
                     the new annotation.
/**
     * 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 });
    }

    
Params:
  • oldname –       a JVM class name.
  • newname –       a JVM class name.
/**
     * @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.

/**
     * 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;
        }

        
element_value_paris 
/**
         * {@code element_value_paris}
         */
        final int memberValuePair(int pos) throws Exception {
            int nameIndex = ByteArray.readU16bit(info, pos);
            return memberValuePair(pos + 2, nameIndex);
        }

        
element_value_paris[] 
/**
         * {@code element_value_paris[]}
         */
        int memberValuePair(int pos, int nameIndex) throws Exception {
            return memberValue(pos);
        }

        
element_value 
/**
         * {@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;
            }
        }

        
const_value_index 
/**
         * {@code const_value_index}
         */
        void constValueMember(int tag, int index) throws Exception {}

        
enum_const_value 
/**
         * {@code enum_const_value}
         */
        void enumMemberValue(int pos, int typeNameIndex, int constNameIndex)
            throws Exception {
        }

        
class_info_index 
/**
         * {@code class_info_index}
         */
        void classMemberValue(int pos, int index) throws Exception {}

        
annotation_value 
/**
         * {@code annotation_value}
         */
        int annotationMemberValue(int pos) throws Exception {
            return annotation(pos);
        }

        
array_value 
/**
         * {@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 map.

Params:
  • info –      the annotations attribute.
  • cp –        the constant pool.
  • map –       pairs of replaced and substituted class names.
                 It can be null.
/**
         * 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 map when it copies
an annotation attribute.

Params:
  • info –      the source attribute.
  • src –       the constant pool of the source class.
  • dest –      the constant pool of the destination class.
  • map –       pairs of replaced and substituted class names.
                 It can be null.
/**
         * 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.

Params:
  • srcIndex –      the index of the copied entry into the source
                     constant pool.
Returns:the index of the copied item into the destination
        constant pool.
/**
         * 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; form.

Params:
  • srcIndex –  the index of the copied entry into the source
                 constant pool.
Returns:         the index of the copied item into the destination
                 constant pool.
/**
         * 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.

Params:
  • info –      the attribute.
  • src –       the constant pool.
/**
         * 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;
        }
    }
}