http://asm.ow2.org/: Tree API of ASM, a very small and fast Java bytecode manipulation framework (OW2)
  • Eric Bruneton
  • Eugene Kuleshov
  • Remi Forax 
// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
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//    notice, this list of conditions and the following disclaimer in the
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//    this software without specific prior written permission.
//
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package org.objectweb.asm.tree;

import java.util.ArrayList;
import java.util.List;
import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Opcodes;


A node that represents an annotation.

Author:Eric Bruneton
/**
 * A node that represents an annotation.
 *
 * @author Eric Bruneton
 */
public class AnnotationNode extends AnnotationVisitor {

  
The class descriptor of the annotation class. 
/** The class descriptor of the annotation class. */
  public String desc;

  
The name value pairs of this annotation. Each name value pair is stored as two consecutive elements in the list. The name is a String, and the value may be a Byte, Boolean, Character, Short, Integer, Long, Float, Double, String or Type, or a two elements String array (for enumeration values), an AnnotationNode, or a List of values of one of the preceding types. The list may be null if there is no name value pair.

/**
   * The name value pairs of this annotation. Each name value pair is stored as two consecutive
   * elements in the list. The name is a {@link String}, and the value may be a {@link Byte}, {@link
   * Boolean}, {@link Character}, {@link Short}, {@link Integer}, {@link Long}, {@link Float},
   * {@link Double}, {@link String} or {@link org.objectweb.asm.Type}, or a two elements String
   * array (for enumeration values), an {@link AnnotationNode}, or a {@link List} of values of one
   * of the preceding types. The list may be <tt>null</tt> if there is no name value pair.
   */
  public List<Object> values;

  
Constructs a new AnnotationNode. Subclasses must not use this constructor. Instead, they must use the AnnotationNode(int, String) version. 
Params:
  • descriptor – the class descriptor of the annotation class.
Throws:
/**
   * Constructs a new {@link AnnotationNode}. <i>Subclasses must not use this constructor</i>.
   * Instead, they must use the {@link #AnnotationNode(int, String)} version.
   *
   * @param descriptor the class descriptor of the annotation class.
   * @throws IllegalStateException If a subclass calls this constructor.
   */
  public AnnotationNode(final String descriptor) {
    this(Opcodes.ASM6, descriptor);
    if (getClass() != AnnotationNode.class) {
      throw new IllegalStateException();
    }
  }

  
Constructs a new AnnotationNode. 
Params:
/**
   * Constructs a new {@link AnnotationNode}.
   *
   * @param api the ASM API version implemented by this visitor. Must be one of {@link
   *     Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link
   *     Opcodes#ASM7_EXPERIMENTAL}.
   * @param descriptor the class descriptor of the annotation class.
   */
  public AnnotationNode(final int api, final String descriptor) {
    super(api);
    this.desc = descriptor;
  }

  
Constructs a new AnnotationNode to visit an array value. 
Params:
  • values – where the visited values must be stored.
/**
   * Constructs a new {@link AnnotationNode} to visit an array value.
   *
   * @param values where the visited values must be stored.
   */
  AnnotationNode(final List<Object> values) {
    super(Opcodes.ASM6);
    this.values = values;
  }

  // ------------------------------------------------------------------------
  // Implementation of the AnnotationVisitor abstract class
  // ------------------------------------------------------------------------

  @Override
  public void visit(final String name, final Object value) {
    if (values == null) {
      values = new ArrayList<Object>(this.desc != null ? 2 : 1);
    }
    if (this.desc != null) {
      values.add(name);
    }
    if (value instanceof byte[]) {
      values.add(Util.asArrayList((byte[]) value));
    } else if (value instanceof boolean[]) {
      values.add(Util.asArrayList((boolean[]) value));
    } else if (value instanceof short[]) {
      values.add(Util.asArrayList((short[]) value));
    } else if (value instanceof char[]) {
      values.add(Util.asArrayList((char[]) value));
    } else if (value instanceof int[]) {
      values.add(Util.asArrayList((int[]) value));
    } else if (value instanceof long[]) {
      values.add(Util.asArrayList((long[]) value));
    } else if (value instanceof float[]) {
      values.add(Util.asArrayList((float[]) value));
    } else if (value instanceof double[]) {
      values.add(Util.asArrayList((double[]) value));
    } else {
      values.add(value);
    }
  }

  @Override
  public void visitEnum(final String name, final String descriptor, final String value) {
    if (values == null) {
      values = new ArrayList<Object>(this.desc != null ? 2 : 1);
    }
    if (this.desc != null) {
      values.add(name);
    }
    values.add(new String[] {descriptor, value});
  }

  @Override
  public AnnotationVisitor visitAnnotation(final String name, final String descriptor) {
    if (values == null) {
      values = new ArrayList<Object>(this.desc != null ? 2 : 1);
    }
    if (this.desc != null) {
      values.add(name);
    }
    AnnotationNode annotation = new AnnotationNode(descriptor);
    values.add(annotation);
    return annotation;
  }

  @Override
  public AnnotationVisitor visitArray(final String name) {
    if (values == null) {
      values = new ArrayList<Object>(this.desc != null ? 2 : 1);
    }
    if (this.desc != null) {
      values.add(name);
    }
    List<Object> array = new ArrayList<Object>();
    values.add(array);
    return new AnnotationNode(array);
  }

  @Override
  public void visitEnd() {
    // Nothing to do.
  }

  // ------------------------------------------------------------------------
  // Accept methods
  // ------------------------------------------------------------------------

  
Checks that this annotation node is compatible with the given ASM API version. This method
checks that this node, and all its children recursively, do not contain elements that were
introduced in more recent versions of the ASM API than the given version.

Params:
/**
   * Checks that this annotation node is compatible with the given ASM API version. This method
   * checks that this node, and all its children recursively, do not contain elements that were
   * introduced in more recent versions of the ASM API than the given version.
   *
   * @param api an ASM API version. Must be one of {@link Opcodes#ASM4}, {@link Opcodes#ASM5},
   *     {@link Opcodes#ASM6} or {@link Opcodes#ASM7_EXPERIMENTAL}.
   */
  public void check(final int api) {
    // nothing to do
  }

  
Makes the given visitor visit this annotation.

Params:
  • annotationVisitor – an annotation visitor. Maybe null.
/**
   * Makes the given visitor visit this annotation.
   *
   * @param annotationVisitor an annotation visitor. Maybe <tt>null</tt>.
   */
  public void accept(final AnnotationVisitor annotationVisitor) {
    if (annotationVisitor != null) {
      if (values != null) {
        for (int i = 0, n = values.size(); i < n; i += 2) {
          String name = (String) values.get(i);
          Object value = values.get(i + 1);
          accept(annotationVisitor, name, value);
        }
      }
      annotationVisitor.visitEnd();
    }
  }

  
Makes the given visitor visit a given annotation value.

Params:
  • annotationVisitor – an annotation visitor. Maybe null.
  • name – the value name.
  • value – the actual value.
/**
   * Makes the given visitor visit a given annotation value.
   *
   * @param annotationVisitor an annotation visitor. Maybe <tt>null</tt>.
   * @param name the value name.
   * @param value the actual value.
   */
  static void accept(
      final AnnotationVisitor annotationVisitor, final String name, final Object value) {
    if (annotationVisitor != null) {
      if (value instanceof String[]) {
        String[] typeValue = (String[]) value;
        annotationVisitor.visitEnum(name, typeValue[0], typeValue[1]);
      } else if (value instanceof AnnotationNode) {
        AnnotationNode annotationValue = (AnnotationNode) value;
        annotationValue.accept(annotationVisitor.visitAnnotation(name, annotationValue.desc));
      } else if (value instanceof List) {
        AnnotationVisitor arrayAnnotationVisitor = annotationVisitor.visitArray(name);
        if (arrayAnnotationVisitor != null) {
          List<?> arrayValue = (List<?>) value;
          for (int i = 0, n = arrayValue.size(); i < n; ++i) {
            accept(arrayAnnotationVisitor, null, arrayValue.get(i));
          }
          arrayAnnotationVisitor.visitEnd();
        }
      } else {
        annotationVisitor.visit(name, value);
      }
    }
  }
}