Scala example source code file (ClassNode.java)

This example Scala source code file (ClassNode.java) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

annotationnode, arraylist, asm, classnode, classvisitor, fieldnode, innerclassnode, list, methodnode, override, string

The ClassNode.java Scala example source code

/***
 * 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
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package scala.tools.asm.tree;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import scala.tools.asm.AnnotationVisitor;
import scala.tools.asm.Attribute;
import scala.tools.asm.ClassVisitor;
import scala.tools.asm.FieldVisitor;
import scala.tools.asm.MethodVisitor;
import scala.tools.asm.Opcodes;

/**
 * A node that represents a class.
 *
 * @author Eric Bruneton
 */
public class ClassNode extends ClassVisitor {

    /**
     * The class version.
     */
    public int version;

    /**
     * The class's access flags (see {@link scala.tools.asm.Opcodes}). This
     * field also indicates if the class is deprecated.
     */
    public int access;

    /**
     * The internal name of the class (see
     * {@link scala.tools.asm.Type#getInternalName() getInternalName}).
     */
    public String name;

    /**
     * The signature of the class. May be <tt>null</tt>.
     */
    public String signature;

    /**
     * The internal of name of the super class (see
     * {@link scala.tools.asm.Type#getInternalName() getInternalName}). For
     * interfaces, the super class is {@link Object}. May be <tt>null</tt>, but
     * only for the {@link Object} class.
     */
    public String superName;

    /**
     * The internal names of the class's interfaces (see
     * {@link scala.tools.asm.Type#getInternalName() getInternalName}). This
     * list is a list of {@link String} objects.
     */
    public List<String> interfaces;

    /**
     * The name of the source file from which this class was compiled. May be
     * <tt>null</tt>.
     */
    public String sourceFile;

    /**
     * Debug information to compute the correspondence between source and
     * compiled elements of the class. May be <tt>null</tt>.
     */
    public String sourceDebug;

    /**
     * The internal name of the enclosing class of the class. May be
     * <tt>null</tt>.
     */
    public String outerClass;

    /**
     * The name of the method that contains the class, or <tt>null</tt> if the
     * class is not enclosed in a method.
     */
    public String outerMethod;

    /**
     * The descriptor of the method that contains the class, or <tt>null</tt> if
     * the class is not enclosed in a method.
     */
    public String outerMethodDesc;

    /**
     * The runtime visible annotations of this class. This list is a list of
     * {@link AnnotationNode} objects. May be <tt>null</tt>.
     *
     * @associates scala.tools.asm.tree.AnnotationNode
     * @label visible
     */
    public List<AnnotationNode> visibleAnnotations;

    /**
     * The runtime invisible annotations of this class. This list is a list of
     * {@link AnnotationNode} objects. May be <tt>null</tt>.
     *
     * @associates scala.tools.asm.tree.AnnotationNode
     * @label invisible
     */
    public List<AnnotationNode> invisibleAnnotations;

    /**
     * The non standard attributes of this class. This list is a list of
     * {@link Attribute} objects. May be <tt>null</tt>.
     *
     * @associates scala.tools.asm.Attribute
     */
    public List<Attribute> attrs;

    /**
     * Informations about the inner classes of this class. This list is a list
     * of {@link InnerClassNode} objects.
     *
     * @associates scala.tools.asm.tree.InnerClassNode
     */
    public List<InnerClassNode> innerClasses;

    /**
     * The fields of this class. This list is a list of {@link FieldNode}
     * objects.
     *
     * @associates scala.tools.asm.tree.FieldNode
     */
    public List<FieldNode> fields;

    /**
     * The methods of this class. This list is a list of {@link MethodNode}
     * objects.
     *
     * @associates scala.tools.asm.tree.MethodNode
     */
    public List<MethodNode> methods;

    /**
     * Constructs a new {@link ClassNode}. <i>Subclasses must not use this
     * constructor</i>. Instead, they must use the {@link #ClassNode(int)}
     * version.
     */
    public ClassNode() {
        this(Opcodes.ASM4);
    }

    /**
     * Constructs a new {@link ClassNode}.
     *
     * @param api
     *            the ASM API version implemented by this visitor. Must be one
     *            of {@link Opcodes#ASM4}.
     */
    public ClassNode(final int api) {
        super(api);
        this.interfaces = new ArrayList<String>();
        this.innerClasses = new ArrayList<InnerClassNode>();
        this.fields = new ArrayList<FieldNode>();
        this.methods = new ArrayList<MethodNode>();
    }

    // ------------------------------------------------------------------------
    // Implementation of the ClassVisitor abstract class
    // ------------------------------------------------------------------------

    @Override
    public void visit(final int version, final int access, final String name,
            final String signature, final String superName,
            final String[] interfaces) {
        this.version = version;
        this.access = access;
        this.name = name;
        this.signature = signature;
        this.superName = superName;
        if (interfaces != null) {
            this.interfaces.addAll(Arrays.asList(interfaces));
        }
    }

    @Override
    public void visitSource(final String file, final String debug) {
        sourceFile = file;
        sourceDebug = debug;
    }

    @Override
    public void visitOuterClass(final String owner, final String name,
            final String desc) {
        outerClass = owner;
        outerMethod = name;
        outerMethodDesc = desc;
    }

    @Override
    public AnnotationVisitor visitAnnotation(final String desc,
            final boolean visible) {
        AnnotationNode an = new AnnotationNode(desc);
        if (visible) {
            if (visibleAnnotations == null) {
                visibleAnnotations = new ArrayList<AnnotationNode>(1);
            }
            visibleAnnotations.add(an);
        } else {
            if (invisibleAnnotations == null) {
                invisibleAnnotations = new ArrayList<AnnotationNode>(1);
            }
            invisibleAnnotations.add(an);
        }
        return an;
    }

    @Override
    public void visitAttribute(final Attribute attr) {
        if (attrs == null) {
            attrs = new ArrayList<Attribute>(1);
        }
        attrs.add(attr);
    }

    @Override
    public void visitInnerClass(final String name, final String outerName,
            final String innerName, final int access) {
        InnerClassNode icn = new InnerClassNode(name, outerName, innerName,
                access);
        innerClasses.add(icn);
    }

    @Override
    public FieldVisitor visitField(final int access, final String name,
            final String desc, final String signature, final Object value) {
        FieldNode fn = new FieldNode(access, name, desc, signature, value);
        fields.add(fn);
        return fn;
    }

    @Override
    public MethodVisitor visitMethod(final int access, final String name,
            final String desc, final String signature, final String[] exceptions) {
        MethodNode mn = new MethodNode(access, name, desc, signature,
                exceptions);
        methods.add(mn);
        return mn;
    }

    @Override
    public void visitEnd() {
    }

    // ------------------------------------------------------------------------
    // Accept method
    // ------------------------------------------------------------------------

    /**
     * Checks that this class node is compatible with the given ASM API version.
     * This methods checks that this node, and all its nodes 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}.
     */
    public void check(final int api) {
        // nothing to do
    }

    /**
     * Makes the given class visitor visit this class.
     *
     * @param cv
     *            a class visitor.
     */
    public void accept(final ClassVisitor cv) {
        // visits header
        String[] interfaces = new String[this.interfaces.size()];
        this.interfaces.toArray(interfaces);
        cv.visit(version, access, name, signature, superName, interfaces);
        // visits source
        if (sourceFile != null || sourceDebug != null) {
            cv.visitSource(sourceFile, sourceDebug);
        }
        // visits outer class
        if (outerClass != null) {
            cv.visitOuterClass(outerClass, outerMethod, outerMethodDesc);
        }
        // visits attributes
        int i, n;
        n = visibleAnnotations == null ? 0 : visibleAnnotations.size();
        for (i = 0; i < n; ++i) {
            AnnotationNode an = visibleAnnotations.get(i);
            an.accept(cv.visitAnnotation(an.desc, true));
        }
        n = invisibleAnnotations == null ? 0 : invisibleAnnotations.size();
        for (i = 0; i < n; ++i) {
            AnnotationNode an = invisibleAnnotations.get(i);
            an.accept(cv.visitAnnotation(an.desc, false));
        }
        n = attrs == null ? 0 : attrs.size();
        for (i = 0; i < n; ++i) {
            cv.visitAttribute(attrs.get(i));
        }
        // visits inner classes
        for (i = 0; i < innerClasses.size(); ++i) {
            innerClasses.get(i).accept(cv);
        }
        // visits fields
        for (i = 0; i < fields.size(); ++i) {
            fields.get(i).accept(cv);
        }
        // visits methods
        for (i = 0; i < methods.size(); ++i) {
            methods.get(i).accept(cv);
        }
        // visits end
        cv.visitEnd();
    }
}