Java example source code file (ClassNode.java)

This example Java source code file (ClassNode.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

annotationnode, annotationvisitor, arraylist, classnode, classvisitor, fieldnode, innerclassnode, list, methodnode, methodvisitor, override, runtimeexception, string, typeannotationnode, util

The ClassNode.java Java example source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file:
 *
 * 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 jdk.internal.org.objectweb.asm.tree;

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

import jdk.internal.org.objectweb.asm.AnnotationVisitor;
import jdk.internal.org.objectweb.asm.Attribute;
import jdk.internal.org.objectweb.asm.ClassVisitor;
import jdk.internal.org.objectweb.asm.FieldVisitor;
import jdk.internal.org.objectweb.asm.MethodVisitor;
import jdk.internal.org.objectweb.asm.Opcodes;
import jdk.internal.org.objectweb.asm.TypePath;

/**
 * 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 jdk.internal.org.objectweb.asm.Opcodes}). This
     * field also indicates if the class is deprecated.
     */
    public int access;

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

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

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

    /**
     * The internal names of the class's interfaces (see
     * {@link jdk.internal.org.objectweb.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.
     */
    public String sourceFile;

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

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

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

    /**
     * The descriptor of the method that contains the class, or <tt>null 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.
     *
     * @associates jdk.internal.org.objectweb.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.
     *
     * @associates jdk.internal.org.objectweb.asm.tree.AnnotationNode
     * @label invisible
     */
    public List<AnnotationNode> invisibleAnnotations;

    /**
     * The runtime visible type annotations of this class. This list is a list
     * of {@link TypeAnnotationNode} objects. May be <tt>null.
     *
     * @associates jdk.internal.org.objectweb.asm.tree.TypeAnnotationNode
     * @label visible
     */
    public List<TypeAnnotationNode> visibleTypeAnnotations;

    /**
     * The runtime invisible type annotations of this class. This list is a list
     * of {@link TypeAnnotationNode} objects. May be <tt>null.
     *
     * @associates jdk.internal.org.objectweb.asm.tree.TypeAnnotationNode
     * @label invisible
     */
    public List<TypeAnnotationNode> invisibleTypeAnnotations;

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

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

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

    /**
     * The methods of this class. This list is a list of {@link MethodNode}
     * objects.
     *
     * @associates jdk.internal.org.objectweb.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.
     *
     * @throws IllegalStateException
     *             If a subclass calls this constructor.
     */
    public ClassNode() {
        this(Opcodes.ASM5);
        if (getClass() != ClassNode.class) {
            throw new IllegalStateException();
        }
    }

    /**
     * Constructs a new {@link ClassNode}.
     *
     * @param api
     *            the ASM API version implemented by this visitor. Must be one
     *            of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
     */
    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 AnnotationVisitor visitTypeAnnotation(int typeRef,
            TypePath typePath, String desc, boolean visible) {
        TypeAnnotationNode an = new TypeAnnotationNode(typeRef, typePath, desc);
        if (visible) {
            if (visibleTypeAnnotations == null) {
                visibleTypeAnnotations = new ArrayList<TypeAnnotationNode>(1);
            }
            visibleTypeAnnotations.add(an);
        } else {
            if (invisibleTypeAnnotations == null) {
                invisibleTypeAnnotations = new ArrayList<TypeAnnotationNode>(1);
            }
            invisibleTypeAnnotations.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} or
     *            {@link Opcodes#ASM5}.
     */
    public void check(final int api) {
        if (api == Opcodes.ASM4) {
            if (visibleTypeAnnotations != null
                    && visibleTypeAnnotations.size() > 0) {
                throw new RuntimeException();
            }
            if (invisibleTypeAnnotations != null
                    && invisibleTypeAnnotations.size() > 0) {
                throw new RuntimeException();
            }
            for (FieldNode f : fields) {
                f.check(api);
            }
            for (MethodNode m : methods) {
                m.check(api);
            }
        }
    }

    /**
     * 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 = visibleTypeAnnotations == null ? 0 : visibleTypeAnnotations.size();
        for (i = 0; i < n; ++i) {
            TypeAnnotationNode an = visibleTypeAnnotations.get(i);
            an.accept(cv.visitTypeAnnotation(an.typeRef, an.typePath, an.desc,
                    true));
        }
        n = invisibleTypeAnnotations == null ? 0 : invisibleTypeAnnotations
                .size();
        for (i = 0; i < n; ++i) {
            TypeAnnotationNode an = invisibleTypeAnnotations.get(i);
            an.accept(cv.visitTypeAnnotation(an.typeRef, an.typePath, 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();
    }
}