Scala example source code file (CheckFieldAdapter.java)

This example Scala source code file (CheckFieldAdapter.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

annotationvisitor, asm, attribute, cannot, checkfieldadapter, fieldvisitor, illegalargumentexception, illegalstateexception, invalid, override, string

The CheckFieldAdapter.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.util;

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

/**
 * A {@link FieldVisitor} that checks that its methods are properly used.
 */
public class CheckFieldAdapter extends FieldVisitor {

    private boolean end;

    /**
     * Constructs a new {@link CheckFieldAdapter}. <i>Subclasses must not use
     * this constructor</i>. Instead, they must use the
     * {@link #CheckFieldAdapter(int, FieldVisitor)} version.
     *
     * @param fv
     *            the field visitor to which this adapter must delegate calls.
     */
    public CheckFieldAdapter(final FieldVisitor fv) {
        this(Opcodes.ASM4, fv);
    }

    /**
     * Constructs a new {@link CheckFieldAdapter}.
     *
     * @param api
     *            the ASM API version implemented by this visitor. Must be one
     *            of {@link Opcodes#ASM4}.
     * @param fv
     *            the field visitor to which this adapter must delegate calls.
     */
    protected CheckFieldAdapter(final int api, final FieldVisitor fv) {
        super(api, fv);
    }

    @Override
    public AnnotationVisitor visitAnnotation(final String desc,
            final boolean visible) {
        checkEnd();
        CheckMethodAdapter.checkDesc(desc, false);
        return new CheckAnnotationAdapter(super.visitAnnotation(desc, visible));
    }

    @Override
    public void visitAttribute(final Attribute attr) {
        checkEnd();
        if (attr == null) {
            throw new IllegalArgumentException(
                    "Invalid attribute (must not be null)");
        }
        super.visitAttribute(attr);
    }

    @Override
    public void visitEnd() {
        checkEnd();
        end = true;
        super.visitEnd();
    }

    private void checkEnd() {
        if (end) {
            throw new IllegalStateException(
                    "Cannot call a visit method after visitEnd has been called");
        }
    }
}