checkannotationadapter.java

jboss规则引擎

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2005 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 org.drools.asm.util;

import org.drools.asm.AnnotationVisitor;
import org.drools.asm.Type;

/**
 * An {@link AnnotationVisitor} that checks that its methods are properly used.
 * 
 * @author Eric Bruneton
 */
public class CheckAnnotationAdapter
    implements
    AnnotationVisitor {

    private AnnotationVisitor av;

    private boolean           named;

    private boolean           end;

    public CheckAnnotationAdapter(final AnnotationVisitor av) {
        this( av,
              true );
    }

    CheckAnnotationAdapter(final AnnotationVisitor av,
                           final boolean named) {
        this.av = av;
        this.named = named;
    }

    public void visit(final String name,
                      final Object value) {
        checkEnd();
        checkName( name );
        if ( !(value instanceof Byte || value instanceof Boolean || value instanceof Character || value instanceof Short || value instanceof Integer || value instanceof Long || value instanceof Float || value instanceof Double
               || value instanceof String || value instanceof Type || value instanceof byte[] || value instanceof boolean[] || value instanceof char[] || value instanceof short[] || value instanceof int[] || value instanceof long[]
               || value instanceof float[] || value instanceof double[]) ) {
            throw new IllegalArgumentException( "Invalid annotation value" );
        }
        this.av.visit( name,
                       value );
    }

    public void visitEnum(final String name,
                          final String desc,
                          final String value) {
        checkEnd();
        checkName( name );
        CheckMethodAdapter.checkDesc( desc,
                                      false );
        if ( value == null ) {
            throw new IllegalArgumentException( "Invalid enum value" );
        }
        this.av.visitEnum( name,
                           desc,
                           value );
    }

    public AnnotationVisitor visitAnnotation(final String name,
                                             final String desc) {
        checkEnd();
        checkName( name );
        CheckMethodAdapter.checkDesc( desc,
                                      false );
        return new CheckAnnotationAdapter( this.av.visitAnnotation( name,
                                                                    desc ) );
    }

    public AnnotationVisitor visitArray(final String name) {
        checkEnd();
        checkName( name );
        return new CheckAnnotationAdapter( this.av.visitArray( name ),
                                           false );
    }

    public void visitEnd() {
        checkEnd();
        this.end = true;
        this.av.visitEnd();
    }

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

    private void checkName(final String name) {
        if ( this.named && name == null ) {
            throw new IllegalArgumentException( "Annotation value name must not be null" );
        }
    }
}