AbstractMethodRefConstant.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.utility.classfile;

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;

import org.eclipse.persistence.tools.workbench.utility.classfile.descriptor.FieldType;
import org.eclipse.persistence.tools.workbench.utility.classfile.tools.ClassFileDataInputStream;


/**
 * There's not much difference between a "method ref" and an
 * "interface method ref".
 */
public abstract class AbstractMethodRefConstant extends MemberRefConstant {
    private FieldType returnDescriptor;        // lazy-initialized - so use the getter
    private FieldType[] parameterDescriptors;        // lazy-initialized - so use the getter

    /**
     * Construct a class file constant from the specified stream
     * of byte codes.
     */
    AbstractMethodRefConstant(ConstantPool pool, byte tag, ClassFileDataInputStream stream) throws IOException {
        super(pool, tag, stream);
    }

    public boolean isConstructor() {
        return this.name().equals(Method.CONSTRUCTOR_NAME);
    }

    public boolean isStaticInitializationMethod() {
        return this.name().equals(Method.STATIC_INITIALIZER_NAME);
    }

    public void accept(Visitor visitor) {
        this.getReturnDescriptor().accept(visitor);
        FieldType[] ptds = this.getParameterDescriptors();
        int len = ptds.length;
        for (int i = 0; i < len; i++) {
            ptds[i].accept(visitor);
        }
    }

    public FieldType getReturnDescriptor() {
        if (this.returnDescriptor == null) {
            this.buildDescriptors();
        }
        return this.returnDescriptor;
    }

    public FieldType[] getParameterDescriptors() {
        if (this.parameterDescriptors == null) {
            this.buildDescriptors();
        }
        return this.parameterDescriptors;
    }

    public FieldType getParameterDescriptor(int index) {
        if (this.parameterDescriptors == null) {
            this.buildDescriptors();
        }
        return this.parameterDescriptors[index];
    }

    private void buildDescriptors() {
        Reader reader = new StringReader(this.descriptor());
        try {
            this.parameterDescriptors = Method.buildParameterDescriptors(reader);
            this.returnDescriptor = FieldType.createFieldType(reader);
        } catch (IOException ex) {
            // this is unlikely when reading a String
            throw new RuntimeException(ex);
        }
    }

}