FieldPool.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.StringWriter;
import java.util.ArrayList;
import java.util.Collection;

import org.eclipse.persistence.tools.workbench.utility.ClassTools;
import org.eclipse.persistence.tools.workbench.utility.classfile.tools.ClassFileDataInputStream;
import org.eclipse.persistence.tools.workbench.utility.io.IndentingPrintWriter;


/**
 * This class models a class file field pool:
 *     u2 fields_count;
 *     field_info[fields_count] fields;
 *
 * See "The Java Virtual Machine Specification" Chapter 4.
 */
public class FieldPool implements Member.Pool {
    private ClassFile classFile;
    private short count;
    private Field[] fields;


    /**
     * Construct a class file field pool from the specified stream
     * of byte codes.
     */
    FieldPool(ClassFileDataInputStream stream, ClassFile classFile) throws IOException {
        super();
        this.classFile = classFile;
        this.initialize(stream);
    }

    private void initialize(ClassFileDataInputStream stream) throws IOException {
        this.count = stream.readU2();
        short cnt = this.count;
        this.fields = new Field[cnt];
        Field[] localFields = this.fields;
        for (short i = 0; i < cnt; i++) {
            localFields[i] = new Field(stream, this);
        }
    }

    public String displayString() {
        StringWriter sw = new StringWriter(1000);
        IndentingPrintWriter writer = new IndentingPrintWriter(sw);
        this.displayStringOn(writer);
        return sw.toString();
    }

    public void displayStringOn(IndentingPrintWriter writer) {
        short cnt = this.count;
        Field[] localFields = this.fields;
        writer.print("Field Pool (count: ");
        writer.print(cnt);
        writer.println(')');
        writer.indent();
        for (short i = 0; i < cnt; i++) {
            writer.print(i);
            writer.print(": ");
            localFields[i].displayStringOn(writer);
        }
        writer.undent();
    }

    public Field fieldNamed(String fieldName) {
        short cnt = this.count;
        Field[] localFields = this.fields;
        for (short i = 0; i < cnt; i++) {
            Field field = localFields[i];
            if (field.name().equals(fieldName)) {
                return field;
            }
        }
        throw new IllegalArgumentException(fieldName);
    }

    public Field[] declaredFields() {
        short cnt = this.count;
        Field[] localFields = this.fields;
        Collection declaredFields = new ArrayList(cnt);
        for (short i = 0; i < cnt; i++) {
            Field field = localFields[i];
            if (field.isDeclaredField()) {
                declaredFields.add(field);
            }
        }
        return (Field[]) declaredFields.toArray(new Field[declaredFields.size()]);
    }

    public void accept(Visitor visitor) {
        visitor.visit(this);
        short cnt = this.count;
        Field[] localFields = this.fields;
        for (short i = 0; i < cnt; i++) {
            localFields[i].accept(visitor);
        }
    }

    public ClassFile getClassFile() {
        return this.classFile;
    }

    public short getCount() {
        return this.count;
    }

    public Field get(short index) {
        return this.fields[index];
    }

    public Field[] getFields() {
        return this.fields;
    }

    public String toString() {
        return ClassTools.shortClassNameForObject(this) + '(' + this.count + " field(s))";
    }

}