    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      https://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.pool2;
    018
    019/**
    020 * A base class for common functionality.
    021 *
    022 * @since 2.4.3
    023 */
    024public abstract class BaseObject {
    025
    026    /**
    027     * Constructs a new instance.
    028     */
    029    public BaseObject() {
    030        // empty
    031    }
    032
    033    @Override
    034    public String toString() {
    035        final StringBuilder builder = new StringBuilder();
    036        builder.append(getClass().getSimpleName());
    037        builder.append(" [");
    038        toStringAppendFields(builder);
    039        builder.append("]");
    040        return builder.toString();
    041    }
    042
    043    /**
    044     * Used by sub-classes to include the fields defined by the sub-class in the
    045     * {@link #toString()} output.
    046     *
    047     * @param builder Field names and values are appended to this object
    048     */
    049    protected void toStringAppendFields(final StringBuilder builder) {
    050        // do nothing by default, needed for b/w compatibility.
    051    }
    052}