001/**
002 *
003 * Copyright 2020 Florian Schmaus
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://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.jivesoftware.smack.internal;
018
019import java.io.IOException;
020
021import org.jivesoftware.smack.util.ExtendedAppendable;
022
023public abstract class AbstractStats {
024
025    public final void appendStatsTo(Appendable appendable) throws IOException {
026        appendStatsTo(new ExtendedAppendable(appendable));
027    }
028
029    public abstract void appendStatsTo(ExtendedAppendable appendable) throws IOException;
030
031    private transient String toStringCache;
032
033    @Override
034    public final String toString() {
035        if (toStringCache != null) {
036            return toStringCache;
037        }
038
039        StringBuilder sb = new StringBuilder();
040        try {
041            appendStatsTo(sb);
042        } catch (IOException e) {
043            // Should never happen.
044            throw new AssertionError(e);
045        }
046
047        toStringCache =  sb.toString();
048
049        return toStringCache;
050    }
051
052}