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}