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 *      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.apache.logging.log4j.message;
018
019import java.io.IOException;
020import java.io.ObjectInputStream;
021import java.io.ObjectOutputStream;
022import org.apache.logging.log4j.util.StringBuilderFormattable;
023
024/**
025 * The simplest possible implementation of Message. It just returns the String given as the constructor argument.
026 */
027public class SimpleMessage implements Message, StringBuilderFormattable, CharSequence {
028    private static final long serialVersionUID = -8398002534962715992L;
029
030    private String message;
031    private transient CharSequence charSequence;
032
033    /**
034     * Basic constructor.
035     */
036    public SimpleMessage() {
037        this(null);
038    }
039
040    /**
041     * Constructor that includes the message.
042     * @param message The String message.
043     */
044    public SimpleMessage(final String message) {
045        this.message = message;
046        this.charSequence = message;
047    }
048
049    /**
050     * Constructor that includes the message.
051     * @param charSequence The CharSequence message.
052     */
053    public SimpleMessage(final CharSequence charSequence) {
054        // this.message = String.valueOf(charSequence); // postponed until getFormattedMessage
055        this.charSequence = charSequence;
056    }
057
058    /**
059     * Returns the message.
060     * @return the message.
061     */
062    @Override
063    public String getFormattedMessage() {
064        if (message == null) {
065            message = String.valueOf(charSequence);
066        }
067        return message;
068    }
069
070    @Override
071    public void formatTo(final StringBuilder buffer) {
072        buffer.append(charSequence);
073    }
074
075    /**
076     * Returns the message.
077     * @return the message.
078     */
079    @Override
080    public String getFormat() {
081        return getFormattedMessage();
082    }
083
084    /**
085     * Returns null since there are no parameters.
086     * @return null.
087     */
088    @Override
089    public Object[] getParameters() {
090        return null;
091    }
092
093    @Override
094    public boolean equals(final Object o) {
095        if (this == o) {
096            return true;
097        }
098        if (o == null || getClass() != o.getClass()) {
099            return false;
100        }
101
102        final SimpleMessage that = (SimpleMessage) o;
103
104        return !(charSequence != null ? !charSequence.equals(that.charSequence) : that.charSequence != null);
105    }
106
107    @Override
108    public int hashCode() {
109        return charSequence != null ? charSequence.hashCode() : 0;
110    }
111
112    @Override
113    public String toString() {
114        return getFormattedMessage();
115    }
116
117    /**
118     * Always returns null.
119     *
120     * @return null
121     */
122    @Override
123    public Throwable getThrowable() {
124        return null;
125    }
126
127
128    // CharSequence impl
129
130    @Override
131    public int length() {
132        return charSequence == null ? 0 : charSequence.length();
133    }
134
135    @Override
136    public char charAt(final int index) {
137        return charSequence.charAt(index);
138    }
139
140    @Override
141    public CharSequence subSequence(final int start, final int end) {
142        return charSequence.subSequence(start, end);
143    }
144
145
146    private void writeObject(final ObjectOutputStream out) throws IOException {
147        getFormattedMessage(); // initialize the message:String field
148        out.defaultWriteObject();
149    }
150
151    private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
152        in.defaultReadObject();
153        charSequence = message;
154    }
155}