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 java.io.Serializable;
023
024/**
025 * Handles messages that contain an Object.
026 */
027public class ObjectMessage implements Message {
028
029    private static final long serialVersionUID = -5903272448334166185L;
030
031    private transient Object obj;
032    private transient String objectString;
033
034    /**
035     * Create the ObjectMessage.
036     * @param obj The Object to format.
037     */
038    public ObjectMessage(Object obj) {
039        if (obj == null) {
040            obj = "null";
041        }
042        this.obj = obj;
043    }
044
045    /**
046     * Returns the formatted object message.
047     * @return the formatted object message.
048     */
049    @Override
050    public String getFormattedMessage() {
051        // LOG4J2-763: cache formatted string in case obj changes later
052        if (objectString == null) {
053            objectString = String.valueOf(obj);
054        }
055        return objectString;
056    }
057
058    /**
059     * Returns the object formatted using its toString method.
060     * @return the String representation of the object.
061     */
062    @Override
063    public String getFormat() {
064        return getFormattedMessage();
065    }
066
067    /**
068     * Returns the object as if it were a parameter.
069     * @return The object.
070     */
071    @Override
072    public Object[] getParameters() {
073        return new Object[] { obj };
074    }
075
076    @Override
077    public boolean equals(final Object o) {
078        if (this == o) {
079            return true;
080        }
081        if (o == null || getClass() != o.getClass()) {
082            return false;
083        }
084
085        final ObjectMessage that = (ObjectMessage) o;
086        return obj == null ? that.obj == null : equalObjectsOrStrings(obj, that.obj);
087    }
088    
089    private boolean equalObjectsOrStrings(Object left, Object right) {
090        return left.equals(right) || String.valueOf(left).equals(String.valueOf(right));
091    }
092
093    @Override
094    public int hashCode() {
095        return obj != null ? obj.hashCode() : 0;
096    }
097
098    @Override
099    public String toString() {
100        return "ObjectMessage[obj=" + getFormattedMessage() + ']';
101    }
102
103    private void writeObject(final ObjectOutputStream out) throws IOException {
104        out.defaultWriteObject();
105        if (obj instanceof Serializable) {
106            out.writeObject(obj);
107        } else {
108            out.writeObject(String.valueOf(obj));
109        }
110    }
111
112    private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
113        in.defaultReadObject();
114        obj = in.readObject();
115    }
116
117    /**
118     * Gets the message if it is a throwable.
119     *
120     * @return the message if it is a throwable.
121     */
122    @Override
123    public Throwable getThrowable() {
124        return obj instanceof Throwable ? (Throwable) obj : null;
125    }
126}