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