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     */
017    package org.apache.logging.log4j.message;
018    
019    import java.io.IOException;
020    import java.io.ObjectInputStream;
021    import java.io.ObjectOutputStream;
022    import java.io.Serializable;
023    
024    /**
025     * Handles messages that contain an Object.
026     */
027    public 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    }