001 /*
002 * Copyright (c) OSGi Alliance (2000, 2008). All Rights Reserved.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016 package org.osgi.service.log;
017
018 import org.osgi.framework.Bundle;
019 import org.osgi.framework.ServiceReference;
020
021 /**
022 * Provides methods to access the information contained in an individual Log
023 * Service log entry.
024 *
025 * <p>
026 * A <code>LogEntry</code> object may be acquired from the
027 * <code>LogReaderService.getLog</code> method or by registering a
028 * <code>LogListener</code> object.
029 *
030 * @ThreadSafe
031 * @version $Revision: 5654 $
032 * @see LogReaderService#getLog
033 * @see LogListener
034 */
035 public interface LogEntry {
036 /**
037 * Returns the bundle that created this <code>LogEntry</code> object.
038 *
039 * @return The bundle that created this <code>LogEntry</code> object;
040 * <code>null</code> if no bundle is associated with this
041 * <code>LogEntry</code> object.
042 */
043 public Bundle getBundle();
044
045 /**
046 * Returns the <code>ServiceReference</code> object for the service associated
047 * with this <code>LogEntry</code> object.
048 *
049 * @return <code>ServiceReference</code> object for the service associated
050 * with this <code>LogEntry</code> object; <code>null</code> if no
051 * <code>ServiceReference</code> object was provided.
052 */
053 public ServiceReference getServiceReference();
054
055 /**
056 * Returns the severity level of this <code>LogEntry</code> object.
057 *
058 * <p>
059 * This is one of the severity levels defined by the <code>LogService</code>
060 * interface.
061 *
062 * @return Severity level of this <code>LogEntry</code> object.
063 *
064 * @see LogService#LOG_ERROR
065 * @see LogService#LOG_WARNING
066 * @see LogService#LOG_INFO
067 * @see LogService#LOG_DEBUG
068 */
069 public int getLevel();
070
071 /**
072 * Returns the human readable message associated with this <code>LogEntry</code>
073 * object.
074 *
075 * @return <code>String</code> containing the message associated with this
076 * <code>LogEntry</code> object.
077 */
078 public String getMessage();
079
080 /**
081 * Returns the exception object associated with this <code>LogEntry</code>
082 * object.
083 *
084 * <p>
085 * In some implementations, the returned exception may not be the original
086 * exception. To avoid references to a bundle defined exception class, thus
087 * preventing an uninstalled bundle from being garbage collected, the Log
088 * Service may return an exception object of an implementation defined
089 * Throwable subclass. The returned object will attempt to provide as much
090 * information as possible from the original exception object such as the
091 * message and stack trace.
092 *
093 * @return <code>Throwable</code> object of the exception associated with this
094 * <code>LogEntry</code>;<code>null</code> if no exception is
095 * associated with this <code>LogEntry</code> object.
096 */
097 public Throwable getException();
098
099 /**
100 * Returns the value of <code>currentTimeMillis()</code> at the time this
101 * <code>LogEntry</code> object was created.
102 *
103 * @return The system time in milliseconds when this <code>LogEntry</code>
104 * object was created.
105 * @see "System.currentTimeMillis()"
106 */
107 public long getTime();
108 }