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apache / logging-log4j-site / d0d0de55986756593c08e5d2b8059541eacaf428 / . / log4j-2.0-alpha1-SNAPSHOT / log4j-api / apidocs / src-html / org / apache / logging / log4j / message / Message.html
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<FONT color="green">001</FONT> /*<a name="line.1"></a>
<FONT color="green">002</FONT> * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT> * contributor license agreements. See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT> * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT> * The ASF licenses this file to You under the Apache license, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT> * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT> * the License. You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT> *<a name="line.8"></a>
<FONT color="green">009</FONT> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT> *<a name="line.10"></a>
<FONT color="green">011</FONT> * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT> * See the license for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT> * limitations under the license.<a name="line.15"></a>
<FONT color="green">016</FONT> */<a name="line.16"></a>
<FONT color="green">017</FONT> package org.apache.logging.log4j.message;<a name="line.17"></a>
<FONT color="green">018</FONT> <a name="line.18"></a>
<FONT color="green">019</FONT> import java.io.Serializable;<a name="line.19"></a>
<FONT color="green">020</FONT> <a name="line.20"></a>
<FONT color="green">021</FONT> /**<a name="line.21"></a>
<FONT color="green">022</FONT> * An interface for various Message implementations that can be logged. Messages can act as wrappers<a name="line.22"></a>
<FONT color="green">023</FONT> * around Objects so that user can have control over converting Objects to Strings when necessary without<a name="line.23"></a>
<FONT color="green">024</FONT> * requiring complicated formatters and as a way to manipulate the message based on information available<a name="line.24"></a>
<FONT color="green">025</FONT> * at runtime such as the locale of the system.<a name="line.25"></a>
<FONT color="green">026</FONT> *<a name="line.26"></a>
<FONT color="green">027</FONT> * Note: Message objects should not be considered to be thread safe nor should they be assumed to be<a name="line.27"></a>
<FONT color="green">028</FONT> * safely reusable even on the same thread. The logging system may provide information to the Message<a name="line.28"></a>
<FONT color="green">029</FONT> * objects and the Messages might be queued for asynchronous delivery. Thus, any modifications to a<a name="line.29"></a>
<FONT color="green">030</FONT> * Message object by an application should by avoided after the Message has been passed as a parameter on<a name="line.30"></a>
<FONT color="green">031</FONT> * a Logger method.<a name="line.31"></a>
<FONT color="green">032</FONT> * @doubt Interfaces should rarely extend Serializable according to Effective Java 2nd Ed pg 291.<a name="line.32"></a>
<FONT color="green">033</FONT> * (RG) That section also says "If a class or interface exists primarily to participate in a framework that<a name="line.33"></a>
<FONT color="green">034</FONT> * requires all participants to implement Serializable, then it makes perfect sense for the class or<a name="line.34"></a>
<FONT color="green">035</FONT> * interface to implement or extend Serializable". Such is the case here as the LogEvent must be Serializable.<a name="line.35"></a>
<FONT color="green">036</FONT> */<a name="line.36"></a>
<FONT color="green">037</FONT> public interface Message extends Serializable {<a name="line.37"></a>
<FONT color="green">038</FONT> /**<a name="line.38"></a>
<FONT color="green">039</FONT> * Returns the Message formatted as a String.<a name="line.39"></a>
<FONT color="green">040</FONT> *<a name="line.40"></a>
<FONT color="green">041</FONT> * @return The message String.<a name="line.41"></a>
<FONT color="green">042</FONT> */<a name="line.42"></a>
<FONT color="green">043</FONT> String getFormattedMessage();<a name="line.43"></a>
<FONT color="green">044</FONT> <a name="line.44"></a>
<FONT color="green">045</FONT> /**<a name="line.45"></a>
<FONT color="green">046</FONT> * Returns the format portion of the Message.<a name="line.46"></a>
<FONT color="green">047</FONT> *<a name="line.47"></a>
<FONT color="green">048</FONT> * @return The message format.<a name="line.48"></a>
<FONT color="green">049</FONT> * @doubt Do all messages have a format? What syntax? Using a Formatter object could be cleaner.<a name="line.49"></a>
<FONT color="green">050</FONT> * (RG) In SimpleMessage the format is identical to the formatted message. In ParameterizedMessage and<a name="line.50"></a>
<FONT color="green">051</FONT> * StructuredDataMessage itis not. It is up to the Message implementer to determine what this<a name="line.51"></a>
<FONT color="green">052</FONT> * method will return. A Formatter is inappropriate as this is very specific to the Message<a name="line.52"></a>
<FONT color="green">053</FONT> * implementation so it isn't clear to me how having a Formatter separate from the Message would be cleaner.<a name="line.53"></a>
<FONT color="green">054</FONT> */<a name="line.54"></a>
<FONT color="green">055</FONT> String getMessageFormat();<a name="line.55"></a>
<FONT color="green">056</FONT> <a name="line.56"></a>
<FONT color="green">057</FONT> /**<a name="line.57"></a>
<FONT color="green">058</FONT> * Returns parameter values, if any.<a name="line.58"></a>
<FONT color="green">059</FONT> *<a name="line.59"></a>
<FONT color="green">060</FONT> * @return An array of parameter values or null.<a name="line.60"></a>
<FONT color="green">061</FONT> */<a name="line.61"></a>
<FONT color="green">062</FONT> Object[] getParameters();<a name="line.62"></a>
<FONT color="green">063</FONT> }<a name="line.63"></a>
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