1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package com.example.android.common.logger;
17 
18 /**
19  * Basic interface for a logging system that can output to one or more targets.
20  * Note that in addition to classes that will output these logs in some format,
21  * one can also implement this interface over a filter and insert that in the chain,
22  * such that no targets further down see certain data, or see manipulated forms of the data.
23  * You could, for instance, write a "ToHtmlLoggerNode" that just converted all the log data
24  * it received to HTML and sent it along to the next node in the chain, without printing it
25  * anywhere.
26  */
27 public interface LogNode {
28 
29     /**
30      * Instructs first LogNode in the list to print the log data provided.
31      *
32      * @param priority Log level of the data being logged.  Verbose, Error, etc.
33      * @param tag      Tag for for the log data.  Can be used to organize log statements.
34      * @param msg      The actual message to be logged. The actual message to be logged.
35      * @param tr       If an exception was thrown, this can be sent along for the logging
36      *                 facilities
37      *                 to extract and print useful information.
38      */
println(int priority, String tag, String msg, Throwable tr)39     public void println(int priority, String tag, String msg, Throwable tr);
40 
41 }
42