Alexander Lucas | 97842ff | 2014-03-07 14:56:55 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2012 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 | import android.util.Log; |
| 19 | |
| 20 | /** |
| 21 | * Helper class which wraps Android's native Log utility in the Logger interface. This way |
| 22 | * normal DDMS output can be one of the many targets receiving and outputting logs simultaneously. |
| 23 | */ |
| 24 | public class LogWrapper implements LogNode { |
| 25 | |
| 26 | // For piping: The next node to receive Log data after this one has done its work. |
| 27 | private LogNode mNext; |
| 28 | |
| 29 | /** |
| 30 | * Returns the next LogNode in the linked list. |
| 31 | */ |
| 32 | public LogNode getNext() { |
| 33 | return mNext; |
| 34 | } |
| 35 | |
| 36 | /** |
| 37 | * Sets the LogNode data will be sent to.. |
| 38 | */ |
| 39 | public void setNext(LogNode node) { |
| 40 | mNext = node; |
| 41 | } |
| 42 | |
| 43 | /** |
| 44 | * Prints data out to the console using Android's native log mechanism. |
| 45 | * @param priority Log level of the data being logged. Verbose, Error, etc. |
| 46 | * @param tag Tag for for the log data. Can be used to organize log statements. |
| 47 | * @param msg The actual message to be logged. The actual message to be logged. |
| 48 | * @param tr If an exception was thrown, this can be sent along for the logging facilities |
| 49 | * to extract and print useful information. |
| 50 | */ |
| 51 | @Override |
| 52 | public void println(int priority, String tag, String msg, Throwable tr) { |
| 53 | // There actually are log methods that don't take a msg parameter. For now, |
| 54 | // if that's the case, just convert null to the empty string and move on. |
| 55 | String useMsg = msg; |
| 56 | if (useMsg == null) { |
| 57 | useMsg = ""; |
| 58 | } |
| 59 | |
| 60 | // If an exeption was provided, convert that exception to a usable string and attach |
| 61 | // it to the end of the msg method. |
| 62 | if (tr != null) { |
| 63 | msg += "\n" + Log.getStackTraceString(tr); |
| 64 | } |
| 65 | |
| 66 | // This is functionally identical to Log.x(tag, useMsg); |
| 67 | // For instance, if priority were Log.VERBOSE, this would be the same as Log.v(tag, useMsg) |
| 68 | Log.println(priority, tag, useMsg); |
| 69 | |
| 70 | // If this isn't the last node in the chain, move things along. |
| 71 | if (mNext != null) { |
| 72 | mNext.println(priority, tag, msg, tr); |
| 73 | } |
| 74 | } |
| 75 | } |