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 * 46 * @param priority Log level of the data being logged. Verbose, Error, etc. 47 * @param tag Tag for for the log data. Can be used to organize log statements. 48 * @param msg The actual message to be logged. The actual message to be logged. 49 * @param tr If an exception was thrown, this can be sent along for the logging 50 * facilities 51 * to extract and print useful information. 52 */ 53 @Override 54 public void println(int priority, String tag, String msg, Throwable tr) { 55 // There actually are log methods that don't take a msg parameter. For now, 56 // if that's the case, just convert null to the empty string and move on. 57 String useMsg = msg; 58 if (useMsg == null) { 59 useMsg = ""; 60 } 61 62 // If an exeption was provided, convert that exception to a usable string and attach 63 // it to the end of the msg method. 64 if (tr != null) { 65 msg += "\n" + Log.getStackTraceString(tr); 66 } 67 68 // This is functionally identical to Log.x(tag, useMsg); 69 // For instance, if priority were Log.VERBOSE, this would be the same as Log.v(tag, useMsg) 70 Log.println(priority, tag, useMsg); 71 72 // If this isn't the last node in the chain, move things along. 73 if (mNext != null) { 74 mNext.println(priority, tag, msg, tr); 75 } 76 } 77 } 78
