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CardEmulation / src / com.example.android.common / logger /

LogWrapper.java

       
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        /*
       
       
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        * Copyright (C) 2012 The Android Open Source Project
       
       
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        *
       
       
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        * Licensed under the Apache License, Version 2.0 (the "License");
       
       
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        * you may not use this file except in compliance with the License.
       
       
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        * You may obtain a copy of the License at
       
       
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        *
       
       
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        *      http://www.apache.org/licenses/LICENSE-2.0
       
       
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        *
       
       
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        * Unless required by applicable law or agreed to in writing, software
       
       
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        * distributed under the License is distributed on an "AS IS" BASIS,
       
       
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        * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       
       
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        * See the License for the specific language governing permissions and
       
       
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        * limitations under the License.
       
       
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        */
       
       
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        package com.example.android.common.logger;
       
       
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        import android.util.Log;
       
       
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        /**
       
       
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        * Helper class which wraps Android's native Log utility in the Logger interface.  This way
       
       
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        * normal DDMS output can be one of the many targets receiving and outputting logs simultaneously.
       
       
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        */
       
       
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        public class LogWrapper implements LogNode {
       
       
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        // For piping:  The next node to receive Log data after this one has done its work.
       
       
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        private LogNode mNext;
       
       
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        /**
       
       
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        * Returns the next LogNode in the linked list.
       
       
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        */
       
       
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        public LogNode getNext() {
       
       
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        return mNext;
       
       
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        }
       
       
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        /**
       
       
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        * Sets the LogNode data will be sent to..
       
       
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        */
       
       
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        public void setNext(LogNode node) {
       
       
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        mNext = node;
       
       
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        }
       
       
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        /**
       
       
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        * Prints data out to the console using Android's native log mechanism.
       
       
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        * @param priority Log level of the data being logged.  Verbose, Error, etc.
       
       
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        * @param tag Tag for for the log data.  Can be used to organize log statements.
       
       
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        * @param msg The actual message to be logged. The actual message to be logged.
       
       
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        * @param tr If an exception was thrown, this can be sent along for the logging facilities
       
       
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        *           to extract and print useful information.
       
       
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        */
       
       
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        @Override
       
       
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        public void println(int priority, String tag, String msg, Throwable tr) {
       
       
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        // There actually are log methods that don't take a msg parameter.  For now,
       
       
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        // if that's the case, just convert null to the empty string and move on.
       
       
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        String useMsg = msg;
       
       
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        if (useMsg == null) {
       
       
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        useMsg = "";
       
       
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        }
       
       
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        // If an exeption was provided, convert that exception to a usable string and attach
       
       
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        // it to the end of the msg method.
       
       
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        if (tr != null) {
       
       
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        msg += "\n" + Log.getStackTraceString(tr);
       
       
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        }
       
       
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        // This is functionally identical to Log.x(tag, useMsg);
       
       
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        // For instance, if priority were Log.VERBOSE, this would be the same as Log.v(tag, useMsg)
       
       
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        Log.println(priority, tag, useMsg);
       
       
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        // If this isn't the last node in the chain, move things along.
       
       
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        if (mNext != null) {
       
       
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        mNext.println(priority, tag, msg, tr);
       
       
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        }
       
       
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        }
       
       
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        }