HyperLog Android

• Overview
• Log format
• Download
• Initialize
• Usage
• Get Logs in a File
• Push Logs Files to Remote Server
  • Sample Testing Endpoint using RequestBin
  • Example Testing Endpoint inside Django
• Custom Log Message Format
• Additional Methods
• Contribute
• About HyperTrack
• License

Overview

A utility logger library for Android on top of standard Android Log class for debugging purpose. This is a simple library that will allow Android apps or library to store log into database so that developer can pull the logs from the database into File or push the logs to your remote server for debugging purpose. Want to know more on this and wondering why you should prefer using this library over doing it yourself. Check out the blog post or sample apk.

Log Format

timeStamp + " | " + appVersion + " : " + osVersion + " | " + deviceUUID + " | [" + logLevelName + "]: " + message

2017-10-05T14:46:36.541Z 1.0 | 0.0.1 : Android-7.1.1 | 62bb1162466c3eed | [INFO]: Log has been pushed

Download

Download the latest version or grab via Gradle.

The library is available on mavenCentral() and jcenter(). In your module's build.gradle, add the following code snippet and run the gradle-sync.

dependencies {
    ...
    compile 'com.hypertrack:hyperlog:0.0.7'
    ...
}

Initialize

Inside onCreate of Application class or Launcher Activity.

HyperLog.initialize(this);
HyperLog.setLogLevel(Log.VERBOSE);

Usage

HyperLog.d(TAG,"Debug Log");

Get Logs in a File

File file = HyperLog.getDeviceLogsInFile(this);

Push Logs Files to Remote Server

Logs file can be pushed to your remote server or RequestBin(for testing) or to Logstash.

Steps:

1. Set the API Endpoint URL HyperLog.setURL before calling HyperLog.pushLogs method otherwise exception will be thrown. Developers can also set a testing endpoint using RequestBin.

HyperLog.setURL("API URL");

2. Push Logs file to the given endpoint.

HyperLog.pushLogs(this, false, new HLCallback() {
            @Override
            public void onSuccess(@NonNull Object response) {

            }

            @Override
            public void onError(@NonNull VolleyError HLErrorResponse) {

            }
});

Follow steps to setup testing endpoint at RequestBin

1. Visit the RequestBin site and create a RequestBin.
2. Once you have the bin created, copy the URL and set it to the HyperLog.setURL.
3. Now call HyperLog.pushLogs to push the logs file to given endpoint. This is asynchronous call.
4. After HyperLog.pushLogs success, reload the requestbin page to view exactly which requests were made, what headers were sent, and raw body and so on, all in a pretty graphical setting like below image.
5. Once you get the logs on RequestBin create your own endpoint on your server and start receiving logs on to your server for debugging.
6. (Optional) From your server you can directly push those to Logstash (part of ELK stack). We have discussed ELK in one of our blog.

Request Bin Sample Response

Setup example endpoint inside Django

The example code below will set you up with a view that can handle uploaded log files, decompress gzip, and print the contents of the file.

from rest_framework import views

class SDKLogFileAPIView(views.APIView):
    '''
    SDK Log endpoint for file uploads

    Example curl call:
    curl -i -X POST
            -H "Content-Type: multipart/form-data"
            -H "Authorization: token pk_e6c9cf663714fb4b96c12d265df554349e0db79b"
            -H "Content-Disposition: attachment; filename=upload.txt"
            -F "data=@/Users/Arjun/Desktop/filename.txt"
            localhost:8000/api/v1/logs/
    '''
    parser_classes = (
        parsers.FileUploadParser,
    )

    def post(self, request):
        '''
        Prints logs to stdout (accepts file)
        '''
        if request.FILES:
            device_id = self.request.META.get('HTTP_DEVICE_ID', 'None')
            user_agent = self.request.META.get('HTTP_USER_AGENT', 'None')
            expect_header = self.request.META.get('HTTP_EXPECT', 'None')
            file_obj = request.FILES['file']
            logger.info('Received log file of size %s bytes from device id: %s and user agent: %s and expect header: %s' %
                        (str(file_obj.size), device_id, user_agent, expect_header))
            self.decompress_file(file_obj)

        return Response({})

    def decompress_file(self, f):
        '''
        Decompress the gzip file and then print it to stdout
        so that logstash can pick it up. In case Content-Encoding
        is not gzip, then the normal method picks up the file.
        '''
        if not self.request.META.get('HTTP_CONTENT_ENCODING') == 'gzip':
            return self.handle_uploaded_file(f)

        result = StringIO.StringIO()

        for chunk in f.chunks():
            result.write(chunk)

        stringified_value = result.getvalue()
        result.close()
        decompressor = zlib.decompressobj(16 + zlib.MAX_WBITS)
        decompressed = decompressor.decompress(stringified_value)

        for line in decompressed.split('\n'):
            print line

    def handle_uploaded_file(self, f):
        '''
        Handle django file to print, so that logstash
        can pick it up.
        '''
        for chunk in f.chunks():
            lines = chunk.split('\n')

            for line in lines:
                print line

Note:

• Push logs file to server in compressed form to reduce the data consumption and response time.

HyperLog.pushLogs(Context mContext, boolean compress, HyperLogCallback callback);

• Logs will be compressed using GZIP encoding.
• Logs will be deleted from database after successful push.
• Logs will push to the server in batches. Each batch can have maximum of 5000 logs.

Custom Log Message Format

Default Log Message that will store in database.

timeStamp + " | " + appVersion + " : " + osVersion + " | " + deviceUUID + " | [" + logLevelName + "]: " + message

2017-10-05T14:46:36.541Z 1.0 | 0.0.1 : Android-7.1.1 | 62bb1162466c3eed | [INFO]: Log has been pushed

This message can easily be customize.

1. Create a new class extending LogFormat.
2. Override getFormattedLogMessage method.
3. Now return the formatted message.

class CustomLogMessageFormat extends LogFormat {

    CustomLog(Context context) {
        super(context);
    }

    public String getFormattedLogMessage(String logLevelName, String message, String timeStamp,
                                         String senderName, String osVersion, String deviceUUID) {
                                         
        //Custom Log Message Format                                
        String formattedMessage = timeStamp + " : " + logLevelName + " : " + deviceUUID + " : " + message;
        
        return formattedMessage;
    }
}

Custom Log Message Format example

2017-10-05T14:46:36.541Z 1.0 | INFO | 62bb1162466c3eed | Log has been pushed

4. Above created class instance then needs to be passed while initializing HyperLog or can be set later.

HyperLog.initialize(this,new CustomLogMessageFormat(this));
 
OR
 
HyperLog.initialize(this);
HyperLog.setLogFormat(new CustomLogMessageFormat(this));

Additional Methods

• Different types of log.

HyperLog.d(TAG,"debug");
HyperLog.i(TAG,"information");
HyperLog.e(TAG,"error");
HyperLog.v(TAG,"verbose");
HyperLog.w(TAG,"warning");
HyperLog.a(TAG,"assert");
HyperLog.exception(TAG,"exception",throwable);

• To check whether any device logs are available.

HyperLog.hasPendingDeviceLogs();

• Get the count of stored device logs.

HyperLog.logCount();

• Developer can pass additional headers along with API call while pushing logs to server.

HashMap<String, String> additionalHeaders = new HashMap<>();
additionalHeaders.put("Authorization","Token");
HyperLog.pushLogs(this, additionalHeaders, false, HLCallback);

• By default, seven days older logs will get delete automatically from the database. You can change the expiry period of logs by defining expiryTimeInSeconds.

HyperLog.initialize(@NonNull Context context, int expiryTimeInSeconds);

• Developers can also get the device log as a list of DeviceLog model or list of String .By default, fetched logs will delete from the database. Developers can override to change the default functionality.

HyperLog.getDeviceLogs(boolean deleteLogs);
HyperLog.getDeviceLogsInFile(Context mContext, boolean deleteLogs);

• By default, every get calls return data from first batch if there are one or more batch.
• If there are more than one batches then developer can gets the specific batch data by providing batch number.

HyperLog.getDeviceLogs(boolean deleteLogs, int batchNo);

• Get the number of batches using HyperLog.getDeviceLogBatchCount.
• Developer can manually delete the logs using HyperLog.deleteLogs.

Contribute

Please use the issues tracker to raise bug reports and feature requests. We'd love to see your pull requests, so send them in!

About HyperTrack

Developers use HyperTrack to build location features, not infrastructure. We reduce the complexity of building and operating location features to a few APIs that just work. Check it out. Sign up and start building! Join our Slack community for instant responses. You can also email us at help@hypertrack.io

License

MIT License

Copyright (c) 2016 HyperTrack

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.