CJLog

This library provides a lightweight, system independent logging facility to multiple destinations. Written in Kotlin, it can also be used in Java projects. A logging destination can be to a file, via HTTP to a local host, to the system's logging facility or wherever else you like - a new type of destination can be added by implementing a simple interface.

Installation

The library is available through Maven Central. Add this to your build.gradle

dependencies {
    implementation("com.control-j.cjlog:core:2.5-SNAPSHOT")
}

Alternatively you could:

1. Download a JAR file from one of the releases and add to your project libraries.
2. Clone the repository and add as a gradle sub-project;
3. Clone the repository and run gradlew build in the root, this will create build/libs/cjlog-1.1.jar - add this file to your project libraries.

Usage

In your application startup setup some parameters and add destinations. For example

        CJLog.deviceId = this.javaClass.simpleName + "-" + deviceName.replace(' ', '_')
        CJLog.isDebug = isDebugBuild
        CJLog.add(FileLogger(File(tmpdir, "app.log")))
        CJLog.captureErr()
        CJLog.add(FoundationLogger())
        logMsg("device is $model")
        // do http logging only for simulator or ad-hoc builds
        if (isDebugBuild)
            CJLog.add(HttpLogger())

In this example deviceName should previously have been set to an identifier for the device - on Android this would be Build.DEVICE. The value isDebugBuild is a boolean specifying whether this is a debug build, for example on Android this would be BuildConfig.DEBUG. Under RoboVM on iOS these functions will work:

        val isSimulator: Boolean by lazy {
            NSProcessInfo.getSharedProcessInfo().environment.containsKey("SIMULATOR_DEVICE_NAME")
        }
        val deviceName: String by lazy {
            if (isSimulator) NSProcessInfo.getSharedProcessInfo().environment["SIMULATOR_DEVICE_NAME"].toString()
            else UIDevice.getCurrentDevice().identifierForVendor.asString().takeLast(8)
        }

        val isDebugBuild: Boolean by lazy {
            isSimulator || NSBundle.getMainBundle().findResourcePath("embedded", "mobileprovision") != null
        }

In the above example a logfile is created using the call CJLog.add(FileLogger(File(tmpdir, "app.log"))). You can retrieve this file later via the property CJLog.logfiles The CJLog.captureErr() call allows the logger to capture and log anything printed to STDERR.

Another destination is added with CJLog.add(FoundationLogger()) - in this case FoundationLogger() creates an iOS Foundation logger - the source for FoundationLogger is:

class FoundationLogger : Destination {
    override fun sendMessage(deviceID: String, message: String) {
        Foundation.log(message.removeSuffix("\n"))
    }
}

The Android equivalent is:

class LogCatLogger : Destination {
    override fun sendMessage(deviceID: String, message: String) {
        Log.d(deviceID, message)
    }
}

The HttpLogger class will log to a suitably provisioned web server. This is typically used only in development to a local host - it does not implement any security. To set the destination URL set the HttpLogger.SYSLOGGER property.

Logging data

Logging a message is as simple as:

        CJLog.logMsg("Something failed $error")

or if you want to use String.format() style arguments:

      CJLog.logMsg("Got data %d length %d", value, length)

The method CJLog.debug() behaves identically to logMsg() except it only logs if the isDebug property is true. Exceptions can be logged with logException()

API Docs

Can be found here.