Recompile with -Xlint in Android studio

Staying out of deprecated methods is useful, so your app won’t run in some compatibility mode on the device. Plus having clean build output is also nice 🙂

While building an app, Gradle may produces some warnings telling you that some input files are using unchecked or unsafe operations or they are overriding a deprecated API.

Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.

As the message suggest, we should recompile with -Xlint to get more details about the warnings.

In the app level build.gradle file

app level build.gradle file

we should add a section labelled  allprojects{}(if not already present).

In the allprojects{} section we will instruct Gradle to apply custom compiler arguments for each task involving  Java code compilation.

allprojects {
    tasks.withType(JavaCompile) {
        options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation"
    }
}

Now each time we build our app we will get detailed output of the unchecked or unsafe operations and the deprecated API we are using.

Tip: if for some reason we want to continue using a deprecated API and just suppress the warnings, we could annotate the deprecated method with the

@SuppressWarnings("deprecation")

annotation.

Auto ‘versionCode’ increment when building production apk’s

Android, Smartphone, Android Developer, Android Studio

Since I adopted Fabric as a way to monitor vital app stats such as ‘Time in App per User‘ and it’s Beta distribution platform to distribute test builds, increasing APK’s versionCode numbers became a tedious task.

I decided to simplify the things by letting Gradle to do auto versionCode increments when producing release APK’s

Our implementation of build number increments will consist of a property file named version.properties located in the root folder of our project.

The property file will contain 2 variables, one defining the version name such as “2.3” and one defining the version code such as 15

VERSION_NAME=2.3
VERSION_CODE=19

In our app module build.gradle file

build.gradle

we will define a function which takes care of retrieving the a bough mentioned values from the properties file and increment the VERSION_CODE if needed.

/**
 * Get's value from 'version.properties' file
 * @param varName the name of the variable which value we wan't to get.
 * @return the variable value.
 */
def getVersionPropertiesValue(def varName)
{
    def propertiesFile = file('version.properties')
 
    if(!propertiesFile.canRead()) {
        throw new GradleException("Could not read " + propertiesFile.name)
    }
 
    Properties properties = new Properties();
    properties.load(new FileInputStream(propertiesFile))
 
    def propertyValue = properties[varName]
    if(varName == 'VERSION_CODE')
    {
        // If we are building release increment the version code
        List gradleTasksNames = gradle.startParameter.getTaskNames();
        for(String taskName : gradleTasksNames)
        {
            if(taskName.contains("Release"))
            {
                propertyValue = propertyValue.toInteger() + 1
                properties[varName] = propertyValue.toString()
                properties.store(propertiesFile.newWriter(), null)
                break
            }
        }
    }
 
    return propertyValue
}

In the defaultConfig section of the gradle build script we will call this function to retrieve values for the versionName and versionCode of our app.

android {
    compileSdkVersion 28
 
    defaultConfig {
        applicationId "com.example.foo"
        versionCode Integer.valueOf(getVersionPropertiesValue('VERSION_CODE'))
        versionName getVersionPropertiesValue('VERSION_NAME')
        minSdkVersion 14
        targetSdkVersion 28
    }
}

Now each time a release build is made, the version code will increment automatically. If we want to change the version name we can do so by changing the value of VERSION_NAME property.

TortoiseGIT Disconnected: No supported authentication methods available ( server sent: publickey )

After migrating to SSH authentication for my Bitbucket repo ( one of the reasons for doing that was to be able to mirror my repo on my home server, article on that topic coming soon ), the TortoiseGIT windows client stopped working. It was unable to do pulls and pushes and all other functionallity related to connecting to the remote GIT. Android Studio and other IDE’s and tools I use on a daily basis, including git command line client were working properly.

Untitled1

TortoiseGIT uses Pageant (part of the PuTTY toolset) to manage it’s authentication keys. Because I have already generated the public / private key pair using ssh-keygen all I needed to do was make Pageant aware of them.

For this Puttygen (part of the PuTTY toolset) should be used.

Untitled4

pass

Load the key in Puttygen (you will be prompted for password during the loading process), leave the default settings. If the import was successful you will get a message telling you so.

success

Then click ‘Save private key’ button and save your private key in putty default ppk format. Fire up Pageant and load your newly created key.

Untitled6

Now pulls, pushes and all other functionallity related to connecting to the remote GIT should work as expected.

Untitled7

NOTE: Pageant should be started prior to using TortoiseGIT, else you will get the same error message again.

Get Android Studio debug certificate fingerprints on Windows

Here is a small batch file that will retrieve Android Studio debug certificate fingerprints. Make sure that keytool.exe is in your %PATH%

@echo off
keytool -list -v -keystore "%USERPROFILE%\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android
pause

Copy / paste the a bough commands in an empty file and save it with a .bat extension.

Android Studio debug certificate fingerprints
Android Studio debug certificate fingerprints