How to write build time stamp into apk

Question

1. Making some changes in Android Contacts package
2. Using mm (make) command to build this application

Because I have to change and

Answer 1

in your build.gradle:

android {
    defaultConfig {
        buildConfigField 'String', 'BUILD_TIME', 'new java.text.SimpleDateFormat("MM.dd.yy HH:mm", java.util.Locale.getDefault()).format(new java.util.Date(' + System.currentTimeMillis() +'L))'
    }
}

Answer 2

I use the same strategy as Pointer Null except I prefer the MANIFEST.MF file. This one is regenerated even if a layout is modified (which is not the case for classes.dex). I also force the date to be formated in GMT to avoid confusion between terminal and server TZs (if a comparison has to be made, ex: check latest version).

It result in the following code:

  try{
     ApplicationInfo ai = getPackageManager().getApplicationInfo(getPackageName(), 0);
     ZipFile zf = new ZipFile(ai.sourceDir);
     ZipEntry ze = zf.getEntry("META-INF/MANIFEST.MF");
     long time = ze.getTime();
     SimpleDateFormat formatter = (SimpleDateFormat) SimpleDateFormat.getInstance();
     formatter.setTimeZone(TimeZone.getTimeZone("gmt"));
     String s = formatter.format(new java.util.Date(time));
     zf.close();
  }catch(Exception e){
  }

Answer 3

For time stamping and versioning, build.gradle/android/defaultConfig:

def buildDateStamp = new Date().format("yyyyMMdd").toInteger()
versionCode buildDateStamp
versionName "$buildDateStamp"
buildConfigField "String", "BUILD_DATE_STAMP", "\"$buildDateStamp\""

Usage in code: BuildConfig.BUILD_DATE_STAMP

resValue "string", "build_date_stamp", "$buildDateStamp"

Usage in xml: "@string/build_date_stamp"

Caveat: adding HHmm will cause errors (probably integer overflow)

Answer 4

So Android Developer - Android Studio User Guide - Gradle Tips and Recipes - Simplify App Development actually documents what to add in order to have a release timestamp available to your app:

android {
  ...
  buildTypes {
    release {
      // These values are defined only for the release build, which
      // is typically used for full builds and continuous builds.
      buildConfigField("String", "BUILD_TIME", "\"${minutesSinceEpoch}\"")
      resValue("string", "build_time", "${minutesSinceEpoch}")
      ...
    }
    debug {
      // Use static values for incremental builds to ensure that
      // resource files and BuildConfig aren't rebuilt with each run.
      // If they were dynamic, they would prevent certain benefits of
      // Instant Run as well as Gradle UP-TO-DATE checks.
      buildConfigField("String", "BUILD_TIME", "\"0\"")
      resValue("string", "build_time", "0")
    }
  }
}
...

In your app code, you can access the properties as follows:

...
Log.i(TAG, BuildConfig.BUILD_TIME);
Log.i(TAG, getString(R.string.build_time));

I'm including this here since all of the other solutions appear to be from before the official example.

Answer 5

I know this is really old, but here's how I did it using ant within eclipse:

build.xml in project root

<project name="set_strings_application_build_date" default="set_build_date" basedir=".">
    <description>
        This ant script updates strings.xml application_build_date to the current date
    </description>

    <!-- set global properties for this build -->
    <property name="strings.xml"  location="./res/values/strings.xml"/>

    <target name="init">
        <!-- Create the time stamp -->
        <tstamp/>
    </target>

    <target name="set_build_date" depends="init" description="sets the build date" >

        <replaceregexp file="${strings.xml}"
            match="(&lt;string name=&quot;application_build_date&quot;&gt;)\d+(&lt;/string&gt;)"
            replace="&lt;string name=&quot;application_build_date&quot;&gt;${DSTAMP}&lt;/string&gt;" />

    </target>
</project>

Then add an application_build_date string to your strings.xml

<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
    <string name="app_name">your app name</string>
    <string name="application_build_date">20140101</string>
    ...
</resources>

Ensure the ant script is executed as a pre-build activity and you will always have a valid build date available to you within R.string.application_build_date.

Answer 6

Since API version 9 there's:

PackageInfo.lastUpdateTime

The time at which the app was last updated.

try {
    PackageInfo packageInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
    //TODO use packageInfo.lastUpdateTime
} catch (PackageManager.NameNotFoundException e) {
    e.printStackTrace();
}

On lower API versions you must make build time yourself. For example putting a file into assets folder containing the date. Or using __ DATE__ macro in native code. Or checking date when your classes.dex was built (date of file in your APK).