How to extract an attribute from gradle.properties using bash

In some projects the version is written in the gradle.properties file using the attribute:
version=1.0.0-SNAPSHOT

I usually use this version as the version to be tagged in the Sonar server, for code analysis. This way, it is easier to have metrics more accurate when checking the new code against the previous release.

How to get the version. Alue using bash:
cat gradle.properties | “ˆ\sversion\s=“ | cut -d’=‘ -f2

And for the definition
version=1.0.0-SNAPSHOT

you should see
1.0.0-SNAPSHOT

How to get or display the project version from maven

When I am doing quality analysis on projects, one of the things I like to use is the real version of the project in Sonar.

How to extract it from maven projects?

mvn -q -Dexec.executable=echo -Dexec.args=‘${project.version}’ --non-recursive exec:exec

If your pom.xml has something like

You should see:
1.0.0-SNAPSHOT

Pass a parameter to all JVMs in a machine at the same time

JAVA_TOOL_OPTIONS

Imagine a scenario where you need to change a JVM parameter, but you can’t or is not a good solution to changing the start script of your server(s).

One of the challenges we had, when we were working with containers, was a way to change a parameter to a JVM without building the docker image again.
The application at the start time should read a JVM parameter where a _user profile_was defined.
For specific reasons we sometimes need to change this profile, for instance, to use a more controlled user where we can debug an issue. In these situations, we want to stop the container/pod, change the profile and start again, or even start a different container with a different profile.

As you know, the way to pass a JVM parameter to an application is
java -Dprofile=myValue com.some.Application appParameter1 appPaparameter2

What if I don’t have access, or is not viable to rewrite the above line?
You can add to the Environment variables of your operating system

JAVA_TOOL_OPTIONS=‘-Dvar1=value1 -Dvar2=value2’

Yes, you can add multiple values, since it is not a parameter, but an environment variable whose values will be injected into the JVM at starting time.

When the JVM starts it searches for this environment variable and uses it. You can check the output of the JVM displaying a message with the values found.

JDK_JAVA_OPTIONS

This environment variable has a different purpose, it adds its values as a prefix to the Java other values

Example

export JDK_JAVA_OPTIONS=‘-Dparam=value @someFile

When we execute this
java @otherFile

The real execution is
java -Dparam=value @somefile @otherFile

android

Android Adventures – Development Tips – Part 5

How to add the back button on the Activity Action Bar

If the character space stops working with EditBox when using Listeners
Probably it is the google keyboard trying to impose words instead of characters
The one solution that worked for me was to disable the text suggestions

android

Android Adventures-Development Tips-Part 4

How to remove the divider in a ListView?
What if my text doesn’t fit in a TextView?
How to return values from to the caller Activity?
Main Activity:
Highlight an item in a ListView

android

Android Adventures–Development Tips-Parte 3

How to shrink activity layout when virtual keyboard is displayed and hides some of the views?
There are several different solutions, one of them is:

– In the AndroidManifest.xml, for the target activity

android:windowSoftInputMode=”adjustResize”

If you use Database Room framework for SQLite management and Kotlin:

If you are using Kotlin don’t create a new method, you can have compilation errors on the generated class

java.lang.IllegalStateException: Cannot access database on the main thread since it may potentially lock the UI for a long period of time.
Solution 1: add allowMainThreadQueries

MyApp.database =  Room.databaseBuilder(this, AppDatabase::class.java, “MyDatabase”).allowMainThreadQueries().build()

Solution 2: Use another thread

Solution 3: If you use Kotlin 1.3+ you can use coroutines

How to explore a database in Android Emulator?
– You can copy the db files from the device to your computer and use a sqlite browser

– I use: Android Debug Database: https://github.com/amitshekhariitbhu/Android-Debug-Database

android

Android Adventures – Development Tips – Parte 2

How to add an icon to a button?
android:drawableLeft=”@android:drawable/ic_menu_search”
How to push a button in a LinearLayout to the right?
The trick in is the empty view

 

How to have an ImageButton transparent?
android:background=”@null”
How to clear all the Spannable styles in an EditText?
val currentPositionsInputText = contentTextEditBox.selectionStart
contentTextEditBox.setText(contentTextEditBox.text.toString())
android

Android Adventures – Development Tips

How to prevent an EditBox from expanding?

android:layout_width="0dp" – or height, depending the need and the use of the weight

android:layout_weight="1" – if you just have one and you want to fill the whole layout

How to add a Scrollbar to an EditBox?
android:scrollbars=”vertical”
How to write the text on top left of the EditBox?
android:gravity=”top|left”
How to avoid the overlap of the Toolbar with the included layout?
How to Highlight blocks of text in an EditBox?
Spannable spannable=new SpannableString(string);
// You can add other styles here, like bold, underline, other// if you are using a loop, put the Spannable construction outside the loop or sometimes only the last one will be used

spannable.setSpan(new ForegroundColorSpan(Color.BLUE), start, end, 0);
editText.setText(spannable);

Android SDK Tips

Little simple things where I lost some time finding out the resolution when developing for Android.

Emulator with PANIC error:

PANIC: Could not open: C:\Users\

This error happens all the time in windows environment. The most cause is because your username has some non-english characters like “éáç…”, and Android SDK uses your home folder in the operating system as a default to create the emulators.

Possible solution:

make a copy of the avd folder and configure the ini file to point to the new folder.

  1. Go to the emulator folder (for instance: c:\users\usernamewithnonenglishlike-áéíç\.android\avd\)
  2. Copy the “avd” folder to another folder without non-english characters (c:\myAvds\…")
    1. Don’t remove the original
  3. In the original folder open the “init” file: (for instance: c:\users\usernamewithnonenglishlike-á\.android\avd\AVD_for_2_7in_QVGA.ini)
  4. Change the path value to the new folder:
    1. path=newFolderWithoutNonEnglishCharacters\avd\AVD_for_2_7in_QVGA.avd
  5. Start the emulator, it must work now!

PS: Another way is creating manually the AVD and place it in a custom folder:

 

Associate the resource layout (xml file) with the Activity java class:

In the activity java file just add a line to link to the resource file.

Create your resource file or “design file” at res\layout\your_resource.xml

    1. use only lowercase characters combined with numbers and “_”
  1. In the Activity Java Class, in the “onCreate” method, use “setContentView(R.layout.your_resource) like the code below.











 

 

 

Can’t configure Android SDK in IntelliJ 12 when creating a new project

Intellij doesn’t have configured any jdk, so we must configure at least one!

  1. Create the project without the Android SDK configured.
  2. Add some jdk (1.5, 1.6, 1.7) in File->Project Structure
  3. Then choose Android SDK for your project!