How To Use Java In Android Studio


Creating Your Game View

Run a Java application in Android Studio

You may be used to apps that use an XML script to define the layout of views like buttons, images and labels. This is what the line setContentView is doing for us.

But again, this is a game meaning it doesnt need to have browser windows or scrolling recycler views. Instead of that, we want to show a canvas instead. In Android Studio a canvas is just the same as it is in art: its a medium that we can draw on.

So change that line to read as so:


Youll find that this is once again underlined red. But now if you press Alt+Enter, you dont have the option to import the class. Instead, you have the option to create a class. In other words, were about to make our own class that will define whats going to go on the canvas. This is what will allow us to draw to the screen, rather than just showing ready-made views.

So right click on the package name in your hierarchy over on the left and choose New > Class. Youll now be presented with a window to create your class and youre going to call it GameView. Under SuperClass, write: android.view.SurfaceView which means that the class will inherit methods its capabilities from SurfaceView.

In the Interface box, youll write android.view.SurfaceHolder.Callback. As with any class, we now need to create our constructor. Use this code:

private MainThread thread public GameView 

Now override some methods:

Mac Os X 106 Snow Leopard

Mac OS X 10.6 Snow Leopard was released on August 28, 2009. Rather than delivering big changes to the appearance and end user functionality like the previous releases of Mac OS X, Snow Leopard focused on “under the hood” changes, increasing the performance, efficiency, and stability of the operating system. For most users, the most noticeable changes were: the disk space that the operating system frees up after a clean install compared to Mac OS X 10.5 Leopard, a more responsive rewritten in , faster backups, more reliable and user-friendly disk ejects, a more powerful version of the Preview application, as well as a faster web browser. Snow Leopard only supported machines with Intel CPUs, required at least 1 GB of , and dropped default support for applications built for the architecture ” rel=”nofollow”> Rosetta could be installed as an additional component to retain support for PowerPC-only applications).

Snow Leopard also featured new technology capable of supporting greater amounts of , improved support for multi-core processors through , and advanced GPU performance with .

The 10.6.6 update introduced support for the , Apple’s digital distribution platform for macOS applications.

Easy To Learn And Use Language

The main reason for choosing Java app development is that it has a steep learning curve for building mobile applications. In the case of most professional programs, it is difficult to get this programming language productive in a short period of time.

Like Basic English language, Java has familiar English punctuation with least excellent characters. Generics, for example, have angle brackets that make coding easy to read and comprehend.

Moreover Java is free to get started with, you dont have to spend pennies to create Java based mobile apps. You can outsource mobile app development to build Java android apps at the lowest cost.

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Changing Theme Of Android Studio

  • To change the theme of Android studio, Go to File> Settings. A new window will open and from there Go to Appearance & Behaviour> Appearance.
  • Now in the theme section, you can see the three options Darcula, High contrast, and IntelliJ and you can choose any one amongst them as per your taste.
  • Lets have a look at the Android Studio user interface after applying Darcula theme.

So finally we have covered up all the necessary details about how to use Android Studio, and if you still find something is missing, then please let us know through your comments.

Why Is Java Easy To Learn

Part 2 Android Studio Java program for android calculator

Java is easy to learn for a variety of reasons. Theres certainly no shortage of Java resources out there to help you learn the language, including websites, tutorials, books, and classes. Java is one of the most widely discussed, taught, and used programming languages on the planet. Its used for many different types of programming projects, no matter their scale, from web applications to desktop applications to mobile applications.

If youre coming from a traditional programming background like C or C++, youll find Java syntax quite similar. If youre not, then take comfort in knowing that youve chosen one of the easiest languages to learn. Youll be up and running in no time at all.

Finally, Java is one of the most human-readable languages out there, by which we mean that a person who knows nothing about programming can often look at some Java code and have at least an inkling what its doing. Consider the following example:

char character = 'a' if else 

If you simply read the code aloud, you can pretty much tell that this snippet of code is doing. Theres a single letter variable called character. If the character variable equals the letter a, then we do something method), otherwise we do something else method).

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Creating Your Android App

By now, you have done all the groundwork you have acquired the skills and tools required for making your first Android app using Java. It is time to let your creativity take center stage. Android Studio workspace will show your directory structure, an Android phone with the words Hello World on its virtual screen. Let your programming skills bring your app idea alive!

Is It Necessary For Developers To Learn Kotlin

Again, there are mixed opinions.

While it is not entirely necessary for developers to make the switch to Kotlin, theyre going to encounter the language eventually. If youre already familiar with Java, learning Kotlin will be simple. The language is poised to impact app development on a massive scale, so it doesnt hurt to learn the basics of the language. Additionally, growing with modern techniques and development styles will aid the growth of any developers skill set.

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Explore Width And Height Properties

Now that you have a new screen background color, you will use it to explore the effects of changing the width and height properties of views.

  • In fragment_first.xml, in the Component Tree, select the ConstraintLayout.
  • In the Attributes panel, find and expand the Layout section.
  • The layout_width and layout_height properties are both set to match_parent. The ConstraintLayout is the root view of this Fragment, so the “parent” layout size is effectively the size of your screen.

    Tip: All views must have layout_width and layout_height properties.

  • Notice that the entire background of the screen uses the screenBackground color.
  • Select textview_first. Currently the layout width and height are wrap_content, which tells the view to be just big enough to enclose its content
  • Change both the layout width and layout height to match_constraint, which tells the view to be as big as whatever it’s constrained to.
  • The width and height show 0dp, and the text moves to the upper left, while the TextView expands to match the ConstraintLayout except for the button. The button and the text view are at the same level in the view hierarchy inside the constraint layout, so they share space.

  • Explore what happens if the width is match_constraint and the height is wrap_content and vice versa. You can also change the width and height of the button_first.
  • Set both the width and height of the TextView and the Button back to wrap_content.
  • The Requirement To Get Started With Android Messages On Your Computer

    #3 Android Studio Overview – Android Development Tutorial 2020 in Java

    To get started with Android Messages on your computer, you should fulfill the following requirements:

    On your phone:

    • You need to use the latest version of the Android Messages app.
    • Internet connection .
    • Android device running on OS version 5.0 or higher. Here are the steps to check what version of Android you have.

    On your computer:

    • You should have any one of these web browsers: Google Chrome, Firefox, Microsoft Edge, or Safari. It is currently not available on Internet Explorer .
    • An internet connection .

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    Update The Textview To Display The Header

  • In fragment_second.xml, select textview_second, which currently has the text “Hello second fragment. Arg: %1$s” in the hello_second_fragment string resource.
  • If android:text isn’t set, set it to the hello_second_fragment string resource.
  • Change the id to textview_header in the Attributes panel.
  • Set the width to match_constraint, but set the height to wrap_content, so the height will change as needed to match the height of the content.
  • Set top, left and right margins to 24dp. Left and right margins may also be referred to as “start” and “end” to support localization for right to left languages.
  • Remove any bottom constraint.
  • In strings.xml, change hello_second_fragment to “Here is a random number between 0 and %d.”
  • Use Refactor > Rename… to change the name of hello_second_fragment to random_heading.
  • Here is the XML code for the TextView that displays the heading:

    Update The Appearance Of The Textview

  • Remove the background color of the TextView, either by clearing the value in the Attributes panel or by removing the android:background attribute from the XML code.
  • When you remove the background, the view background becomes transparent. 2. Increase the text size of the TextView to 72sp.

  • Change the font-family of the TextView to sans-serif .
  • Add an app:layout_constraintVertical_bias property to the TextView, to bias the position of the view upwards a little so that it is more evenly spaced vertically in the screen. Feel free to adjust the value of this constraint as you like.
  • app:layout_constraintVertical_bias="0.3"
  • You can also set the vertical bias using the Constraint Widget. Click and drag the number 50 that appears on the left side, and slide it upwards until it says 30.
  • Tip: Using the bias attribute instead of margins or padding results in a more pleasing layout on different screen sizes and orientations.

    • If a view is constrained to other views on both its top and bottom edges, use vertical bias to tweak its vertical position.
    • If a view is constrained on both its left and right edges, use horizontal bias to tweak its horizontal position.
  • Make sure the layout_width is wrap_content, and the horizontal bias is 50 .
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    Set Up The Android Studio Proxy

    Android Studio supports HTTP proxy settings so you can run Android Studio behinda firewall or secure network. To set the HTTP proxy settings in Android Studio:

  • From the menu bar, click File > Settings .
  • In the left pane, click Appearance & Behavior > System Settings > HTTPProxy. The HTTP Proxy page appears.
  • Select Auto-detect proxy settings to use an automatic proxy configurationURL for the proxy settings or Manual proxy configuration to enter each ofthe settings yourself. For a detailed explanation of these settings, see HTTP Proxy.
  • Click Apply or OK for your changes to take effect.
  • How To Set Java Sdk Path In Android Studio

    Steps to create a native Android plugin for Unity in Java using Android ...

      The Java SDK for Android is a sophisticated suite of tools for managing, monitoring, profiling, and debugging Java code written in Android Studio. But sometimes as software is unpredictable you might be caught in an error that Android Studio stopped compiling projects and says that it cant locate the 1.7.0_21 folder. Well, this is exactly what is referred to as a missing Java SDK Path.

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      Features Of Android Studio

      • It has a flexible Gradle-based build system.
      • It has a fast and feature-rich emulator for app testing.
      • Android Studio has a consolidated environment where we can develop for all Android devices.
      • Apply changes to the resource code of our running app without restarting the app.
      • Android Studio provides extensive testing tools and frameworks.
      • It supports C++ and NDK.
      • It provides build-in supports for Google Cloud Platform. It makes it easy to integrate Google Cloud Messaging and App Engine.

      Primary Constructor Vs Secondary Constructors

      Kotlin supports the specification of a “primary constructor” as part of the class definition itself, consisting of an argument list following the class name. This argument list supports an expanded syntax on Kotlin’s standard function argument lists, that enables declaration of class properties in the primary constructor, including visibility, extensibility and mutability attributes. Additionally, when defining a subclass, properties in super-interfaces and super-classes can be overridden in the primary constructor.

      // Example of class using primary constructor syntax// openclassPowerUser:User

      However, in cases where more than one constructor is needed for a class, a more general constructor can be used called secondary constructor syntax which closely resembles the constructor syntax used in most object-oriented languages like C++, C#, and Java.

      // Example of class using secondary constructor syntax// classMyButton:View// Constructor #2constructor:super}

      The Sealed classes and interfaces restrict the subclass hierarchies, meaning more control over the inheritance hierarchy.


      All the subclasses of the sealed class are defined at compile time. No new subclasses can be added to it after the compilation of the module having the sealed class.For example, a sealed class in a compiled jar file cannot be subclassed.


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      Keep Your Android Phone Power On

      The Android Messages on the computer can’t work separately from your phone. It would be best if you always turned on your phone while using Android Messages from a computer. If your phone’s battery dies or gets switched off for any reason, you won’t be able to access Android Messages on the web. And this will refuse you from sending any text messages from your computer.

      Can Android Studio Be Used To Run Standard Java Projects

      How to use Android Studio

      For those times when you want to isolate the Java and give it a quick test..

      Can you run non-Android Java projects in Android studio as in Eclipse?

      • 2Android studio is based upon intelliJ. So sure, it surely able to run “standard” java code. But why do you need it ?May 18 ’13 at 17:00
      • 1 BlackbeltMay 18 ’13 at 17:18
      • 1Is there a simple way to get this to work with Gradle yet? I keep crashing because it cannot see my gradle libraries at runtime.

      Tested on Android Studio 0.8.6 – 3.5

      Using this method you can have Java modules and Android modules in the same project and also have the ability to compile and run Java modules as stand alone Java projects.

    • Open your Android project in Android Studio. If you do not have one, create one.
    • Click File > New Module. Select Java Library and click Next.
    • Fill in the package name, etc and click Finish. You should now see a Java module inside your Android project.
    • Add your code to the Java module you’ve just created.
    • Click on the drop down to the left of the run button. Click Edit Configurations…
    • In the new window, click on the plus sign at the top left of the window and select Application
    • A new application configuration should appear, enter in the details such as your main class and classpath of your module.
    • Click OK.
    • Now if you click run, this should compile and run your Java module.

      NEW – How to enable Kotlin in your standalone project

      If you want to enable Kotlin inside your standalone project, do the following.

      Thanks buddies

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      Why Is Platform Independence Important

      With many programming languages, you need to use a compiler to reduce your code down into machine language that the device can understand. While this is well and good, different devices use different machine languages. This means that you might need to compile your applications for each different device or machine languagein other words, your code isnt very portable. This is not the case with Java. The Java compilers convert your code from human readable Java source files to something called bytecode in the Java world. These are interpreted by a Java Virtual Machine, which operates much like a physical CPU might operate on machine code, to actually execute the compiled code. Although it might seem like this is inefficient, much effort has been put into making this process very fast and efficient. These efforts have paid off in that Java performance in generally second only to C/C++ in common language performance comparisons.

      Android applications run in a special virtual machine called the Dalvik VM. While the details of this VM are unimportant to the average developer, it can be helpful to think of the Dalvik VM as a bubble in which your Android application runs, allowing you to not have to worry about whether the device is a Motorola Droid, an HTC Evo, or the latest toaster running Android. You dont care so long as the device is Dalvik VM friendlyand thats the device manufacturers job to implement, not yours.

      Launch New Android Project

      All the magic happens inside an Android Studio project. A project contains all the components you need to get your Android app idea off the ground, up and running. Your workspace, source code, assets, test code, and other related configurations everything is placed inside a project.

      Once you complete your development process, all project contents are packaged into an APK . Make sure you choose your project name wisely, as your package name takes the format:


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      Why Java For Android Application Development

      If you want to get started with application development, Google provides a Java API to get started and compiles your files into classes. Why did Android prefer Java for its development platform? There are multiple reasons such as Java is a commonly used language and many programmers know it, it can run on a virtual machine so no need to recompile for different phones, better security, many development tools available for Java, and Java is a known industry language with most phones compatible with it.

      Though Google provides the Java API, Android does not use JVM to execute class files. Rather, it uses Dalvik Virtual Machine . The class files are compiled into Dalvik Executable format, and bundled as Android Package along with other resources.

      With Java, if you are aware of object-oriented programming principles, creating applications for android will be much simpler than iOS app development.

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