Java converter for android

How to Create a Simple Currency Converter App in Android Studio

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I have been working on a number of projects as of late and today I wanted to share with you some of them.

This tutorial will take you through a step-by-step process on how to create a simple currency converter app in Android studio.

We shall be using Java and at the same time to convert this application to Kotlin (if time allows).

Java and Kotlin are now the most popular Android development languages, with the latter being the official programming language for making apps in Android Studio.

We assume all factors EW constant, you have Android Studio installed on your PC, and the environment has been properly set up.

As such, in this tutorial, we are going to use Android Studio for our simple currency converter Android application.

Simple Currency Converter Android App Example and How to Create It

Open Android Studio from Start Menu > All Programs or simply tap the icon on the desktop to get started.

Wait for a few minutes as Android Studio launches. This may take a while depending on the computer speed processor or RAM. You may need to wait until Gradle Sync is finished.

Once Android Studio has been fully launched, go to File > New and Create a new Project and name it Currency Converter App or anything you want.

Click Next, then select the Form Factors and minimum SDK. Just tick Phone and Tablet and select at least API 15: Android 4.0.3 (IceCreamSandwich). We are targeting this API because it powers at least 90% of all Android devices in the world.

You should always try to make Android applications compatible with the majority of the Android devices in the market.

Click Next and Add an empty Activity to our Project.

In Create a new empty Activity, simply continue with defaults and click Finish.

Go to res folder > Layout and select activity_main.xml. Click Text to add the following piece of XML code.

Relative Layout

In this tutorial, we shall use Relative Layout to align our currency converter app widgets. You can add Relative Layout to the activity_main.xml file by implementing the code snippet below.

Plain Text (Text View)

We need to add a Text View with the text «Enter Currency in dollars,» assuming we are doing a currency converter for converting dollars to euros.

You can implement this by adding the following code below to activity_main.xml file.

Edit Text View

This widget will allow a user to add a figure or currency that needs to be converted. You can also implement the Edit Text widget in activity_main.xml using the code snippet below.

Note: Text hint allows Edit Text widget to show sample information or give a hint; a user is required to add to this field or box.

Button Widget

You can now add the button widget that a user clicks and converts the figures in an Edit Text widget to another currency. Use the code snippet below to implement this.

Note: The on Click Method, convertToEuro , will be used in our Java code.

Image View

To make our application look nice, you may need to add some image widgets with an image placed below the button. Use the code snippet below to add this piece of code to your Simple Currency Converter App.

Note: You’ll have to download a sample image from Google. Copy and paste it in your drawable folder (drawable is also under res).

After that, everything is complete for our activity_main.xml file. We shall have something like the code below.

Activity_main.xml

Add Java Code Implementations in the MainActivity.java File

Head back to Java > com.example.currencyconverterApp and select MainActivity.

First, you’ll find the onCreate method already created for you in the Main Activity Java file. This is code snippet for the onCreate method.

@Override protected void onCreate(Bundle savedInstanceState)

We now need to implement our very own convertToEuro method that we added to the button in activity_main.xml, as shown below.

public void convertToEuro(View view)

1. In the int euro = 2000; bit of code, 2000 is just a variable you can change to any currency rate depending on the Currency Converter App you want to make.
2. The result/output will be displayed as a toast. You can as well show it on the Activity_main.xml interface as TextView by adding the code snippet below.

TextView textView = (TextView)findViewById(R.id.textview); textView.setText(Double.toString(result));

MainActivity.java

Add this code implementation in the Java file, MainActivity.

public class MainActivity extends AppCompatActivity < public void convertToEuro(View view)< EditText editText = (EditText) findViewById(R.id.edtText); int dollars = Integer.parseInt(editText.getText().toString()); int euro = 2000; double result = dollars * euro ; Toast.makeText(MainActivity.this, Double.toString(result), Toast.LENGTH_LONG).show(); >@Override protected void onCreate(Bundle savedInstanceState) < super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); >>

I hope this was helpful to all those who want to create a simple app in Android Studio. You can leave a comment in the section below if you any issues with the implementations.

Published at DZone with permission of Martin Tumusiime . See the original article here.

Opinions expressed by DZone contributors are their own.

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How to Convert Java to APK Online

Have you ever wanted to take a Java project and turn it into an Android app that you can install on your phone or tablet? If so, you are in luck today. Of course, it is possible to convert Java to APK online using a variety of tools and services.

In this article, we will walk you through the steps for converting Java to APK online. And this includes the tools and services you will need for the Java to APK conversion process and the process for uploading and converting your Java code or JAR file using an online Java to APK converter

Also, you will learn about some tips for troubleshooting common issues during the Java-to-Android app conversion process.

What Do We Mean by Convert Java to APK Online?

To convert Java to APK online simply means to use a web-based tool or service to transform a Java project or file into an Android Package (APK) file, which is the file format used to distribute and install Android apps.

This process involves taking the source code and resources of a Java project and compiling them into an APK file that you can install on an Android device.

Interestingly, there are a variety of online tools and services available for converting Java to APK, including J2ObjC, Jar2Apk, and Andromo.

These tools allow you to upload your Java code or JAR file and then follow a series of steps to generate an APK file that you can install on your Android device.

Why Should We Convert Java to APK Online?

There are several reasons why you might want to convert Java to APK online:

1. To Create an Android App from a Java Project

If you have a Java project that you want to turn into an Android app, converting Java to APK online is an easy and efficient way to do it.

Using a web-based tool or service, you can upload your Java code or JAR file and follow a series of steps to generate an APK file that you can install on your Android device.

2. To Decompile an Android App

If you want to understand how an Android app was built or how it functions, you can use a web-based tool to decompile the app’s APK file and view the underlying code and resources. This can be useful for personal use or education, as it allows you to examine the inner workings of an app.

3. To Modify an Android App

If you want to make changes to an Android app, you can use a web-based tool to decompile the app’s APK file, modify the source code and resources, and then recompile the APK file with your changes.

This can be a useful process for developers or users who want to customize an app or fix bugs.

4. To Save Time and Resources

Converting Java to APK online can save you time and resources compared to other methods, as you don’t need to download any software or set up a local development environment.

You can simply upload your Java code or JAR file to a web-based tool or service and follow the steps to generate an APK file.

Overall, converting Java to APK online is a convenient and efficient way to create, decompile, or modify Android apps, and it offers a range of benefits for developers and users alike.

Also, in fact, converting Java to APK online is a useful process for developers who want to create Android apps from existing Java projects or for users who want to examine the inner workings of an Android app by decompiling its APK file.

How to Convert Java to APK Online

Step 1: Choose a Tool or Service

There are several options for converting Java to APK online, including paid services and free tools. Some of the most popular options include:

J2ObjC: This is a free, open-source tool developed by Google that converts Java code to Objective-C for use on iOS devices. It can also be used to convert Java code to C++, which can then be compiled into an APK file using the Android NDK (Native Development Kit).

Jar2Apk: This is a free online tool that converts Java JAR files (a type of archive file used to package Java code) into APK files. It’s easy to use and requires no downloads, but it may not work with all Java code.

Andromo: This is a paid service that allows you to create Android apps from a variety of sources, including Java code. It offers a wide range of features and customization options, but it comes at a cost.

There are also other options available, such as the Android Studio IDE (Integrated Development Environment) and the Eclipse IDE, which allow you to write and debug Java code directly on your computer and then build and deploy it as an APK file.

Step 2: Prepare Your Java Code

Before you can convert your Java code to APK, you’ll need to make sure it’s in a format that’s compatible with the tool or service you’ve chosen. If you’re using J2ObjC or Jar2Apk, you’ll need to make sure your code is in a JAR file.

Also, if you’re using Andromo or an IDE like Android Studio, you’ll need to make sure your code is organized into a project with the appropriate file structure and dependencies.

Step 3: Upload Your Java Code

Once your Java code is prepared, you’ll need to upload it to the tool or service you’ve chosen. If you’re using J2ObjC or Jar2Apk, you’ll need to upload the JAR file.

Also, if you’re using Andromo or an IDE like Android Studio, you’ll need to either import the project or create a new project and then import your Java code.

Step 4: Convert Your Java Code

Once your Java code is uploaded, the tool or service will begin the process of converting it to APK.

If you’re using J2ObjC, the tool will first convert your Java code to Objective-C, and then you’ll need to use the Android NDK to compile it into an APK file.

Additionally, if you’re using Jar2Apk, the tool will automatically generate an APK file for you. If you’re using Andromo or an IDE like Android Studio, you’ll be able to build and deploy the APK file directly from the tool.

Step 5: Test Your APK File

Once the conversion process is complete, you’ll have an APK file that you can install on your Android device.

However, before you do, it’s a good idea to test the APK file to make sure it’s working correctly. You can do this by installing the APK file on an emulator.

Summary

In conclusion, converting Java to APK online is a straightforward process that allows you to turn your Java projects into Android apps that you can install on your phone or tablet.

There are a variety of online tools and services available for this purpose, including J2ObjC, Jar2Apk, and Andromo. The process involves uploading your Java code or JAR file to the tool or service and then following the steps for the Java to APK online conversion process.

Once the conversion is complete, you’ll have an APK file that you can install on your Android device.

Whether you’re looking to convert Java to APK for personal use or for professional development, there are plenty of online resources available to help you get started.

So, converting Java to APK online is an easy and efficient way to turn your Java projects into Android apps.

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Show Java 3.0.6

Декомпилятор apk для андроид, программа, главной функцией которой является преобразование готовых к установке apk к исходному виду проекта. Данная программа будет полезна программистам в процессе поиска решений по реализации той или иной фичи, создании модифицированных версий приложения, переводчикам в особо сложных ситуациях, когда куски текстов лежат вперемешку с кодом.

• Быстрота (обычные приложения разбирает на раз, а на более мощные, типа LP и AIDE корячится по 1.5-2.5 часа)
• Простота

Из минусов данной программы могу отметить:

• Декомпиляция больших/сложных/защищённых приложений зачастую проходит с ошибками и занимает гораздо больше времени
• В некоторых случаях полученные файлы имеют вид aaa.java>…

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