Can Java be Used for Automation?

The java programming language is an open-source framework, this framework is used for creating and running automated tests. The java Automation technique deals with that code which can be used to control the execution of specific user interface operations in the java programming language. 

So we can clearly understand that java can be used for automation, so today in this article we will learn how we can use java for automation with the help of specific points and examples in this article.

Scope of the article

• In this article, we will learn how and why we should use the java language for automation testing.
• We will learn about the different techniques for automating a java application.
• We will learn about the main sources of errors that are decided to streamline or otherwise improve the three key areas.

Introduction

We know that java is widely used by us for many years and now there are many readily available frameworks, plugins, APIS, and libraries present there which support java for automation. The java virtual machine(JVM) is used to make the java language a platform-independent language. 

We can run the java program on any machine where the JVM is installed in the operating system. To make benefit from these functionalities we need to specify the type of application in java while launching the application modeler wizard. Java testing offers a more comprehensive package and it is a useful test case that helps to take care of every element of the application. This is why we use java for automation.

Now let us read about the different approaches which can be used for automation in java:

Different ways of automation in java:

Three ways can be used for automation in java. They are:

• We can use the robot class to automate in java
• We can use the reflection to launch the application
• We can inject our code into another application for java automation.

Now that we know that all these three processes are used for java automation, so let us see now learn about each of these methods in detail:

How we can use the robot class to automate in java

Since we know that robot is one of the classes which is provided by the Java programming language to simulate mouse click/keyboard events. We can use this in any class to automate not only Java but any application.

Lets us read more about the automation possible scenarios using the robot class technique in java:

• We know that the screen resolution is the same across all the desktops.
• In this process, each application opens with a fixed width and height or the application opens in maximized state.
• The user should not perform any other operation while the automation is running.

Now let us read about the advantages and disadvantages of this process:

Advantages

• This process performs a mouse click at the specified location.
• In this process, we can assume that the focus is already present in the required field.

Now let us read about the disadvantages of this process:

Disadvantages

• When the application is moved to the screen then this cannot method cannot be used.
• The user needs to wait till the operation is completed.
• Retrieving values from any field is not possible in this process.

Now the next process is:

Using Reflection

The reflection process in java is used to inspect and change the behavior of a program at the time of execution of the program. This is used to manipulate how the java applications are executed using the JVM. Using reflection API, we can inspect classes, constructors, modifiers, fields, methods, and interfaces at runtime. 

The Java programming language provides us with a feature called Reflection which allows us to modify the runtime behavior of a class or field or method at runtime. Hence we can say that reflection can be defined as a technique of inspecting and modifying the runtime behavior of an unknown object at run time. An object can either be a class or a field or a method.

Now let us read about the automation possible scenarios of this automation process:

How we can use reflection to automate java

We can run a simple command which is java –jar UIApplication.jar while running heavy and thick applications in java. With the reflection API in java, we can implement the reflection on the entities like the field, class, constructor, and modifier. The Applet applications with the help of a simple tag <Applet class=” my.applet.example.ClassName” width=”500” height==”300” /> can be automated. If the applet tag is generated using the JSP or if it is retrieved from the application server after a few steps then it becomes difficult.

Now let us read about the advantages and disadvantages of this method of automation:

Advantages of this process

• In this process background processing is possible.
• We do not need to depend on the screen resolution/position of the application on the screen.
• We can Retrieve values from specified objects in this process which were not possible in the robot class process.

Disadvantages of this process

• In this process, the applets cannot be automated.
• The jar files wrapped as exe cannot be automated using this process.
• In this process, the thick client apps with complex launching logic will be difficult to automate.

Now let us read about the third method and the last method of automation in java:

The process of injecting Code into a running java virtual machine:

This is one of the best-suited methods for automation in java. There are two approaches to injecting the code into the java virtual machine they are the Agentmain method and the remaining method. The class java.lang.instrument.Instrumentation can be used to inject code in running a java virtual machine.

Now let us read about them in detail:

We can use the main method:

The main method is a mechanism in java that is associated with java. lang.instrument package, which is used for the loading of agents that make the byte-code changes in Java programs and java a platform-independent language. The automation-related code is executed from the main method. These two run in the same java virtual machine so that automation code can get hold of UI objects easily.

Automation possible scenarios of this method

Before launching the app, we need an environment variable JAVA_TOOL_OPTIONS is required to set with value as –javaagent:”<PATH TO JAVAAGENT>”.

Advantages of this method

• We can click the mouse click for the specified object using this method.
• The jar files wrapped as exe can be automated using this process which was not possible using the reflection method.
• In this method, all the Java Network Launch Protocol (JNLP) Support applications can be automated.
• In this method all the applet applications can be automated which was not possible using the reflection method.
• In this method, two or more applets embedded in one HTML can also be automated.

Disadvantages of this method

• This method requires extra permission for the socket connection.
• This method also depends on the app which may require giving all permission as well.

Usage of the pre-defined environment variables for automation

To access this We will have to add the Java Agent along with the application and to do this, we need to pass the JVM parameter ‘-javaagent:<Java agent path>’. The environment variables do not work in a few scenarios, like if Java Network Launch Protocol (JNLP) Support applications itself has the JVM argument set, then this will be ignored.

Conclusion

• We can separate each test from every other test.
• We should avoid making irrational claims.
• The process of injecting code into a third-party application using java instrumentation is the best-suited approach for automating Java applications that we have read.
• We have read about the different processes of automating any kind of Java applications and in the process, we have identified and overcome the various hurdles faced in the path and lastly concluded that we can use java for automation.