JDK download

The version at the time of writing was 8u121. Download the latest version of the JDK from here. Click "Accept License Agreement" and download the one that suits your environment.

JDK installation

Proceed with the installation. This area is omitted. Make a note of only the installation destination, as it will be required for the work through the next path. Reference: C: \ Program Files \ Java \ jdk1.8.0_121 \ bin

Pass the path to the JDK

After installing the JDK, add the environment variable Path.

Add environment variable

Invoke the "System" screen.

Call the "System Properties" screen from "Detailed System Settings". Click "Environment Variables" at the bottom of the "Detailed Settings" tab.

When the "Environment Variables" screen opens, select "Path" in "System Variables" at the bottom of the screen. After selecting, click "Edit".

Enter; at the end of "Variable value" and copy and paste the path to the JDK that you wrote down earlier. When there are multiple variables, multiple variable values can be set by separating them with ";". Refer to this area.

Check Path

From the command prompt

java -verison

Enter. If the version is displayed, there is no problem. If something goes through but I'm throwing an error, I restarted it for the time being (experience story).

Create test class

Try creating a project from IntelliJ again.

JDK selection

Create a project from "Create New Project" as usual. Select "Java" and select "JDK" from "New" on the right side of "Project SDK".

Select the local JDK path you just installed and click OK.

The screen will return to the original screen, so select the JDK you set earlier from the list box. After selecting, click the "Next" button.

Creating a project

Click "Next" without playing with it.

Enter the project name and click "Next".

Creating a test class

Right-click "src" in the project and select "New"-> "Java Class".

Write a class (calc) appropriately.

public class calc {
    public int sum(int x, int y)
    {
        return x + y;
    }
}

Creating a test directory

Right-click on the project → select "New" → "Directory".

Enter the directory name.

Select "Files"-> "Project Structure".

Select "Modules" from the left menu, right-click on the Tests created earlier, and select "Tests".

Creating a test class

Generate a test class

Right-click on the created Class "calc" source code. Select "Go To" → "Test".

Select "Create New Test ...".

JUnit 4 selection

Select JUnit 4 from "Testing library". Check "startUp / @ Before" and "tearDown / After". Also check the functions in Member. Click the "Fix" button next to "JUnit 4 library not found in the module".

A window will be displayed, so check "Use'JUnit4' ..." and click "OK".

Try to test

Write a red test

Write the test on the newly generated module.

import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public class calcTest{
    @Test
    public void sum() throws Exeption {
        calc obj = new calc();
        assertEquals(1, 1 + 1);
    }
}

Pass the test in red

Select the upper tab "Run"-> "Run"-> "calcTest" to execute. Alternatively, use the shortcut key "Alt + Shift + F10" to execute.

Pass the test in green

Rewrite the code so that it passes on the green and execute it.

Cooperation with GitHub

The author was exhausted around here. We will quietly borrow the wisdom of our predecessors. As a matter of fact, I haven't really understood the feeling of Git yet, so that's a topic for the future.

• Setting memo when linking IntelliJ IDEA and GitHub
• How to use Git and GitHub with IntelliJ IDEA
• Use GitHub from IntelliJ idea
• JUnit toddler on IntelliJ Idea

IntelliJ editor settings

• IntelliJ IDEA initial settings (mainly editor)

Impressions

Aye! Integrated development environment Yatter! … But to be honest, I can't deny the feeling that it is still being used for its functions. It will take a long time to get used to it because it is multifunctional. In the first place, getting used to Java coding itself is one of the challenges ... I wish I could make something interesting with Java as well as getting used to it.