Intellij Idea 简明教程

Integration with useful tools like compiler, debugger, version control system, build tools, various frameworks, application profilers and so on.

Supports code navigation, code completion, code refactoring and code generation features which boosts development process.

Supports unit testing, integration testing and code coverage via plug-ins.

Provides rich set of plug-ins to enhance IDE functionality further.

Editor-centric environment − Quick pop-ups help in checking additional information without leaving the current context.

Shortcuts for everything − IntelliJ IDEA has keyboard shortcuts for nearly everything, including rapid selection and switching between tool windows and many more.

Inline debugger − Inline debugger allows you to debug application in IDE itself. It makes the development and debugging process seamless.

Version control − IntelliJ supports most of the popular version control system like Git, Subversion, Mercurial, CVS, Perforce, and TFS.

Build tools − IntelliJ supports Java and other build tools like Maven, Gradle, Ant, Gant, SBT, NPM, Webpack, Grunt, and Gulp.

Test runner and code coverage − IntelliJ IDEA lets you perform unit testing with ease. The IDE includes test runners and coverage tools for major test frameworks, including JUnit, TestNG, Spock, Cucumber, ScalaTest, spec2, and Karma.

Decompiler − IntelliJ comes with a built-in decompiler for Java classes. When you want to take a look inside a library that you do not have the source code for, you can do it without using any third-party plug-ins.

Terminal − IntelliJ provides built-in terminal. Depending on your platform, you can work with the command line prompt, like PowerShell or Bash.

Database tools − IntelliJ provides database tools, which allow you to connect to live databases; run queries; browse and update data; and even manage your schemas in a visual interface from IDE itself.

Application server − IntelliJ supports major application servers: Tomcat, JBoss, WebSphere, WebLogic, Glassfish, and many others. You can deploy your artifacts onto application servers and debug the deployed applications in IDE itself.

Docker support − Via a separate plug-in, IntelliJ provides a dedicated tool window that lets you connect to locally running Docker machines.

On the Welcome screen, click on ‘configure’

Select ‘project defaults’ from the drop-down list

Select the ‘project structure’ option

Select the ‘SDKs’ option from the ‘platform settings’ menu.

Click on the ‘plus’ icon and select the ‘JDK’ option.

Select JDK’s home directory and follow the on-screen instructions.

Launch IntelliJ.

Go to File → New → Project menu.

Select the Java project and appropriate SDK and click on the Next button.

If you want to create a Java class with the main method, then select Create Project from the template checkbox.

Select the command line app from the dialog box shown below and continue.

Enter the project name and the directory location.

Click on the Finish button.

Go to the project perspective.

Right-click on Project, select the New→Module option.

The new module window will be similar to the new project. Select the Java option and appropriate SDK and click on the Next button.

Enter the module name.

Click on the Finish button.

Go to the Project perspective.

Expand Project and select the src directory from the module.

Right click on it; select the New→Java Class option.

Enter the class name in the dialog-box and click on the OK button.

It will open the Editor window with the class declaration.

Let us write a simple code, which will print a message on the console. Enter the following code in the Editor window −

Go to the Run menu and select the Run option.

Select the Class name and click on Run.

If there are no compilation errors, then it will show output at the bottom of the window.

Go to File → Project structure.

Select modules and click on plus icon.

It will show the option to import module.

Sources − By assigning this category to folder, we instruct IntelliJ that this and its subfolder contain java source code and it should be compiled as part of the compilation process.

Tests − By assigning this category to folder, we instruct IntelliJ that it is the location for unit tests. This folder can access classes from the Sources folder.

Resources − It represents various resource files used in project, for instance, images, XML and properties files. During the compilation process, contents of this folder is copied as is to the output folder.

Excluded − Contents from the excluded folder will not be indexed by IntelliJ. This means that IntelliJ will not provide the code completion suggestion and other hints. For example, the output directory and the target directory are excluded by default.

Test resources − This is similar to the resources and used for unit tests.

Global level − Shared by all projects.

Project level − Shared by all the modules of project.

Module level − Shared by the classes of those modules.

Import it from existing source

Import it from the build model.

Navigating to File → New → Project from the existing source.

Select directory of the existing project, Maven’s pom.xml or Gradle’s build script.

Click on the OK button.

Related settings getting stored in a single file makes it easier to manage in directory-based project format.

If folder contains the idea subfolder then IntelliJ recognizes that project. Because of this, you don’t have select the ipr project explicitly.

Directory-based project format breaks settings into multiple files hence it is easier to select particular type of setting to store in version control system.

Select Employee word

Go to Refactor → Rename and rename it with Person.

Go to Refactor → Find and Replace Code Duplicates.

Select refactor scope and follow on-screen steps to complete action.

Go to Refactor → Copy, it will open the dialog box.

Enter new name and destination package.

Click on the OK button and it will do the needful.

Go to, Refactor → Move.

A new window will appear.

Select one of the options according to your choice and click on Refactor.

Select the sayHello() method.

Right-click on it and select the Refactor → Safe Delete option.

As the sayHello() method is being used it will show an error as in the following screenshot −

Select method.

Right-click on it and select the Refactor → Change signature action

A new window will appear wherein you can perform the above actions.

At the bottom of the window, it shows the preview of new signature.

Select the “String” data type.

Right-click on it and select Refactor → Type migration.

Enter the required data type in the given text box.

Choose scope and click on the Refactor button.

Create a Java class.

Right-click on it and select the Run option.

After the first Run, temporary configuration is added to the run menu.

Navigate to the Run → Edit Configuration.

Click on the Plus button to add new configuration.

Select Application from the dropdown list.

It will create un-named configuration.

Configure it according to your requirements and click on the OK button.

This saved configuration will be accessible from the Run menu along with other configurations.

Navigate to the Run → Edit Configuration.

Select configuration from the left pane and click on the Share checkbox.

It will store configuration on disk.

Select configuration from the Run menu.

Run the project as shown in the following screenshot −

Navigate to File → Project.

Select Maven option and click on Next button.

In the new project window enter tutorialspoint.com as GroupId and HelloWorld as ArtifactId.

In the New window, it will open the pom.xml file.

We need to add properties to this file; the final pom.xml file should look like this −

Navigate to the src/main/java directory.

Right click on it and select New → Java Class.

Navigate to Run → Edit Configuration.

Click on the green plus icon and select the Maven option from the dropdown menu.

Enter the project name as Maven-Package.

Provide package as the command line.

Click on the OK button.

Navigate to Run and select the Maven-Package option.

It will start building package. Upon successful building of the package, you will see the following result −

Navigate to File → Project and select Gradle.

Click on the Next button.

In the new project window, enter tutorialspoint as GroupId and HelloWorld as ArtifactId.

Click on the Next button, verify the project details and click on the Finish button.

Follow the on-screen instructions to complete the process.

Open the buildl.gradle file and write Hello task as shown in the above screenshot.

To compile this task, navigate to the Run → Build-Gradle option.

Select the Navigate → Test option.

A dialog box will appear wherein, you have to select Create New Test.

Follow the on-screen instructions to continue −

Provide the details about the test like testing library, class details, setUp, tearDown methods and so on.

Click on the OK button to continue.

A test class will be created. Initially it may fail to resolve some symbols. Navigate the cursor to the error line, it will show the hint symbol.

Select the appropriate option from the dropdown menu. We have selected the Add library ‘junit.jar!’ to classpath option −

Select unit test class from the Editor window.

Navigate to the Run menu and select the Run option.

The following result will be generated

Right-click on the red circle symbol.

Select the More options.

To remove breakpoint just click on same symbol.

Navigate to the Run menu.

Select the Debug option.

Go to run

Select smart step into.

Select the child function to go.

Start application in debugger

Navigate to Run→Evaluate expression.

Enter expression. In the example given below, the current value of variable ‘i’ is 0; hence, expression ‘i > 100’ will evaluate to false

Download it from here.

Extract the zip file.

Navigate to etc/visualvm.conf file and add the following line in this file −

If your JDK is installed in the C:\Program Files\Java\jdk-9.0.1 directory then it should look like this −

Double-click on the visualvm.exe file.

Select the application from left pane.

Select the monitor tab.

Navigate to View → Tool Windows → Database.

Click on the green plus icon and select Data Source → MySQL.

Enter the host address and click on the Test Connection button.

If everything goes well then it’ll show Successful as shown in above image.

Click on OK button to save connection.

Right-click on the database pane and select schema.

Select the New → Table option

A new window will appear. Define the table with columns, types and so on.

Click on the Execute button

Click on the Execute button

Select table from the database pane.

It will open table in the new window.

Click on the plus icon to insert new row.

Click on the Submit button to make the changes permanent.

Navigate to File → New → Project from Existing Sources

Select your NetBeans project directory.

When the Import Project wizard opens, select the Create project from existing sources option.

Follow the on-screen instructions to continue.

Navigate to File → New → Project from Existing Sources.

Select your NetBeans project directory.

When the Import Project wizard opens, select the Create project from existing sources option.

Follow the on-screen instructions to continue.