Configuring and Importing a Flink Sample Project

Scenario

Flink provides sample projects for multiple scenarios, including Java and Scala sample projects to help you quickly learn Flink projects.

Methods to import Java and Scala projects are the same.

The following example describes how to import Java sample code. Figure 1 shows the operation process.

Figure 1 Procedure of importing a sample project

Procedure

Download the sample project to the local computer by referring to Obtaining the MRS Application Development Sample Project.
Copy the client installation package downloaded in Installing the Flink Client to the Windows server.
Decompress MRS_Flink_Client.tar on the Windows server to obtain the MRS_Flink_ClientConfig.tar. Decompress the MRS_Flink_ClientConfig.tar to obtain the MRS_Flink_ClientConfig folder.
Double-click the flink_install.bat script in the MRS_Flink_ClientConfig/Flink directory. After the installation is complete, the lib and examples folders are generated.
- The lib folder contains only the JAR files on which Flink depends. Find JAR files on which Kafka depends in the installation directory of the Kafka component on the server and add them.
- The examples folder contains the open source sample JAR file.
Before importing the sample project, configure JDK for IntelliJ IDEA.
1. Start IntelliJ IDEA and click Configure.
  Figure 2 Clicking Configure
2. Choose Project Defaults from the Configure drop-down list.
  Figure 3 Choosing Project Defaults
3. Choose Project Structure on the Project Defaults page.
  Figure 4 Project Defaults
4. On the Project Structure page, select SDKs and click the green plus sign to add the JDK.
  Figure 5 Adding the JDK
5. On the Select Home Directory for JDK page that is displayed, select the JDK directory and click OK.
  Figure 6 Selecting the JDK directory
6. After selecting the JDK, click OK to complete the configuration.
  Figure 7 Completing the JDK configuration
Import the Java sample project to IDEA.
1. Start the IntelliJ IDEA. On the Quick Start page, select Import Project.
  Alternatively, for the used IDEA tool, add the project directly from the IDEA home page. Choose File > Import project... to import a project.
  Figure 8 Importing the project (on the Quick Start page)
2. Select a path for storing the sample project to be imported and click OK.
  Figure 9 Select File or Directory to Import
3. Select Create project from existing sources and click Next.
  Figure 10 Create project from existing sources
4. Confirm the project location and project name and click Next.
  Figure 11 Import Project
5. Retain the default value of the root directory for the project to be imported and click Next.
6. Retain the default dependency library that is automatically recognized by IDEA and the suggested module structure and click Next.
7. Confirm the JDK used by the project and click Next.
  Figure 12 Selecting the project SDK
8. After the import is complete, click Finish. Then the imported sample project is displayed on the IDEA home page.
  Figure 13 Imported project
(Optional) If a Scala sample application is imported, install the Scala plug-in on the IntelliJ IDEA.
1. Choose Plugins from the Configure drop-down list.
  Figure 14 Plugins
2. On the Plugins page, choose Install plugin from disk.
  Figure 15 Choosing Install plugin from disk
3. On the Choose Plugin File page, select the Scala plugin file of the corresponding version and click OK.
  Figure 16 Choose Plugin File
4. On the Plugins page, click Apply to install the Scala plugin.
5. On the Platform and Plugin Updates page that is displayed, click Restart to make the configurations take effect.
  Figure 17 Platform and Plugin Updates
Import the dependency JAR file for the sample project.
1. On the IDEA home page, choose File > Project Structures... to go to the Project Structure page.
2. Select Libraries and click + to add the dependency package of Java.
  Figure 18 Add Java
3. On the Select Library Files page, select all JAR files in the lib directory, and click OK.
  Flink dependency package: Select all JAR files in the lib directory. Alternatively, select a minimum of corresponding JAR files based on various sample projects.
  
  If other MRS components are used in the sample code, obtain them from the installation directory of these MRS components.
  
  Figure 19 Select Library Files
  
  On the Choose Modules page, select all modules for the sample project. Then, click OK.
  
  Figure 20 Choose Modules
4. Click OK to complete the project library import.
(Optional) If a Scala sample application is imported, configure a language for the project.
1. On the IDEA home page, choose File > Project Structures... to go to the Project Structure page.
2. Choose Modules, right-click a project name, and choose Add > Scala.
  Figure 21 Selecting Scala
3. Wait until IDEA identifies the Scala SDK, choose the dependency JAR files on the Add Scala Support page, and then click OK.
  Figure 22 Add Scala Support
4. If IDEA fails to identify the Scala SDK, you need to create a Scala SDK.
  1. Click Create ....
    Figure 23 Clicking Create...
  2. On the Select JAR's for the new Scala SDK page, click Browse....
    Figure 24 Select JAR's for the new Scala SDK
  3. On the Scala SDK files page, select the scala sdk directory, and then click OK.
    Figure 25 Scala SDK files
5. Click OK.
  Figure 26 Configuration successful
Configure the text file encoding format of IDEA to prevent garbled characters.
1. On the IDEA home page, choose File > Settings....
  Figure 27 Choosing Settings
2. On the Settings page, unfold Editor, and choose File Encodings. Select UTF-8 from the IDE Encoding and Project Encoding drop-down lists on the right. Click Apply.
3. Click OK to complete the encoding settings.