Developing Functions in Java (Using an IDEA Java Project)

Perform the following procedure to develop a Java function:

Create a function project.
1. Configure the IDEA and create a Java project named JavaTest, as shown in Figure 1.
  Figure 1 Creating a project
2. Add dependencies to the project.
  Download the Java SDK to a local development environment, and decompress the SDK package, as shown in Figure 2.
  
  Figure 2 Decompressing the downloaded SDK
3. Configure dependencies.
  Create a folder named lib in the project directory, copy the Runtime2.0.5.jar file and other required dependencies to the lib folder, and add the JAR files as the dependencies of the project, as shown in Figure 3.
  
  Figure 3 Configuring dependencies

Create a function.

Create a package named com.huawei.demo, and then create a class named TriggerTests under the package, as shown in Figure 4.
Figure 4 Creating the TriggerTests class

Define the function handler in TriggerTests.java, as shown in Figure 5.

       
        
          
          
            package com.huawei.demo;

import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Map;

import com.huawei.services.runtime.Context;
import com.huawei.services.runtime.entity.apig.APIGTriggerEvent;
import com.huawei.services.runtime.entity.apig.APIGTriggerResponse;
import com.huawei.services.runtime.entity.dis.DISTriggerEvent;
import com.huawei.services.runtime.entity.dms.DMSTriggerEvent;
import com.huawei.services.runtime.entity.lts.LTSTriggerEvent;
import com.huawei.services.runtime.entity.smn.SMNTriggerEvent;
import com.huawei.services.runtime.entity.timer.TimerTriggerEvent;

public class TriggerTests {
    public static void main(String args[]) {}
    public APIGTriggerResponse apigTest(APIGTriggerEvent event, Context context){
        System.out.println(event);
        Map<String, String> headers = new HashMap<String, String>();
        headers.put("Content-Type", "application/json");
        return new APIGTriggerResponse(200, headers, event.toString());
    }

    public String smnTest(SMNTriggerEvent event, Context context){
        System.out.println(event);
        return "ok";
    }

    public String dmsTest(DMSTriggerEvent event, Context context){
        System.out.println(event);
        return "ok";
    }

    public String timerTest(TimerTriggerEvent event, Context context){
        System.out.println(event);
        return "ok";
    }

    public String disTest(DISTriggerEvent event, Context context) throws UnsupportedEncodingException{
        System.out.println(event);
        System.out.println(event.getMessage().getRecords()[0].getRawData());
        return "ok";
    }

    public String ltsTest(LTSTriggerEvent event, Context context) throws UnsupportedEncodingException {
        System.out.println(event);
        event.getLts().getData();
        System.out.println("raw data: " + event.getLts().getRawData());
        return "ok";
    }
}

           

         

       
      

A common Java project needs to be compiled using artifacts, and a main function needs to be defined.

Figure 5 Defining the function handler

For details about the constraints for the APIG event source, see Base64 Decoding and Response Structure.

Pack the project file.
1. Choose File > Project Structure. The Project Structure page is displayed, as shown in Figure 6.
  Figure 6 Going to the Project Structure page
2. Choose Artifacts and click + to add artifacts, as shown in Figure 7.
  Figure 7 Adding artifacts
3. Add a main class, as shown in Figure 8.
  Figure 8 Adding a main class
4. Choose Build > Build Artifacts to compile the JAR file, as shown in Figure 9.
  Figure 9 Choosing Build Artifacts to compile the JAR file
Log in to the FunctionGraph console, create a Java function, and upload the JAR file, as shown in Figure 10.

Figure 10 Uploading a JAR file
Test the function.
1. Create a test event.
  Select timer-event-template from the Event Template drop-down list and click Create.
2. Click Test.
  The function execution result consists of three parts: function output (returned by callback), summary, and log (output by using the System.out.println() method).