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Developing Functions in Java (Using an IDEA Java Project)

Perform the following procedure to develop a Java function:

  1. 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 RunTime-1.1.3.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

  2. Create a function.

    1. 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
    2. Define the function handler in TriggerTests.java, as shown in Figure 5. 
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      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

    The example code contains multiple handler functions, which use different types of triggers.

  3. 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

  4. Log in to the FunctionGraph console, create a Java function, and upload the JAR file, as shown in Figure 10.

    Figure 10 Creating a function

  5. Test the function.

    1. Create a test event.

      Select timer-event-template from the Event Template drop-down list and click Save, as shown in Figure 11.

      Figure 11 Configuring a test event
    2. Click Test.

      The function execution result consists of three parts: function output (returned by callback), summary, and log (output by using the console.log or getLogger() method), as shown in Figure 12.

      Figure 12 Execution result