How to compile, package, and deploy code to Function Compute in a Java runtime - Function Compute

This topic describes how to compile a program in a Java runtime by using Maven or Serverless Devs and package the program as a ZIP or JAR file. After the code is compiled and packaged, you can upload the code package in the Function Compute console or by using Serverless Devs.

Dependency libraries of a Java runtime

To create and deploy a code package, you must compile and package the function code and dependency libraries together as a ZIP file or a JAR file.

Function Compute provides the following dependency libraries for a Java runtime:

com.aliyun:fc-java-core: defines information such as the handler interface and the context object used in a request handler.
com.aliyun:fc-java-events: provides the event types of common event sources.

You can use the Maven central repository to obtain the preceding dependencies. After you obtain the preceding dependency libraries, add them to the pom.xml file. The following sample code provides an example:

<!-- https://mvnrepository.com/artifact/com.aliyun.fc.runtime/fc-java-core -->
<dependency>
    <groupId>com.aliyun.fc.runtime</groupId>
    <artifactId>fc-java-core</artifactId>
    <version>1.4.1</version>
</dependency>

<!-- https://mvnrepository.com/artifact/com.aliyun.fc.runtime/fc-java-event -->
<dependency>
    <groupId>com.aliyun.fc.runtime</groupId>
    <artifactId>fc-java-event</artifactId>
    <version>1.2.0</version>
</dependency>

Note

If the dependency package is too large, you can package the dependencies into a layer to reduce the size of the code package. For more information, see Create a custom layer.

Compile and deploy code packages by using Maven

Before you start

Java and Maven are installed. For more information about Java, visit the Java official website. For more information about Maven, see Installing Apache Maven.

Procedure

Create a Java project. The following sample code provides the path of the App.java file:

src/main/java/example/App.java

Add the following sample code to the App.java file: For the detailed sample code, see Event handlers, HTTP handlers, or Context.

package example;

import com.aliyun.fc.runtime.Context;
import com.aliyun.fc.runtime.StreamRequestHandler;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class App implements StreamRequestHandler {

    @Override
    public void handleRequest(InputStream inputStream, OutputStream outputStream, Context context) throws IOException {
        outputStream.write(new String("hello world").getBytes());
    }
}

In the pom.xml file, configure build. Sample code:

<build>
        <plugins>
              <plugin>
                  <groupId>org.apache.maven.plugins</groupId>
                  <artifactId>maven-shade-plugin</artifactId>
                  <version>3.2.1</version>
                  <executions>
                    <execution>
                      <phase>package</phase>
                      <goals>
                        <goal>shade</goal>
                      </goals>
                      <configuration>
                        <filters>
                          <filter>
                            <artifact>*:*</artifact>
                            <excludes>
                              <exclude>META-INF/*.SF</exclude>
                              <exclude>META-INF/*.DSA</exclude>
                              <exclude>META-INF/*.RSA</exclude>
                            </excludes>
                          </filter>
                        </filters>
                      </configuration>
                    </execution>
                  </executions>
              </plugin>
        </plugins>
</build>

Note

You can use Apache Maven Shade or Apache Maven Assembly. The preceding example uses Apache Maven Shade as an example.

Expand to see the complete example pom.xml file

<project xmlns="http://maven.apache.org/POM/4.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>example</groupId>
  <artifactId>HelloFCJava</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>HelloFCJava</name>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>com.aliyun.fc.runtime</groupId>
      <artifactId>fc-java-core</artifactId>
      <version>1.4.1</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-shade-plugin</artifactId>
          <version>3.2.1</version>
          <executions>
            <execution>
              <phase>package</phase>
              <goals>
                <goal>shade</goal>
              </goals>
              <configuration>
                <filters>
                  <filter>
                    <artifact>*:*</artifact>
                    <excludes>
                      <exclude>META-INF/*.SF</exclude>
                      <exclude>META-INF/*.DSA</exclude>
                      <exclude>META-INF/*.RSA</exclude>
                    </excludes>
                  </filter>
                </filters>
              </configuration>
            </execution>
          </executions>
        </plugin>
    </plugins>
  </build>

  <properties>
    <maven.compiler.target>1.8</maven.compiler.target>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.test.skip>true</maven.test.skip>
  </properties>
</project>

Open the CLI, switch to the root directory of the project, and then run the mvn clean package command to perform packaging.

Sample code:

[INFO] Scanning for projects...
 ...  ....   ....
[INFO] --------------------------< example:example >---------------------------
[INFO] Building java-example 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
 ...  ....   ....
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  11.681 s
[INFO] Finished at: 2020-03-26T15:55:05+08:00
[INFO] ------------------------------------------------------------------------

If the compilation fails, modify the code based on the error message.
If the compilation is successful, the compiled JAR file is located in the target directory in the project folder and is named HelloFCJava-1.0-SNAPSHOT.jar according to the artifactId and version fields in pom.xml.
Important For macOS and Linux operating systems, make sure that the code file is readable and executable before compression.

Log on to the Function Compute console and upload the code package.
On the Configurations tab, check the value of Handler. A handler must follow the [Package Name].[Class Name]::[Method Name] format. For example, if the package name is example, the class name is App, and the method name is handleRequest, the handler can be configured as example.App::handleRequest. You can click Modify to modify the handler if it is not valid.
On the Code tab, click Test Function to test the function.

Compile and deploy code packages by using Serverless Devs

Before you start

Procedure

Run the following command to initialize the project:
```
s init devsapp/start-fc-event-java8 -d start-fc-event-java8
```
- s init devsapp/start-fc-event-java8: initializes the project based on the event handler template.
- -d start-fc-event-java8: outputs the project file to the specified directory.
After you run the command, select the region, service name, and function name, and configure the key as prompted.
Note
You can also run the s init command to select a template as prompted.
Run the following command to go to the project directory:
```
cd start-fc-event-java8
```

Run the following command to deploy the project:

s deploy

When you run this command, the pre-deploy command is run first. When the pre-deploy command is run, the mvn package command is used to perform compilation and packaging. The code package is uploaded and deployed after that. Sample command output:

[2022-04-07 12:00:09] [INFO] [S-CORE] - Start the pre-action
[2022-04-07 12:00:09] [INFO] [S-CORE] - Action: mvn package
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------< example:HelloFCJava >-------------------------
[INFO] Building HelloFCJava 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
......
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  3.617 s
[INFO] Finished at: 2022-04-07T20:00:14+08:00
[INFO] ------------------------------------------------------------------------
[2022-04-07 12:00:14] [INFO] [S-CORE] - End the pre-action

 Checking Service, Function (0.64s)
 Creating Service, Function (0.71s)

Tips for next step
======================
* Display information of the deployed resource: s info
* Display metrics: s metrics
* Display logs: s logs
* Invoke remote function: s invoke
* Remove Service: s remove service
* Remove Function: s remove function
* Remove Trigger: s remove trigger
* Remove CustomDomain: s remove domain



helloworld:
  region:   cn-hangzhou
  service:
    name: hello-world-service
  function:
    name:       start-fc-event-java8
    runtime:    java8
    handler:    example.App::handleRequest
    memorySize: 128
    timeout:    60

Run the s invoke command to perform testing.

Sample command output:

➜ start-fc-event-java8 s invoke
========= FC invoke Logs begin =========
FC Initialize Start RequestId: b246c3bf-06bc-49e5-92b8-xxxxxxxx
FC Initialize End RequestId: b246c3bf-06bc-49e5-92b8-xxxxxxxx
FC Invoke Start RequestId: b246c3bf-06bc-49e5-92b8-xxxxxxxx
FC Invoke End RequestId: b246c3bf-06bc-49e5-92b8-xxxxxxxx

Duration: 7.27 ms, Billed Duration: 8 ms, Memory Size: 128 MB, Max Memory Used: 65.75 MB
========= FC invoke Logs end =========

FC Invoke Result:
hello world



End of method: invoke