Compilation and deployment of code packages - Programming Languages| Alibaba Cloud Documentation Center

This topic describes how to compile a program in the Java runtime environment (Maven or Serverless Devs) and package it as a ZIP or JAR package. After the compilation and packaging are complete, you can upload the code package in the Function Compute console or by using the Serverless Devs tool.

Java run time dependency library

To create a deployment code package, compile and package the function code and dependency libraries together as a ZIP package or JAR package.

Function Compute Platform provides the following dependency libraries for Java run time:

com.aliyun:fc-java-core: Defines information such as the handler interface and context object used in the 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. Get the above dependency libraries and add them to your pom.xml file as follows:

<!-- 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 the layer to reduce the code package size. For more information, see Use layers in functions.

Compile and deploy using Maven

Prerequisites

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

Procedure

Create a Java project that has the following directory structure:
```
src/main/java/example/App.java  
```
Enter the sample code in the App.java file. For more information about the sample code, see Event handlers, HTTP handlers, or Context object.

Create a pom.xml file under the project root directory and configure the build in the pom.xml file. Example:

<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 plug-ins or Apache Maven Assembly plug-ins. The preceding example uses only Apache Maven Shade plug-ins.

Open a command line window, switch to the root directory of the project, and then run the mvn clean package command to package.
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 message shows that compilation failed, modify the code based on the error message.
- If the compilation succeeds, the compiled JAR package is located in the target directory in the project folder and named java-example-1.0-SNAPSHOT.jar based on the artifactId and version fields in the pom.xml.
  
  Notice 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, upload the code package, and then click Test Function on the Function Code tab to test the function.

Compile and deploy using Serverless Devs

Prerequisites

Install Serverless Devs
Configure Serverless Devs
Java Development Kit (JDK) is installed. For more information, visit the AdoptOpenJDK official website.
Maven is installed. For more information, visit the Apache Maven official website.

Procedure

Run the following command to initialize a project:
```
s init devsapp/start-fc-event-java8 -d start-fc-event-java8
```
- s init devsapp/start-fc-event-java8: indicates that the project is initialized based on the HTTP request handler template.
- -d start-fc-event-java8: indicates that the project file is output to the specified directory.
After you run the command, select the region, service name, function name, and key configuration as prompted.

Note You can also execute the s init 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

Executing this command will first execute the pre-deploy, pre-deploy will execute the mvn package compilation and packaging, and then upload the deployment code package. The following code provides a sample 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 the test.

The following code provides a sample 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