Java

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Available in Classic and VPC

This section describes how to create and use Java actions in a variety of ways, and includes application examples.

Create action

Creating Java actions is similar to creating JavaScript and Swift actions.

Note

To compile and test actions, JDK 8must be set up in your local environment.

A Java action is a Java program with a main method. The method must be defined in the following format:

public static com.google.gson.JsonObject main(com.google.gson.JsonObject);

Considering this requirement, here is an example of creating a Java action:

  1. Create a source code file named Hello.java.

    import com.google.gson.JsonObject;
    
    public class Hello {
        public static JsonObject main(JsonObject args) {
            String name = "World";
            String place = "Naver";
            if (args.has("name"))
                name = args.getAsJsonPrimitive("name").getAsString();
            if (args.has("place"))
                place = args.getAsJsonPrimitive("place").getAsString();
    
            JsonObject response = new JsonObject();
            response.addProperty("payload", "Hello, " + name + " in " + place + "!");
            return response;
        }
    }
    
  2. Use the command to compile Hello.java into a JAR file named hello.jar.

    $ javac Hello.java
    
    $ jar cvf hello.jar Hello.class
    
  3. Upload the generated hello.jar file to create an action named helloJava.

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  • Set main class: Hello class

If the class is not in the default package, you can use the Java fully-qualified class name (FQCN) including the package, such as com.example.MyMain.

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If you want to change the method name of the Java action, you can create an action by specifying a method name like methodName.
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Caution

When compiling Java files, google-gsonmust be included in the Java CLASSPATH.