zeppelin/docs/interpreter/java.md

layout	title	description	group
page	Java interpreter in Apache Zeppelin	Run Java code and any distributed java computation library by importing the dependencies in the interpreter configuration.	interpreter

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Java interpreter for Apache Zeppelin

How to use

Basically, you can write normal java code. You should write the main method inside a class because the interpreter invoke this main to execute the code. Unlike Zeppelin normal pattern, each paragraph is considered as a separate job, there isn't any relation to any other paragraph. For example, a variable defined in one paragraph cannot be used in another one as each paragraph is a self contained java main class that is executed and the output returned to Zeppelin.

The following is a demonstration of a word count example with data represented as a java Map and displayed leveraging Zeppelin's built in visualization using the utility method JavaInterpreterUtils.displayTableFromSimpleMap.

%java
import java.util.HashMap;
import java.util.Map;
import org.apache.zeppelin.java.JavaInterpreterUtils;

public class HelloWorld {

    public static void main(String[] args) {
    
        Map<String, Long> counts = new HashMap<>();
        counts.put("hello",4L);
        counts.put("world",5L);

        System.out.println(JavaInterpreterUtils.displayTableFromSimpleMap("Word","Count", counts));
        
    }

}