55f6c91cab
### What is this PR for?
Avoiding outdated checkstyle error.
To check format
`mvn validate`
To fix non-complying files
`mvn fmt:format`
### What type of PR is it?
[Improvement | Refactoring]
### Todos
* [x] - Adopt `fmt-maven-plugin`
### What is the Jira issue?
* https://issues.apache.org/jira/browse/ZEPPELIN-3740
### How should this be tested?
CI passs
### Screenshots (if appropriate)
### Questions:
* Does the licenses files need update? No
* Is there breaking changes for older versions? No
* Does this needs documentation? Yes for contributors
Author: Jongyoul Lee <jongyoul@gmail.com>
Closes #3158 from jongyoul/ZEPPELIN-3740 and squashes the following commits:
|
||
|---|---|---|
| .. | ||
| src | ||
| pom.xml | ||
| README.md | ||
Overview
Java interpreter for Apache Zeppelin
Architecture
Current interpreter implementation supports the static REPL. It compiles the code in memory, execute it and redirect the output to Zeppelin.
Technical overview
-
Upon starting an interpreter, an instance of
JavaCompileris created. -
When the user runs commands with java, the
JavaParsergo through the code to get a class that contains the main method. -
Then it replaces the class name with random class name to avoid overriding while compilation. It creates new out & err stream to get the data in new stream instead of the console, to redirect output to Zeppelin.
-
If there is any error during compilation, it can catch and redirect to Zeppelin.
-
JavaInterpreterUtilscontains useful methods to print out Java collections and leverage Zeppelin's built in visualization.