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https://github.com/apache/zeppelin
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55 lines
1.9 KiB
Markdown
55 lines
1.9 KiB
Markdown
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---
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layout: page
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title: Java interpreter in Apache Zeppelin
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description: Run Java code and any distributed java computation library by importing the dependencies in the interpreter configuration.
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group: interpreter
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---
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<!--
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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-->
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{% include JB/setup %}
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# Java interpreter for Apache Zeppelin
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<div id="toc"></div>
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## How to use
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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.
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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`.
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```java
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%java
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import java.util.HashMap;
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import java.util.Map;
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import org.apache.zeppelin.java.JavaInterpreterUtils;
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public class HelloWorld {
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public static void main(String[] args) {
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Map<String, Long> counts = new HashMap<>();
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counts.put("hello",4L);
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counts.put("world",5L);
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System.out.println(JavaInterpreterUtils.displayTableFromSimpleMap("Word","Count", counts));
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}
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}
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```
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