Example Custom EL Function for StreamSets Data Collector

DomainNameEL.java

/**
 * Copyright 2017 StreamSets Inc.
 *
 * Licensed under the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.streamsets.el.example;

import com.google.common.net.InetAddresses;
import com.streamsets.pipeline.api.ElFunction;
import com.streamsets.pipeline.api.ElParam;
import com.streamsets.pipeline.api.ElDef;

@ElDef
public class DomainNameEL {
  private static final String DNS = "dns";

  @ElFunction(
      prefix = DNS,
      name = "isPrivate",
      description = "Returns true if this is a private IPv4 address."
  )
  public static boolean isPrivate(
      @ElParam("address") String address
  ) {
    try {
      return InetAddresses.forString(address).isSiteLocalAddress();
    } catch (Exception e) {
      return false;
    }
  }
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License. See accompanying LICENSE file.
-->
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.streamsets</groupId>
  <artifactId>example-el</artifactId>
  <version>1.0.0-SNAPSHOT</version>

  <properties>
    <datacollector-api.version>2.5.0.0</datacollector-api.version>
    <slf4j.version>1.7.7</slf4j.version>
    <guava.version>18.0</guava.version>
  </properties>

  <dependencies>
    <!-- Core StreamSets Dependencies for Stage Libraries -->
    <dependency>
      <groupId>com.streamsets</groupId>
      <artifactId>streamsets-datacollector-api</artifactId>
      <version>${datacollector-api.version}</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>${slf4j.version}</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>${slf4j.version}</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>com.google.guava</groupId>
      <artifactId>guava</artifactId>
      <version>${guava.version}</version>
      <scope>provided</scope>
    </dependency>
    <!-- end -->
  </dependencies>


  <build>
    <pluginManagement>
      <plugins>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-compiler-plugin</artifactId>
          <configuration>
            <source>1.8</source>
            <target>1.8</target>
          </configuration>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>