| /** |
| * Licensed to 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.datatorrent.lib.filter; |
| |
| import java.util.LinkedList; |
| import java.util.List; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| import com.datatorrent.api.AutoMetric; |
| import com.datatorrent.api.Context; |
| import com.datatorrent.api.Context.PortContext; |
| import com.datatorrent.api.DefaultInputPort; |
| import com.datatorrent.api.DefaultOutputPort; |
| |
| import com.datatorrent.api.Operator; |
| import com.datatorrent.api.annotation.InputPortFieldAnnotation; |
| |
| import com.datatorrent.common.util.BaseOperator; |
| import com.datatorrent.lib.expression.Expression; |
| import com.datatorrent.lib.util.PojoUtils; |
| |
| /** |
| * <b>FilterOperator</b> |
| * Filter Operator filter out tuples based on defined condition |
| * |
| * <b>Parameters</b> |
| * - condition: condition based on expression language |
| * |
| * <b>Input Port</b> takes POJOs as an input |
| * |
| * <b>Output Ports</b> |
| * - truePort emits POJOs meeting the given condition |
| * - falsePort emits POJOs not meeting the given condition |
| * - error port emits any error situation while evaluating expression |
| * |
| * |
| * @since 3.5.0 |
| */ |
| @InterfaceStability.Evolving |
| public class FilterOperator extends BaseOperator implements Operator.ActivationListener |
| { |
| private String condition; |
| private List<String> expressionFunctions = new LinkedList<>(); |
| |
| private transient Class<?> inClazz = null; |
| private transient Expression<Boolean> expr = null; |
| |
| @AutoMetric |
| private long trueTuples; |
| |
| @AutoMetric |
| private long falseTuples; |
| |
| @AutoMetric |
| private long errorTuples; |
| |
| public final transient DefaultOutputPort<Object> truePort = new DefaultOutputPort<Object>(); |
| |
| public final transient DefaultOutputPort<Object> falsePort = new DefaultOutputPort<Object>(); |
| |
| public final transient DefaultOutputPort<Object> error = new DefaultOutputPort<Object>(); |
| |
| public FilterOperator() |
| { |
| expressionFunctions.add("java.lang.Math.*"); |
| expressionFunctions.add("org.apache.commons.lang3.StringUtils.*"); |
| expressionFunctions.add("org.apache.commons.lang3.StringEscapeUtils.*"); |
| expressionFunctions.add("org.apache.commons.lang3.time.DurationFormatUtils.*"); |
| expressionFunctions.add("org.apache.commons.lang3.time.DateFormatUtils.*"); |
| } |
| |
| @InputPortFieldAnnotation(schemaRequired = true) |
| public final transient DefaultInputPort<Object> input = new DefaultInputPort<Object>() |
| { |
| public void setup(PortContext context) |
| { |
| inClazz = context.getValue(Context.PortContext.TUPLE_CLASS); |
| } |
| |
| @Override |
| public void process(Object t) |
| { |
| processTuple(t); |
| } |
| }; |
| |
| @Override |
| public void activate(Context context) |
| { |
| createExpression(); |
| } |
| |
| @Override |
| public void deactivate() |
| { |
| } |
| |
| @Override |
| public void beginWindow(long windowId) |
| { |
| errorTuples = trueTuples = falseTuples = 0; |
| } |
| |
| /** |
| * createExpression: create an expression from condition of POJO fields |
| * Override this function for custom field expressions |
| */ |
| protected void createExpression() |
| { |
| logger.info("Creating an expression for condition {}", condition); |
| expr = PojoUtils.createExpression(inClazz, condition, Boolean.class, |
| expressionFunctions.toArray(new String[expressionFunctions.size()])); |
| } |
| |
| /** |
| * evalExpression: Evaluate condition/expression |
| * Override this function for custom condition evaluation |
| */ |
| protected Boolean evalExpression(Object t) |
| { |
| return expr.execute(t); |
| } |
| |
| /** |
| * handleFilter: emit POJO meeting condition on truePort |
| * and if it did not meet condition then on falsePort |
| */ |
| private void processTuple(Object t) |
| { |
| try { |
| if (evalExpression(t)) { |
| truePort.emit(t); |
| trueTuples++; |
| } else { |
| falsePort.emit(t); |
| falseTuples++; |
| } |
| } catch (Exception ex) { |
| logger.error("Error in expression eval: {}", ex.getMessage()); |
| logger.debug("Exception: ", ex); |
| error.emit(t); |
| errorTuples++; |
| } |
| } |
| |
| /** |
| * Returns condition/expression with which Filtering is done |
| * |
| * @return condition parameter of Filter Operator |
| */ |
| public String getCondition() |
| { |
| return condition; |
| } |
| |
| /** |
| * Set condition/expression with which Filtering operation would be applied |
| * |
| * @param condition parameter of Filter Operator |
| */ |
| public void setCondition(String condition) |
| { |
| logger.info("Changing condition from {} to {}", this.condition, condition); |
| this.condition = condition; |
| } |
| |
| /** |
| * Returns the list of expression function which would be made available to |
| * expression to use. |
| * |
| * @return List of functions available in expression. |
| */ |
| public List<String> getExpressionFunctions() |
| { |
| return expressionFunctions; |
| } |
| |
| /** |
| * Set list of import classes/method should should be made statically available |
| * to expression to use. |
| * For ex. org.apache.apex.test1.Test would mean that "Test" method will be |
| * available in the expression to be used directly. |
| * This is an optional property. See constructor to see defaults that are included. |
| * |
| * @param expressionFunctions List of qualified class/method that needs to be |
| * imported to expression. |
| */ |
| public void setExpressionFunctions(List<String> expressionFunctions) |
| { |
| this.expressionFunctions = expressionFunctions; |
| } |
| |
| private static final Logger logger = LoggerFactory.getLogger(FilterOperator.class); |
| } |