com.nextdoor.bender.operation.substitution.regex.RegexSubstitution.java Source code

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Here is the source code for com.nextdoor.bender.operation.substitution.regex.RegexSubstitution.java

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/*
 * 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.
 *
 * Copyright 2018 Nextdoor.com, Inc
 *
 */

package com.nextdoor.bender.operation.substitution.regex;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.lang3.math.NumberUtils;
import org.apache.commons.lang3.tuple.ImmutablePair;
import org.apache.commons.lang3.tuple.Pair;
import com.nextdoor.bender.InternalEvent;
import com.nextdoor.bender.deserializer.DeserializedEvent;
import com.nextdoor.bender.deserializer.FieldNotFoundException;
import com.nextdoor.bender.operation.OperationException;
import com.nextdoor.bender.operation.substitution.Substitution;
import com.nextdoor.bender.operation.substitution.regex.RegexSubstitutionConfig.RegexSubField;

public class RegexSubstitution extends Substitution {
    private final List<String> srcFields;
    private final Pattern pattern;
    private final List<RegexSubField> fields;
    private final boolean removeSrcField;
    private final boolean failSrcNotFound;
    private final boolean failDstNotFound;

    public RegexSubstitution(List<String> srcFields, Pattern pattern, List<RegexSubField> fields,
            boolean removeSrcField, boolean failSrcNotFound, boolean failDstNotFound) {
        this.srcFields = srcFields;
        this.pattern = pattern;
        this.fields = fields;
        this.removeSrcField = removeSrcField;
        this.failSrcNotFound = failSrcNotFound;
        this.failDstNotFound = failDstNotFound;
    }

    @Override
    protected void doSubstitution(InternalEvent ievent, DeserializedEvent devent, Map<String, Object> nested) {
        Pair<String, Map<String, Object>> kv;
        try {
            kv = getRegexMatches(devent);
        } catch (FieldNotFoundException e) {
            if (this.failSrcNotFound) {
                throw new OperationException(e);
            }
            return;
        }

        nested.putAll(kv.getValue());

        /*
         * Remove source field
         */
        if (this.removeSrcField) {
            try {
                devent.removeField(kv.getKey());
            } catch (FieldNotFoundException e) {
                if (this.failSrcNotFound) {
                    throw new OperationException(e);
                }
            }
        }
    }

    @Override
    protected void doSubstitution(InternalEvent ievent, DeserializedEvent devent) {
        Pair<String, Map<String, Object>> kv;
        try {
            kv = getRegexMatches(devent);
        } catch (FieldNotFoundException e) {
            if (this.failSrcNotFound) {
                throw new OperationException(e);
            }
            return;
        }

        ((Map<String, Object>) kv.getValue()).forEach((k, v) -> {
            try {
                devent.setField(k, v);
            } catch (FieldNotFoundException e) {
                if (this.failDstNotFound) {
                    throw new OperationException(e);
                }
            }
        });

        /*
         * Do not remove source field if it has been replaced by a regex group.
         */
        if (this.removeSrcField && !kv.getValue().containsKey(kv.getKey())) {
            try {
                devent.removeField(kv.getKey());
            } catch (FieldNotFoundException e) {
                if (this.failSrcNotFound) {
                    throw new OperationException(e);
                }
            }
        }
    }

    /**
     * Matches a regex against a field and extracts matching groups.
     * 
     * @param devent
     * @param config
     * @return
     * @throws FieldNotFoundException
     */
    private Pair<String, Map<String, Object>> getRegexMatches(DeserializedEvent devent)
            throws FieldNotFoundException {
        String foundSourceField = null;
        Matcher matcher = null;

        for (String sourceField : this.srcFields) {
            String sourceValue;
            try {
                sourceValue = devent.getFieldAsString(sourceField);
            } catch (FieldNotFoundException e) {
                continue;
            }

            matcher = pattern.matcher(sourceValue);

            if (matcher.find()) {
                /*
                 * Keep track of the field name that we use so it can be removed later.
                 */
                foundSourceField = sourceField;
                break;
            }
        }

        if (foundSourceField == null) {
            throw new FieldNotFoundException("unable to find field in: " + this.srcFields);
        }

        /*
         * Go through each match group in the field config and attempt to add that match group from the
         * regex match. If field type coercion does not succeed then field is skipped.
         */
        Map<String, Object> matchedGroups = new HashMap<String, Object>(matcher.groupCount());
        try {
            for (RegexSubField field : this.fields) {
                String matchStrVal = matcher.group(field.getRegexGroupName());

                if (matchStrVal == null) {
                    continue;
                }

                switch (field.getType()) {
                case BOOLEAN:
                    matchedGroups.put(field.getKey(), Boolean.parseBoolean(matchStrVal));
                    break;
                case NUMBER:
                    matchedGroups.put(field.getKey(), NumberUtils.createNumber(matchStrVal));
                    break;
                case STRING:
                    matchedGroups.put(field.getKey(), matchStrVal);
                    break;
                default:
                    matchedGroups.put(field.getKey(), matchStrVal);
                    break;
                }
            }
        } catch (NumberFormatException e) {
            throw new FieldNotFoundException("matched field is not a number");
        }

        return new ImmutablePair<String, Map<String, Object>>(foundSourceField, matchedGroups);
    }
}