com.metamx.common.parsers.JSONToLowerParser.java Source code

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Here is the source code for com.metamx.common.parsers.JSONToLowerParser.java

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/*
 * Copyright 2011,2012 Metamarkets Group Inc.
 *
 * 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.
 */

package com.metamx.common.parsers;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * TODO:
 * There is a lot of code copy and pasted from JSONParser. JSONParser needs to be rewritten
 * to actually take a map transformer instead of what it is doing now. For the purposes of moving forward in 0.7.0,
 * I am going to have a different parser to lower case data from JSON. This code needs to be removed the next time
 * we touch java-util.
 */
@Deprecated
public class JSONToLowerParser extends JSONParser {
    private final ObjectMapper objectMapper;
    private final Set<String> exclude;

    private ArrayList<String> fieldNames;

    public JSONToLowerParser(ObjectMapper objectMapper, Iterable<String> fieldNames, Iterable<String> exclude) {
        super(objectMapper, fieldNames, exclude);
        this.objectMapper = objectMapper;
        if (fieldNames != null) {
            setFieldNames(fieldNames);
        }
        this.exclude = exclude != null
                ? Sets.newHashSet(Iterables.transform(exclude, new Function<String, String>() {
                    @Override
                    public String apply(String input) {
                        return input.toLowerCase();
                    }
                }))
                : Sets.<String>newHashSet();
    }

    @Override
    public Map<String, Object> parse(String input) {
        try {
            Map<String, Object> map = new LinkedHashMap<>();
            JsonNode root = objectMapper.readTree(input);

            Iterator<String> keysIter = (fieldNames == null ? root.fieldNames() : fieldNames.iterator());

            while (keysIter.hasNext()) {
                String key = keysIter.next();

                if (exclude.contains(key.toLowerCase())) {
                    continue;
                }

                JsonNode node = root.path(key);

                if (node.isArray()) {
                    final List<Object> nodeValue = Lists.newArrayListWithExpectedSize(node.size());
                    for (final JsonNode subnode : node) {
                        final Object subnodeValue = valueFunction.apply(subnode);
                        if (subnodeValue != null) {
                            nodeValue.add(subnodeValue);
                        }
                    }
                    map.put(key.toLowerCase(), nodeValue); // difference from JSONParser parse()
                } else {
                    final Object nodeValue = valueFunction.apply(node);
                    if (nodeValue != null) {
                        map.put(key.toLowerCase(), nodeValue); // difference from JSONParser parse()
                    }
                }
            }
            return map;
        } catch (Exception e) {
            throw new ParseException(e, "Unable to parse row [%s]", input);
        }
    }
}