com.nextdoor.bender.operation.json.key.KeyNameReplacementOperation.java Source code

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Here is the source code for com.nextdoor.bender.operation.json.key.KeyNameReplacementOperation.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.json.key;

import java.util.HashSet;
import java.util.Map.Entry;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.nextdoor.bender.operation.json.PayloadOperation;

/**
 * In place recursively mutates a {@link JsonObject} to replace parts of a key with a value. This is
 * typically used to sanitize key names.
 */
public class KeyNameReplacementOperation extends PayloadOperation {
    public final Pattern pattern;
    public final String replacement;
    private final boolean drop;

    public KeyNameReplacementOperation(final Pattern pattern, String replacement, boolean drop) {
        this.pattern = pattern;
        this.replacement = replacement;
        this.drop = drop;
    }

    protected void performOnArray(JsonElement elm) {
        if (elm.isJsonObject()) {
            perform(elm.getAsJsonObject());
        } else if (elm.isJsonArray()) {
            JsonArray arr = elm.getAsJsonArray();
            arr.forEach(item -> {
                performOnArray(item);
            });
        }
    }

    protected void perform(JsonObject obj) {
        Set<Entry<String, JsonElement>> entries = obj.entrySet();
        Set<Entry<String, JsonElement>> orgEntries = new HashSet<Entry<String, JsonElement>>(entries);

        for (Entry<String, JsonElement> entry : orgEntries) {
            JsonElement val = entry.getValue();

            /*
             * See if key matches. If it does then drop or rename. Otherwise keep recursing.
             */
            Matcher m = this.pattern.matcher(entry.getKey());
            boolean found = m.find();
            if (found) {
                /*
                 * If instructed to drop then remove and continue. Otherwise remove and later rename;
                 */
                obj.remove(entry.getKey());
                if (this.drop) {
                    continue;
                }

                /*
                 * Rename
                 */
                if (val.isJsonPrimitive()) {
                    obj.add(m.replaceAll(this.replacement), val);
                } else if (val.isJsonObject()) {
                    obj.add(m.replaceAll(this.replacement), val);
                    perform(val.getAsJsonObject());
                } else if (val.isJsonArray()) {
                    JsonArray arr = val.getAsJsonArray();

                    arr.forEach(item -> {
                        performOnArray(item);
                    });
                    obj.add(m.replaceAll(this.replacement), val);
                }
                continue;
            }

            /*
             * Keep recursing
             */
            if (val.isJsonObject()) {
                perform(val.getAsJsonObject());
            } else if (val.isJsonArray()) {
                JsonArray arr = val.getAsJsonArray();
                arr.forEach(item -> {
                    performOnArray(item);
                });
            }

        }
    }
}