com.smartsheet.tin.filters.pkpublish.PKPublishFilterRules.java Source code

Introduction

Here is the source code for com.smartsheet.tin.filters.pkpublish.PKPublishFilterRules.java

Source

/**
* Copyright 2014-2015 Smartsheet.com, 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.
*
*/

/**
 * Manage a set of PKPublish filter rules.
 * Load rules specified in JSON (from a string or a file).
 * Perform comparisons of ReplDBMSEvent objects against the set of rules.
 */
package com.smartsheet.tin.filters.pkpublish;

import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.node.JsonNodeType;
import com.smartsheet.tin.filters.common.JsonFilterException;

import static com.smartsheet.tin.filters.common.JsonFilterTools.fetchChildByName;
import static com.smartsheet.tin.filters.common.JsonFilterTools.confirmNodeType;
import com.continuent.tungsten.replicator.event.ReplDBMSEvent;

import org.apache.log4j.Logger;

/**
 * @author scott.wimer@smartsheet.com
 * 
 */
public class PKPublishFilterRules {
    private static Logger logger = Logger.getLogger(PKPublishFilterRules.class);
    private List<TransactionFilter> transaction_filters;

    public PKPublishFilterRules() {
        this.transaction_filters = new ArrayList<TransactionFilter>();
    }

    /**
     * Load the filter rules from a JSON-formatted string.
     * 
     * @param rules_json JSON formatted string of the filter rules.
     * @throws PKPublishFilterException
     * @throws IOException
     * @throws JsonFilterException 
     * @throws JsonProcessingException
     */
    public void loadRules(String rules_json) throws IOException, JsonFilterException {
        try {
            JsonNode rules_jn = new ObjectMapper().readTree(rules_json);
            confirmNodeType(rules_jn, JsonNodeType.OBJECT, "TransactionRules", logger);
            JsonNode transaction_filters_jn = fetchChildByName(rules_jn, "transaction_filters", "array");

            for (JsonNode tfilter_jn : transaction_filters_jn) {
                confirmNodeType(tfilter_jn, JsonNodeType.OBJECT, "TransactionFilter", logger);
                TransactionFilter tfilter = TransactionFilter.newFromJson(tfilter_jn);
                this.transaction_filters.add(tfilter);
                logger.debug("Added Transaction filter");
            }
        } catch (JsonProcessingException e) {
            throw new JsonFilterException(e);
        }
    }

    /**
     * Load the filter rules from a file.
     * 
     * @param path
     * @throws IOException
     * @throws JsonFilterException 
     * @throws PKPublishFilterException
     * 
     * 
     */
    public void loadRulesFromFile(String path) throws IOException, JsonFilterException {
        String rules = this.readFile(path);
        this.loadRules(rules);
    }

    /**
     * Apply the filters to a replication event (at transaction).
     * 
     * The returned list of TransactionMatchResult objects should be walked
     * and any messages from each match result should be handled
     * appropriately.
     * 
     * @param event The Event to apply the filters to.
     * @return A list of TransactionMatchResult objects.
     */
    public List<TransactionMatchResultAccumulator> apply(ReplDBMSEvent event) {
        List<TransactionMatchResultAccumulator> results = new ArrayList<TransactionMatchResultAccumulator>();
        for (TransactionFilter tf : this.transaction_filters) {
            results.add(tf.match(event));
        }
        return results;
    }

    /**
     * Read the specified file into a String.
     * 
     * @param path
     * @return
     * @throws IOException
     */
    private String readFile(String path) throws IOException {
        Path p = FileSystems.getDefault().getPath(path);
        String contents = new String(Files.readAllBytes(p));
        return contents;
    }

}