TextLengthAnalyzer.java

// ============================================================================
//
// Copyright (C) 2006-2016 Talend Inc. - www.talend.com
//
// This source code is available under agreement available at
// %InstallDIR%\features\org.talend.rcp.branding.%PRODUCTNAME%\%PRODUCTNAME%license.txt
//
// You should have received a copy of the agreement
// along with this program; if not, write to Talend SA
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package org.talend.dataquality.statistics.text;

import java.util.List;

import org.talend.dataquality.common.inference.Analyzer;
import org.talend.dataquality.common.inference.ResizableList;

/**
 * Text length analyzer compute the length of min,max and average length of the record sets.<br>
 * For more details please refer to documentation: <a
 * href="https://help.talend.com/pages/viewpage.action?pageId=261412880&thc_login=done">Text statistics</a>
 * 
 * @author zhao
 *
 */
public class TextLengthAnalyzer implements Analyzer<TextLengthStatistics> {

    private static final long serialVersionUID = -9106960246571082963L;

    private ResizableList<TextLengthStatistics> textStatistics = new ResizableList<>(TextLengthStatistics.class);

    @Override
    public void init() {
        textStatistics.clear();
    }

    @Override
    public boolean analyze(String... record) {
        if (record == null) {
            return true;
        }
        textStatistics.resize(record.length);
        for (int i = 0; i < record.length; i++) {
            TextLengthStatistics freqStats = textStatistics.get(i);
            freqStats.add(record[i]);
        }
        return true;
    }

    @Override
    public void end() {
        // Nothing to be done.

    }

    @Override
    public List<TextLengthStatistics> getResult() {
        return textStatistics;
    }

    @Override
    public Analyzer<TextLengthStatistics> merge(Analyzer<TextLengthStatistics> another) {
        int idx = 0;
        TextLengthAnalyzer mergedTextLengthAnalyzer = new TextLengthAnalyzer();
        ((ResizableList<TextLengthStatistics>) mergedTextLengthAnalyzer.getResult()).resize(textStatistics.size());
        for (TextLengthStatistics stats : textStatistics) {
            TextLengthStatistics mergedStats = mergedTextLengthAnalyzer.getResult().get(idx);
            TextLengthStatistics anotherStats = another.getResult().get(idx);
            mergedStats.setCount(stats.getCount() + anotherStats.getCount());
            mergedStats.setCountIgnoreBlank(stats.getCountIgnoreBlank() + anotherStats.getCountIgnoreBlank());

            // Merge min
            mergedStats.setMinTextLength(mergeMinMaxStats(stats.getMinTextLength(), anotherStats.getMinTextLength(), true));
            mergedStats.setMinTextLengthIgnoreBlank(mergeMinMaxWithBlankStats(stats.getMinTextLengthIgnoreBlank(),
                    anotherStats.getMinTextLengthIgnoreBlank(), true));
            // Merge max
            mergedStats.setMaxTextLength(mergeMinMaxStats(stats.getMaxTextLength(), anotherStats.getMaxTextLength(), false));
            mergedStats.setMaxTextLengthIgnoreBlank(mergeMinMaxWithBlankStats(stats.getMaxTextLengthIgnoreBlank(),
                    anotherStats.getMaxTextLengthIgnoreBlank(), false));
            // Merge sum
            mergedStats.setSumTextLength(mergeSumStats(stats.getSumTextLength(), anotherStats.getSumTextLength()));
            mergedStats.setSumTextLengthIgnoreBlank(
                    mergeSumStats(stats.getSumTextLengthIgnoreBlank(), anotherStats.getSumTextLengthIgnoreBlank()));

            idx++;
        }
        return mergedTextLengthAnalyzer;
    }

    private Integer mergeMinMaxStats(Integer one, Integer another, boolean isMin) {
        if (isMin) {
            return one < another ? one : another;
        } else {
            return one > another ? one : another;
        }
    }

    private Integer mergeMinMaxWithBlankStats(Integer one, Integer another, boolean isMin) {
        if (one == null || one == 0) {
            return another;
        } else {
            if (another != null && another != 0) {
                if (isMin) {
                    return one < another ? one : another;
                } else {
                    return one > another ? one : another;
                }
            } else {
                return one;
            }
        }
    }

    private Integer mergeSumStats(Integer one, Integer another) {
        if (one == null) {
            return another;
        } else {
            if (another != null) {
                return one + another;
            } else {
                return one;
            }
        }
    }

    @Override
    public void close() throws Exception {

    }

}