File Import rule - Georgetown-University-Libraries/File-Analyzer GitHub Wiki

File Import Rules act on a single file at one time. A File Import Rule generally reports on the status of each record that is found within a given file.

##Components of a File Import Rule

Name and description: explains the File Import Rule to a user

screen shot

public classclass CountKey extends DefaultImporter {

public String toString() {
    return "Count Key";
}
public String getDescription() {
    return "Count the number of times a key appears in a file.";
}
public String getShortName() {
    return "Key";
}

Properties: runtime parameters that the user can pass to the File Import Rule

screen shot

public static final String DELIM = "Delimiter";
public static final String HEADROW = "HeadRow";
public static final String COL = "COL";
public CountKey(FTDriver dt) {
    super(dt);
    this.ftprops.add(new FTPropEnum(dt, this.getClass().getName(), DELIM, "delim",
        "Delimiter character separating fields", Separator.values(), Separator.Comma));
    this.ftprops.add(new FTPropEnum(dt, this.getClass().getName(), HEADROW, HEADROW,
        "Treat first row as header", YN.values(), YN.Y));
    this.ftprops.add(new FTPropString(dt, this.getClass().getName(), COL, COL,
        "Key Column starting at 1", "1"));
}

Result Stats: defines the resulting information that will be displayed to the user (as a table)

screen shot

public static enum MULT {ONE, MANY;}
private static enum CountStatsItems implements StatsItemEnum {
    Key(StatsItem.makeStringStatsItem("Key", 100)),
    Count(StatsItem.makeIntStatsItem("Count")),
    Stat(StatsItem.makeEnumStatsItem(MULT.class, "Multiple?"))
    ;
    
    StatsItem si;
    CountStatsItems(StatsItem si) {this.si=si;}
    public StatsItem si() {return si;}
}
public static enum Generator implements StatsGenerator {
    INSTANCE;

    public Stats create(String key) {return new Stats(details, key);}
}

public static StatsItemConfig details = StatsItemConfig.create(CountStatsItems.class);

Code the File Import Rule

In the example displayed above, a checksum is generated on the file using the algorithm provided by the user.

public ActionResult importFile(File selectedFile) throws IOException {
    
    int col = 0;
    try {
        col = Integer.parseInt(this.getProperty(COL,"").toString());
        col--;
    } catch (NumberFormatException e) {
    }
    
    Separator fileSeparator = (Separator)getProperty(DELIM);
    Timer timer = new Timer();

    TreeMap<String,Stats> types = new TreeMap<String,Stats>();
    
    DelimitedFileReader dfr = new DelimitedFileReader(selectedFile, fileSeparator.separator);
    boolean firstRow = (YN)getProperty(HEADROW) == YN.Y;
    
    firstRow = (YN)getProperty(HEADROW) == YN.Y;
    dfr = new DelimitedFileReader(selectedFile, fileSeparator.separator);
    for(Vector<String> cols = dfr.getRow(); cols != null; cols = dfr.getRow()){
        if (firstRow) {
            firstRow = false;
            continue;
        }
        String key = cols.get(col < cols.size() ? col : 0);
        Stats stats = types.get(key);
        if (stats == null) {
            stats = Generator.INSTANCE.create(key);
            stats.setVal(CountStatsItems.Count, 1);
            stats.setVal(CountStatsItems.Stat, MULT.ONE);
            types.put(key, stats);
        } else {
            stats.sumVal(CountStatsItems.Count, 1);
            stats.setVal(CountStatsItems.Stat, MULT.MANY);
        }
    }
    
    return new ActionResult(selectedFile, selectedFile.getName(), this.toString(), details, types, true, timer.getDuration());
}

Register the Importer with the File Analyzer

public class ImporterRegistry extends Vector<Importer> {

private static final long serialVersionUID = 1L;

public ImporterRegistry(FTDriver dt) {
    ...
    add(new CountKey(dt));
}
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