Simple vs. Easy: Writing A Generic Code To Avoid Duplication - replacing a number of anemic data structures with a generic one - IMPROVED. See http://wondersofcode.wordpress.com/2013/05/04/simple-vs-easy…id-duplication/

LogEntry2.java

public interface LogEntry {
    // same as before
}

MapLogEntry.java

// The generic LogEntry implementation
// JavaDoc removed for the sake of brevity
public class MapLogEntry implements LogEntry {
    
    private static final char FIELD_SEPARATOR = '\t';
    private Map<String, String> fields = new HashMap<String, String>();
    private final String[][] columns;
    private final StringBuilder tabString = new StringBuilder();
    private final Date timestamp;
    private String key;
    
    public MapLogEntry(Date timestamp, String[][] columns) {
        this.timestamp = checkNotNull(timestamp, "timestamp");
        this.columns = checkNotNull(columns, "columns");
    }

    @Override
    public String toTabDelimitedString() {
        return tabString.toString();
    }
    
    public MapLogEntry addInOrder(String column, String value) {
        checkAndStoreColumnValue(column, value);
        appendToTabString(value);
        return this;
    }

    public MapLogEntry validated() throws IllegalStateException {
        if (fields.size() != columns.length) {
            throw new IllegalStateException("This entry doesn't contain values for all the columns " +
                	"expected (" + columns.length + "). Actual values (" + fields.size() + "): " + toTabDelimitedString());
        }
        return this;
    }

    private void checkAndStoreColumnValue(String column, String value) {
        final int addedColumnIndex = fields.size();
        checkElementIndex(addedColumnIndex, columns.length, "Cannot add more values, all " + columns.length +
                " columns already provided; column being added: " + column);
        String expectedColumn = columns[addedColumnIndex][0];
        if (!column.equals(expectedColumn)) {
            throw new IllegalArgumentException("Cannot store value for the column '" +
                    column + "', the column expected at the current position " + addedColumnIndex +
                    " is '" + expectedColumn + "'");
        }
        fields.put(column, value);
    }

    private void appendToTabString(String value) {
        if (tabString.length() > 0) {
            tabString.append(FIELD_SEPARATOR);
        }
        tabString.append(valOrNull(replaceFildSeparators(value)));
    }
    
    /** Encode value for outputting into a tab-delimited dump. */
    Object valOrNull(Object columnValue) {
        if (columnValue == null) {
            return HiveConstants.NULL_MARKER;
        }
        return columnValue;
    }

    @Override
    public Date getTimestamp() {
        return timestamp;
    }

    @Override
    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public MapLogEntry withKey(String key) {
        setKey(key);
        return this;
    }

    /**Utility method to simplify testing. */
    public Map<String, String> asFieldsMap() {
        return fields;
    }
    ...
}

PlayerEventsParser2.java

// Called from a data import job to process individual log lines.
// Some time later, the job will call toTabDelimitedString on it.
public class PlayerEventsParser ... {

   @Override
    public LogEntry parse(String logLine) throws LogParseException {
        ... // tokenizing, processing etc. of the data ...
        return new MapLogEntry(timestamp, getColumns())
                    .addInOrder("userid", userId)
                    .addInOrder("contentid", contentId)
                    .addInOrder("sessionid", sessionId)
                    ...
                    .validated();
    }
    
}