tech.tablesaw.io.TableBuildingUtils Maven / Gradle / Ivy

Go to download
package tech.tablesaw.io;

import java.io.ByteArrayInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.Iterator;
import java.util.List;

import tech.tablesaw.api.ColumnType;
import tech.tablesaw.api.Table;

public class TableBuildingUtils {

    public static Reader createReader(ReadOptions options, byte[] cachedBytes) throws IOException {
	if (cachedBytes != null) {
	    return new InputStreamReader(new ByteArrayInputStream(cachedBytes));
	}
        if (options.inputStream() != null) {
            return new InputStreamReader(options.inputStream());
        }
        if (options.reader() != null) {
            return options.reader();
        }
        return new FileReader(options.file());
    }

    public static Table build(List columnNames, List dataRows, ReadOptions options) {
        Table table = Table.create(options.tableName());

        if (dataRows.size() == 0) {
            return table;
        }

        ColumnTypeDetector detector = new ColumnTypeDetector();
        Iterator iterator = dataRows.iterator();
        ColumnType[] types = detector.detectColumnTypes(iterator, options);
        for (int i = 0; i < columnNames.size(); i++) {
            table.addColumns(types[i].create(columnNames.get(i)));
        }

        for (int i = 0; i < dataRows.size(); i++) {
            for (int j = 0; j < table.columnCount(); j++) {
                table.column(j).appendCell(dataRows.get(i)[j]);        	
            }
        }

        return table;
    }

}