// TODO Auto-generated method stub
//Read data from hdfs
public List<LineChart> LineChartGen(String filePath, String dataType, List<String> columns, List<String> columnNames)
			throws IllegalArgumentException {
		// TODO Auto-generated method stub
		//Read data from hdfs
		List<String> results = readAllData(filePath,true); //Only read limited line data(if the data length over max length)
		List<LineChart> lineCharts = new ArrayList<LineChart>();
		for(String  selectedCol : columnNames)
		{
			LineChart lineChart =  singleLineGen(results, dataType, columns, selectedCol);
			if(lineChart == null)
				continue;
			else
				lineCharts.add(lineChart);
		}
		return lineCharts;
	}
public List<LineChart> LineChartGen(String filePath, String dataType, List<String> columns, List<String> columnNames)
throws IllegalArgumentException {
// TODO Auto-generated method stub
//Read data from hdfs
List<String> results = readAllData(filePath,true); //Only read limited line data(if the data length over max length)
List<LineChart> lineCharts = new ArrayList<LineChart>();
public List<LineChart> LineChartGen(String filePath, String dataType, List<String> columns, List<String> columnNames)
throws IllegalArgumentException {
// TODO Auto-generated method stub
//Read data from hdfs
List<String> results = readAllData(filePath,true); //Only read limited line data(if the data length over max length)
List<LineChart> lineCharts = new ArrayList<LineChart>();
for(String selectedCol : columnNames)
{
LineChart lineChart = singleLineGen(results, dataType, columns, selectedCol);
if(lineChart == null)
continue;
else
lineCharts.add(lineChart);
}
public List<LineChart> LineChartGen(String filePath, String dataType, List<String> columns, List<String> columnNames)
throws IllegalArgumentException {
// TODO Auto-generated method stub
//Read data from hdfs
List<String> results = readAllData(filePath,true); //Only read limited line data(if the data length over max length)
List<LineChart> lineCharts = new ArrayList<LineChart>();
for(String selectedCol : columnNames)
{
LineChart lineChart = singleLineGen(results, dataType, columns, selectedCol);
if(lineChart == null)
continue;
else
lineCharts.add(lineChart);
}
return lineCharts;
}