FetchData (Javadocs [I2P+ 2.11.0+] - API Version 0.9.68+)

java.lang.Object
- org.rrd4j.core.FetchData

```
public class FetchData
extends Object
```
Class used to represent data fetched from the RRD. Object of this class is created when the method fetchData() is called on a FetchRequest object.
Data returned from the RRD is, simply, just one big table filled with timestamps and corresponding datasource values. Use getRowCount() method to count the number of returned timestamps (table rows).
The first table column is filled with timestamps. Time intervals between consecutive timestamps are guaranteed to be equal. Use getTimestamps() method to get an array of timestamps returned.
Remaining columns are filled with datasource values for the whole timestamp range, on a column-per-datasource basis. Use getColumnCount() to find the number of datasources and getValues(i) method to obtain all values for the i-th datasource. Returned datasource values correspond to the values returned with getTimestamps() method.
This data structure holds the fetched information.

Constructor Summary

Constructors
Constructor and Description

FetchData(Archive matchingArchive, FetchRequest request)

Constructors
Constructor and Description
`FetchData(Archive matchingArchive, FetchRequest request)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`String`	`dump()` Dumps the content of the whole FetchData object.
`String`	`exportXml()` Dumps fetch data in XML format.
`void`	`exportXml(OutputStream outputStream)` Dumps fetch data to output stream in XML format.
`void`	`exportXml(String filepath)` Dumps fetch data to file in XML format.
`void`	`exportXml(XmlWriter writer)`
`long`	`getArcEndTime()` Returns the timestamp of the last populated slot in the corresponding RRA archive
`long`	`getArcStep()` Returns the step of the corresponding RRA archive
`int`	`getColumnCount()` Returns the number of columns fetched from the corresponding RRD.
`int`	`getDsIndex(String dsName)` Retrieve the table index number of a datasource by name.
`String[]`	`getDsNames()` Returns array of datasource names found in the corresponding RRD.
`long`	`getFirstTimestamp()` Returns the first timestamp in this FetchData object.
`long`	`getLastTimestamp()` Returns the last timestamp in this FecthData object.
`Archive`	`getMatchingArchive()` Returns Archive object which is determined to be the best match for the timestamps specified in the fetch request.
`FetchRequest`	`getRequest()` Returns `FetchRequest` object used to create this FetchData object.
`int`	`getRowCount()` Returns the number of rows fetched from the corresponding RRD.
`double[]`	`getRpnValues(String rpnExpression)` Returns a set of values created by applying RPN expression to the fetched data.
`long`	`getStep()` Returns the step with which this data was fetched.
`long[]`	`getTimestamps()` Returns an array of timestamps covering the whole range specified in the `FetchReguest` object.
`double[][]`	`getValues()` Returns all archived values for all datasources.
`double[]`	`getValues(int dsIndex)` Returns all archived values for a single datasource.
`double[]`	`getValues(String dsName)` Returns all archived values for a single datasource.
`(package private) void`	`setTimestamps(long[] timestamps)` Sets the timestamps for the fetched data.
`(package private) void`	`setValues(double[][] values)` Sets the values for the fetched data.
`String`	`toString()` Returns string representing fetched data in a RRDTool-like form.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - FetchData
```
FetchData(Archive matchingArchive,
          FetchRequest request)
   throws IOException
```
    Throws:
    
    IOException
- Method Detail
  - dump
```
public String dump()
```
    Dumps the content of the whole FetchData object. Useful for debugging.
    
    Returns:
    
    a String containing the contents of this object, for debugging.
  - exportXml
```
public String exportXml()
```
    Dumps fetch data in XML format.
    
    Returns:
    
    String containing XML formatted fetch data
  - exportXml
```
public void exportXml(OutputStream outputStream)
```
    Dumps fetch data to output stream in XML format. A flush is issued at the end of the xml generation.
    
    Parameters:
    
    outputStream - Output stream to dump fetch data to
  - exportXml
```
public void exportXml(String filepath)
               throws IOException
```
    Dumps fetch data to file in XML format.
    
    Parameters:
    
    filepath - Path to destination file
    
    Throws:
    
    IOException - Thrown in case of I/O error
  - exportXml
```
public void exportXml(XmlWriter writer)
```
  - getArcEndTime
```
public long getArcEndTime()
```
    Returns the timestamp of the last populated slot in the corresponding RRA archive
    
    Returns:
    
    Timestamp in seconds
  - getArcStep
```
public long getArcStep()
```
    Returns the step of the corresponding RRA archive
    
    Returns:
    
    Archive step in seconds
  - getColumnCount
```
public int getColumnCount()
```
    Returns the number of columns fetched from the corresponding RRD. This number is always equal to the number of datasources defined in the RRD. Each column represents values of a single datasource.
    
    Returns:
    
    Number of columns (datasources).
  - getDsIndex
```
public int getDsIndex(String dsName)
```
    Retrieve the table index number of a datasource by name. Names are case sensitive.
    
    Parameters:
    
    dsName - Name of the datasource for which to find the index.
    
    Returns:
    
    Index number of the datasources in the value table.
  - getDsNames
```
public String[] getDsNames()
```
    Returns array of datasource names found in the corresponding RRD. If the request was filtered (data was fetched only for selected datasources), only datasources selected for fetching are returned.
    
    Returns:
    
    Array of datasource names.
  - getFirstTimestamp
```
public long getFirstTimestamp()
```
    Returns the first timestamp in this FetchData object.
    
    Returns:
    
    The smallest timestamp.
  - getLastTimestamp
```
public long getLastTimestamp()
```
    Returns the last timestamp in this FecthData object.
    
    Returns:
    
    The biggest timestamp.
  - getMatchingArchive
```
public Archive getMatchingArchive()
```
    Returns Archive object which is determined to be the best match for the timestamps specified in the fetch request. All datasource values are obtained from round robin archives belonging to this archive.
    
    Returns:
    
    Matching archive.
  - getRequest
```
public FetchRequest getRequest()
```
    Returns FetchRequest object used to create this FetchData object.
    
    Returns:
    
    Fetch request object.
  - getRowCount
```
public int getRowCount()
```
    Returns the number of rows fetched from the corresponding RRD. Each row represents datasource values for the specific timestamp.
    
    Returns:
    
    Number of rows.
  - getRpnValues
```
public double[] getRpnValues(String rpnExpression)
```
    Returns a set of values created by applying RPN expression to the fetched data. For example, if you have two datasources named x and y in this FetchData and you want to calculate values for (x+y)/2 use something like:
    getRpnValues("x,y,+,2,/");
    
    Parameters:
    
    rpnExpression - RRDTool-like RPN expression
    
    Returns:
    
    Calculated values
    
    Throws:
    
    IllegalArgumentException - Thrown if invalid RPN expression is supplied
  - getStep
```
public long getStep()
```
    Returns the step with which this data was fetched.
    
    Returns:
    
    Step as long.
  - getTimestamps
```
public long[] getTimestamps()
```
    Returns an array of timestamps covering the whole range specified in the FetchReguest object.
    
    Returns:
    
    Array of equidistant timestamps.
  - getValues
```
public double[][] getValues()
```
    Returns all archived values for all datasources. Returned values correspond to timestamps returned with getTimestamps() method.
    
    Returns:
    
    Two-dimensional aray of all datasource values.
  - getValues
```
public double[] getValues(int dsIndex)
```
    Returns all archived values for a single datasource. Returned values correspond to timestamps returned with getTimestamps() method.
    
    Parameters:
    
    dsIndex - Datasource index.
    
    Returns:
    
    Array of single datasource values.
  - getValues
```
public double[] getValues(String dsName)
```
    Returns all archived values for a single datasource. Returned values correspond to timestamps returned with getTimestamps() method.
    
    Parameters:
    
    dsName - Datasource name.
    
    Returns:
    
    Array of single datasource values.
  - setTimestamps
```
void setTimestamps(long[] timestamps)
```
    Sets the timestamps for the fetched data.
    
    Parameters:
    
    timestamps - array of timestamps
  - setValues
```
void setValues(double[][] values)
```
    Sets the values for the fetched data.
    
    Parameters:
    
    values - 2D array of values
  - toString
```
public String toString()
```
    Returns string representing fetched data in a RRDTool-like form.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    Fetched data as a string in a rrdfetch-like output form.

Class FetchData

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FetchData

Method Detail

dump

exportXml

exportXml

exportXml

exportXml

getArcEndTime

getArcStep

getColumnCount

getDsIndex

getDsNames

getFirstTimestamp

getLastTimestamp

getMatchingArchive

getRequest

getRowCount

getRpnValues

getStep

getTimestamps

getValues

getValues

getValues

setTimestamps

setValues

toString