net.sf.jasperreports.engine

## Class JREmptyDataSource

- java.lang.Object
- - net.sf.jasperreports.engine.JREmptyDataSource

- All Implemented Interfaces:
    JRDataSource, JRRewindableDataSource

      public class JREmptyDataSource
      extends java.lang.Object
      implements JRRewindableDataSource

  A simple data source implementation that simulates a data source with a given number of virtual records inside. It is called empty data source because even though it has one or more records inside, all the report fields are null for all the virtual records of the data source.

  The simplest implementation of the `JRDataSource` interface, this class can be used in reports that do not display data from the supplied data source, but rather from parameters, and when only the number of virtual rows in the data source is important.

  Version:
    $Id: JREmptyDataSource.java 7017 2014-04-15 10:18:40Z shertage $
  Author:
    Teodor Danciu (teodord@users.sourceforge.net)
  See Also:
    `JRDataSource`

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `JREmptyDataSource()`
    `JREmptyDataSource(int count)`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `java.lang.Object` | `getFieldValue(JRField field)` Gets the field value for the current position.
    `void` | `moveFirst()` Moves back to the first element in the data source.
    `boolean` | `next()` Tries to position the cursor on the next element in the data source.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### JREmptyDataSource

          public JREmptyDataSource()

    - #### JREmptyDataSource

          public JREmptyDataSource(int count)

  - ### Method Detail

    - #### next

          public boolean next()

      Description copied from interface: `JRDataSource`
      Tries to position the cursor on the next element in the data source.
      Specified by:
        `next` in interface `JRDataSource`
      Returns:
        true if there is a next record, false otherwise

    - #### getFieldValue

          public java.lang.Object getFieldValue(JRField field)

      Description copied from interface: `JRDataSource`
      Gets the field value for the current position.
      Specified by:
        `getFieldValue` in interface `JRDataSource`
      Returns:
        an object containing the field value. The object type must be the field object type.

    - #### moveFirst

          public void moveFirst()

      Description copied from interface: `JRRewindableDataSource`
      Moves back to the first element in the data source.
      Specified by:
        `moveFirst` in interface `JRRewindableDataSource`

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