Package org.springframework.batch.sample.domain.multiline

Class AggregateItemReader<T>

  • All Implemented Interfaces:
    ItemReader<java.util.List<T>>
    public class AggregateItemReader<T>
extends java.lang.Object
implements ItemReader<java.util.List<T>>
    An ItemReader that delivers a list as its item, storing up objects from the injected ItemReader until they are ready to be packed out as a collection. This class must be used as a wrapper for a custom ItemReader that can identify the record boundaries. The custom reader should mark the beginning and end of records by returning an AggregateItem which responds true to its query methods is*().

    This class is thread-safe (it can be used concurrently by multiple threads) as long as the ItemReader is also thread-safe.
    Author:
    Dave Syer
    See Also:
    AggregateItem.isHeader(), AggregateItem.isFooter()

    • Constructor Detail

      • AggregateItemReader

        public AggregateItemReader()

    • Method Detail

      • read

        public java.util.List<T> read()
                       throws java.lang.Exception
        Get the next list of records.
        Specified by:
        read in interface ItemReader<T>
        Returns:
        T the item to be processed or null if the data source is exhausted
        Throws:
        ParseException - if there is a problem parsing the current record (but the next one may still be valid)
        NonTransientResourceException - if there is a fatal exception in the underlying resource. After throwing this exception implementations should endeavour to return null from subsequent calls to read.
        UnexpectedInputException - if there is an uncategorised problem with the input data. Assume potentially transient, so subsequent calls to read might succeed.
        java.lang.Exception - if an there is a non-specific error.
        See Also:
        ItemReader.read()