(Spring-Batch) Example implementation wraps a MultiResourceItemReader to get the current resource.

WrappedMrirToGetCurrentResource.java

public class WrappedMrirToGetCurrentResource<T> implements ItemStreamReader<T> {

    private MultiResourceItemReader<T> mrir;

    @Override
    public void open(ExecutionContext executionContext) throws ItemStreamException {
        mrir.open(executionContext);
        // current.resource is only available here if it's a restart
        if (mrir.getCurrentResource() != null && mrir.getCurrentResource().getFilename() != null) {
            System.out.println("open:" + mrir.getCurrentResource().getFilename());
        }
    }

    @Override
    public void update(ExecutionContext executionContext) throws ItemStreamException {
        mrir.update(executionContext);
        // one of the most reliable positions to get the current.resource
        if (mrir.getCurrentResource() != null && mrir.getCurrentResource().getFilename() != null) {
            System.out.println("update:" + mrir.getCurrentResource().getFilename());
        }
    }

    @Override
    public void close() throws ItemStreamException {
        mrir.close();
    }

    @Override
    public T read() throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {
        T result = mrir.read();
        // another position to get the actual current.resource, has to be called
        // after the first read
        if (mrir.getCurrentResource() != null && mrir.getCurrentResource().getFilename() != null) {
            System.out.println("read:" + mrir.getCurrentResource().getFilename());
        }
        return result;
    }

    public void setMrir(MultiResourceItemReader<T> mrir) {
        this.mrir = mrir;
    }
}