问如何使用FlatFileReader读取但只向ExecutionContext写入

EN

public class ProcessTabcPermitsTasklet implements Tasklet, StepExecutionListener {

    private Resource resource;
    private int linesToSkip;
    private Set<String> permits = new TreeSet<String>();

    public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext)  throws Exception {

        BufferedReader reader = new BufferedReader((new FileReader(resource.getFile())));
        String line = null;
        int lines = 0;

        while ((line = reader.readLine()) != null) {

            if (++lines <= linesToSkip)
                continue;

            String[] s = StringUtils.commaDelimitedListToStringArray(line);
            permits.add(s[TABC_COLUMNS.PERMIT.ordinal()]);

        }

        return RepeatStatus.FINISHED;
    }

    /**
     * @param file
     *            the file to set
     */
    public void setResource(Resource resource) {
        this.resource = resource;
    }

    /**
     * @param linesToSkip
     *            the linesToSkip to set
     */
    public void setLinesToSkip(int linesToSkip) {
        this.linesToSkip = linesToSkip;
    }


    public ExitStatus afterStep(StepExecution stepExecution) {
        stepExecution.getExecutionContext().put(EXECUTION_CONTEXT.TABC_PERMITS.toString(), permits);
        return ExitStatus.COMPLETED;
    }

}