why using two big braces in below code？here it is not Anonymous inner class)

Question

I am studying Spring Batch,there is the below code， why using two big braces,I am confused. here it is not Anonymous inner class ,I think. who can help me?Thanks.

I am studying Spring Batch,there is the below code， why using two big braces,I am confused. here it is not Anonymous inner class ,I think. who can help me?Thanks.

import com.wisely.ch9_2.domain.Person;
import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.launch.support.RunIdIncrementer;
import org.springframework.batch.core.launch.support.SimpleJobLauncher;
import org.springframework.batch.core.repository.JobRepository;
import org.springframework.batch.core.repository.support.JobRepositoryFactoryBean;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.batch.item.ItemReader;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.item.database.BeanPropertyItemSqlParameterSourceProvider;
import org.springframework.batch.item.database.JdbcBatchItemWriter;
import org.springframework.batch.item.file.FlatFileItemReader;
import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper;
import org.springframework.batch.item.file.mapping.DefaultLineMapper;
import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
import org.springframework.batch.item.validator.Validator;
import org.springframework.context.annotation.Bean;
import org.springframework.core.io.ClassPathResource;
import org.springframework.transaction.PlatformTransactionManager;

import javax.sql.DataSource;

//@Configuration
@EnableBatchProcessing
public class CsvBatchConfig {

    @Bean
    public ItemReader<Person> reader() throws Exception {
        FlatFileItemReader<Person> reader = new FlatFileItemReader<Person>(); //1
        reader.setResource(new ClassPathResource("people.csv")); //2
        reader.setLineMapper(new DefaultLineMapper<Person>() {{ //3
            setLineTokenizer(new DelimitedLineTokenizer() {{
                setNames(new String[]{"name", "age", "nation", "address"});
            }});
            setFieldSetMapper(new BeanWrapperFieldSetMapper<Person>() {{
                setTargetType(Person.class);
            }});
        }});
        return reader;
    }

    @Bean
    public ItemProcessor<Person, Person> processor() {
        CsvItemProcessor processor = new CsvItemProcessor(); //1
        processor.setValidator(csvBeanValidator()); //2
        return processor;
    }


    @Bean
    public ItemWriter<Person> writer(DataSource dataSource) {//1
        JdbcBatchItemWriter<Person> writer = new JdbcBatchItemWriter<Person>(); //2
        writer.setItemSqlParameterSourceProvider(new BeanPropertyItemSqlParameterSourceProvider<Person>());
        String sql = "insert into person " + "(id,name,age,nation,address) "
                + "values(hibernate_sequence.nextval, :name, :age, :nation,:address)";
        writer.setSql(sql); //3
        writer.setDataSource(dataSource);
        return writer;
    }

    @Bean
    public JobRepository jobRepository(DataSource dataSource, PlatformTransactionManager transactionManager)
            throws Exception {
        JobRepositoryFactoryBean jobRepositoryFactoryBean = new JobRepositoryFactoryBean();
        jobRepositoryFactoryBean.setDataSource(dataSource);
        jobRepositoryFactoryBean.setTransactionManager(transactionManager);
        jobRepositoryFactoryBean.setDatabaseType("oracle");
        return jobRepositoryFactoryBean.getObject();
    }

    @Bean
    public SimpleJobLauncher jobLauncher(DataSource dataSource, PlatformTransactionManager transactionManager)
            throws Exception {
        SimpleJobLauncher jobLauncher = new SimpleJobLauncher();
        jobLauncher.setJobRepository(jobRepository(dataSource, transactionManager));
        return jobLauncher;
    }

    @Bean
    public Job importJob(JobBuilderFactory jobs, Step s1) {
        return jobs.get("importJob")
                .incrementer(new RunIdIncrementer())
                .flow(s1) //1
                .end()
                .listener(csvJobListener()) //2
                .build();
    }

    @Bean
    public Step step1(StepBuilderFactory stepBuilderFactory, ItemReader<Person> reader, ItemWriter<Person> writer,
                      ItemProcessor<Person, Person> processor) {
        return stepBuilderFactory
                .get("step1")
                .<Person, Person>chunk(65000) //1
                .reader(reader) //2
                .processor(processor) //3
                .writer(writer) //4
                .build();
    }


    @Bean
    public CsvJobListener csvJobListener() {
        return new CsvJobListener();
    }

    @Bean
    public Validator<Person> csvBeanValidator() {
        return new CsvBeanValidator<Person>();
    }



}