写一个用Ehcache读取2G的CSV文件并缓存到临时文件中，最后以List<dto>的形式传出的demo

以下是一个基于 Ehcache 的读取大型 CSV 文件并缓存到临时文件中的示例代码：

import org.ehcache.Cache;
import org.ehcache.CacheManager;
import org.ehcache.config.builders.CacheConfigurationBuilder;
import org.ehcache.config.builders.ResourcePoolsBuilder;
import org.ehcache.impl.config.persistence.CacheManagerPersistenceConfiguration;
import org.ehcache.impl.persistence.DefaultLocalPersistenceService;
import org.ehcache.persistence.PersistentStorageFactory;
import org.supercsv.cellprocessor.ParseBool;
import org.supercsv.cellprocessor.ParseDate;
import org.supercsv.cellprocessor.ParseInt;
import org.supercsv.cellprocessor.ParseLong;
import org.supercsv.cellprocessor.ParseBigDecimal;
import org.supercsv.cellprocessor.Optional;
import org.supercsv.cellprocessor.constraint.NotNull;
import org.supercsv.cellprocessor.ift.CellProcessor;
import org.supercsv.io.CsvBeanReader;
import org.supercsv.io.ICsvBeanReader;
import org.supercsv.prefs.CsvPreference;

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class CsvCacheDemo {

    private static final String CACHE_NAME = "csv-cache";
    private static final String CACHE_PATH = "temp/cache";
    private static final String CSV_PATH = "data.csv";

    public static void main(String[] args) throws IOException {
        // 创建缓存管理器
        CacheManager cacheManager = createCacheManager();

        // 从缓存获取数据，如果缓存不存在则从 CSV 文件读取并缓存
        List<DemoDto> demoList = readFromCache(cacheManager);

        // 打印结果
        demoList.forEach(System.out::println);

        // 关闭缓存管理器
        cacheManager.close();
    }

    private static CacheManager createCacheManager() {
        // 创建本地持久化服务
        DefaultLocalPersistenceService persistenceService = new DefaultLocalPersistenceService(
                new CacheManagerPersistenceConfiguration(new File(CACHE_PATH)));

        // 创建缓存管理器
        return CacheManagerBuilder.newCacheManagerBuilder()
                .using(persistenceService)
                .withCache(CACHE_NAME, CacheConfigurationBuilder.newCacheConfigurationBuilder(
                        String.class, List.class, ResourcePoolsBuilder.heap(1))
                        .withExpiry(Expirations.timeToLiveExpiration(Duration.ofMinutes(10))))
                .build(true);
    }

    private static List<DemoDto> readFromCache(CacheManager cacheManager) throws IOException {
        // 获取或创建缓存
        Cache<String, List<DemoDto>> cache = cacheManager.getCache(CACHE_NAME, String.class, List.class);

        // 尝试从缓存读取数据
        String key = CSV_PATH;
        List<DemoDto> demoList = cache.get(key);

        if (demoList == null) {
            // 缓存不存在，从 CSV 文件读取并缓存
            demoList = readFromCsv();
            cache.put(key, demoList);
        }

        return demoList;
    }

    private static List<DemoDto> readFromCsv() throws IOException {
        // 创建 CSV 读取器
        FileReader fileReader = new FileReader(CSV_PATH);
        ICsvBeanReader beanReader = new CsvBeanReader(fileReader, CsvPreference.STANDARD_PREFERENCE);

        // 定义 CSV 列名和属性映射关系
        final String[] header = beanReader.getHeader(true);
        final CellProcessor[] processors = new CellProcessor[] {
                new NotNull(), new ParseLong(), new Optional(new ParseInt()), new Optional(new ParseBigDecimal()),
                new Optional(new ParseDate("yyyy-MM-dd")), new Optional(new ParseBool())};

        // 读取 CSV 数据并转换为 DTO 对象
        List<DemoDto> demoList = new ArrayList<>();
        DemoDto demoDto;
        while ((demoDto = beanReader.read(DemoDto.class, header, processors)) != null) {
            demoList.add(demoDto);
        }

        // 关闭 CSV 读取器
        beanReader.close();

        // 将数据写入临时文件
        File tempFile = File.createTempFile("csv-cache", ".tmp");
        FileWriter fileWriter = new FileWriter(tempFile);
        tempFile.deleteOnExit();
        for (DemoDto dto : demoList) {
            fileWriter.write(dto.toString());
            fileWriter.write(System.lineSeparator());
        }
        fileWriter.close();

        return demoList;
    }

    public static class DemoDto {
        private String name;
        private long id;
        private Integer age;
        private BigDecimal amount;
        private Date date;
        private Boolean flag;

        // getter 和 setter 省略
    }
}

此示例代码使用 Ehcache 缓存管理器和本地持久化服务，将读取的 CSV 数据缓存到 `temp/cache` 目录下的临时文件中，并以 `List<DemoDto>` 的形式返回给调用方。如果缓存中存在数据，则直接从缓存中读取；否则从 CSV 文件读取并缓存到缓存和临时文件中。