Callable 或Runable实现类自定义内部类也可以；

 //ExecutorService service = Executors.newFixedThreadPool(8);
 ExecutorService service = Executors.newCachedThreadPool(); 

 
        Future<String> result1 = service.submit(new Callable<String>() {
            @Override
            public String call() throws Exception {
                Thread.sleep(3000);
                return "s1";
            }
        });
 
        Future<String> result2 = service.submit(new Callable<String>() {
            @Override
            public String call() throws Exception {
                Thread.sleep(3000);
                return "s2";
            }
        });
 
        Future<String> result3 = service.submit(new Callable<String>() {
            @Override
            public String call() throws Exception {
                Thread.sleep(3000);
                return "s3";
            }
        });
 
        System.out.println(result1.get());
        System.out.println(result2.get());
        System.out.println(result3.get());
 
        //service.shutdown();


或者下面内部类：

package com.realize.market.value.service;

import com.realize.market.value.domain.vos.DownloadReportSearchVo;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.Callable;


/**
 * 内部多线程任务类-查询所有模块echart 图形数据和文字描述
 */
public class MyEchartDataQueryTaskCallable implements Callable<Map> {
    private Integer taskNum;
    private Integer userId;
    private String secCode;
    private DownloadReportSearchVo downloadReportSearchVo;
    private IDownloadReportService downloadReportService;

    public MyEchartDataQueryTaskCallable(Integer taskNum, Integer userId, String secCode, DownloadReportSearchVo downloadReportSearchVo, IDownloadReportService downloadReportService) {
        this.taskNum = taskNum;
        this.userId = userId;
        this.secCode = secCode;
        this.downloadReportSearchVo = downloadReportSearchVo;
        this.downloadReportService = downloadReportService;
    }

    @Override
    public Map call() throws Exception {
        System.out.println(">>>" + taskNum + "任务启动");
        Date dateTmp1 = new Date();
        //多线程处理耗时较久的查询各个模块方法；
        Map<String, Object> wordInitDataMaps = new HashMap<>();

        switch (taskNum) {
            case 1://1-1 诊断结果 > 市值表现
                wordInitDataMaps = downloadReportService.exportToWord_11(userId, secCode);
                break;
            case 2://1-2 诊断结果 > 流动性情况
                wordInitDataMaps = downloadReportService.exportToWord_12(userId, secCode);
                break;
            case 3://1-3 诊断结果 > 股东结构分析
                wordInitDataMaps = downloadReportService.exportToWord_13(userId, secCode);
                break;
            case 4://2-1 市值表现 > 市值对比
                wordInitDataMaps = downloadReportService.exportToWord_21(userId, secCode, downloadReportSearchVo);
                break;
            case 5://2-2 市值表现 > 估值对比
                wordInitDataMaps = downloadReportService.exportToWord_22(userId, secCode, downloadReportSearchVo);
                break;
            case 6://2-3 市值表现 > 股价对比
                wordInitDataMaps = downloadReportService.exportToWord_23(userId, secCode, downloadReportSearchVo);
                break;
            case 7://3-1 流动性表现 > 换手率
                wordInitDataMaps = downloadReportService.exportToWord_31(userId, secCode, downloadReportSearchVo);
                break;
            case 8://3-2 流动性表现 > 流动比
                wordInitDataMaps = downloadReportService.exportToWord_32(userId, secCode, downloadReportSearchVo);
                break;
            case 9://4-1 股东结构统计 > 股东户数统计
                wordInitDataMaps = downloadReportService.exportToWord_41(userId, secCode, downloadReportSearchVo);
                break;
            case 10://4-2 股东结构统计 > 户均持股市值
                wordInitDataMaps = downloadReportService.exportToWord_42(userId, secCode, downloadReportSearchVo);
                break;
            case 11://4-3 股东结构统计 > 前10名股东持股情况
                wordInitDataMaps = downloadReportService.exportToWord_43(userId, secCode, downloadReportSearchVo);
                break;
            case 12://4-4 股东结构统计 > 机构投资者情况
                wordInitDataMaps = downloadReportService.exportToWord_44(userId, secCode, downloadReportSearchVo);
                break;
            case 13://2-1 市值表现 > 市值涨跌幅
                wordInitDataMaps = downloadReportService.exportToWord_24(userId, secCode, downloadReportSearchVo);
                break;
            case 14://2-1 市值表现 > 市场市值对比
                wordInitDataMaps = downloadReportService.exportToWord_25();
                break;
        }
        Date dateTmp2 = new Date();
        long time = dateTmp2.getTime() - dateTmp1.getTime();
        System.out.println(taskNum + "任务终止" + ">>>单个任务耗时：" + time);
        return wordInitDataMaps;
    }
}