java多线程小结

前段时间需要编写一个关于统计人口不同年龄段的数量，因为数据量比较大，又是大表，所以接口需要改写成同时并行循环操作，其中用到了一个异步多线程FutureTask并行操作，具体的代码如下：

• controller 调用层

    public void qryPersonByAge(AreaCode areaCode,NewAreaCode newAreaCode, ModelMap modelMap){
        //处理接收实体类
        AreaCodeUtil.changeAreaCode(areaCode,newAreaCode);
        List<PersonAge> list = new ArrayList<PersonAge>();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
        Calendar calendar = Calendar.getInstance();
        //['0-7', '8-13', '14-25', '26-35', '36-45', '46-55', '56-65', '66-75', '>76'] 年龄分布
        calendar.setTime(new Date());
        String endAge1 = sdf.format(calendar.getTime());
        calendar.add(Calendar.YEAR, -7);
        String startAge1 = sdf.format(calendar.getTime());
        calendar.add(Calendar.YEAR,-6);
        String startAge2 = sdf.format(calendar.getTime());
        calendar.add(Calendar.YEAR,-12);
        String startAge3 = sdf.format(calendar.getTime());
        calendar.add(Calendar.YEAR,-10);
        String startAge4 = sdf.format(calendar.getTime());
        calendar.add(Calendar.YEAR,-10);
        String startAge5 = sdf.format(calendar.getTime());
        calendar.add(Calendar.YEAR,-10);
        String startAge6 = sdf.format(calendar.getTime());
        calendar.add(Calendar.YEAR,-10);
        String startAge7 = sdf.format(calendar.getTime());
        calendar.add(Calendar.YEAR,-10);
        String startAge8 = sdf.format(calendar.getTime());
        calendar.add(Calendar.YEAR,-100);
        String startAge9 = sdf.format(calendar.getTime());
        list.add(new PersonAge("0-7",startAge1,endAge1));
        list.add(new PersonAge("8-13",startAge2,startAge1));
        list.add(new PersonAge("14-25",startAge3,startAge2));
        list.add(new PersonAge("26-35",startAge4,startAge3));
        list.add(new PersonAge("36-45",startAge5,startAge4));
        list.add(new PersonAge("46-55",startAge6,startAge5));
        list.add(new PersonAge("56-65",startAge7,startAge6));
        list.add(new PersonAge("66-75",startAge8,startAge7));
        list.add(new PersonAge(">76",startAge9,startAge8));
        //不同年龄循环查询
        //String startAge,endAge,ageLabel;
        //Map<String,Object> map = new HashMap<String, Object>();
        List<Map<String, Object>> personAgeList = new ArrayList<Map<String, Object>>();
        /*for(int i =0;i<list.size();i++){
            startAge = list.get(i).getStartAge();
            endAge = list.get(i).getEndAge();
            ageLabel = list.get(i).getAgeLabel();
            map = peaceIndexService.qryPersonByAge(newAreaCode.getQxdm(),newAreaCode.getZjdm(),newAreaCode.getCsqdm(),startAge,endAge,ageLabel);
            personAgeList.add(map);
        }*/

        long st = System.currentTimeMillis();

        List<FutureTask<Map<String, Object>>> tasks = new ArrayList<FutureTask<Map<String, Object>>>();
        for(int i =0;i<list.size();i++){

            FutureTask<Map<String, Object>> task = new FutureTask<Map<String, Object>>(new StatTask(newAreaCode.getQxdm(), newAreaCode.getZjdm(), newAreaCode.getCsqdm(), list.get(i).getStartAge(), list.get(i).getEndAge(), list.get(i).getAgeLabel(), peaceIndexService));
            ThreadPools.getInstance().getPools().submit(task);
            tasks.add(task);

        }

        for (FutureTask<Map<String, Object>> t : tasks) {

            try {

                Map<String, Object> m = t.get();
                if (m == null || m.isEmpty()) {
                    continue;
                }

                personAgeList.add(m);

            } catch (Exception e) {
                logger.error("--- Failed to get Callable[Future], Caused by : ", e);
            }

        }

        logger.info("--- Cost Time : " + (System.currentTimeMillis() - st) + "ms");

        modelMap.addAttribute("personAgeList",personAgeList);
        logger.info("年龄人口分布：{}",personAgeList);

    }

• StartTask.java 类，多线程启动类

import java.util.Collections;
import java.util.Map;
import java.util.concurrent.Callable;
public class StartTask implements Callable<Map<String, Object>> {

    private PeaceIndexService peaceIndexService;

    private String areaCodeDc;
    private String areaCodeSt;
    private String areaCodeCt;
    private String startAge;
    private String endAge;
    private String ageLabel;

    public StartTask(String areaCodeDc, String areaCodeSt, String areaCodeCt, String startAge, String endAge, String ageLabel, PeaceIndexService peaceIndexService) {

        this.areaCodeDc = areaCodeDc;
        this.areaCodeSt = areaCodeSt;
        this.areaCodeCt = areaCodeCt;
        this.startAge = startAge;
        this.endAge = endAge;
        this.ageLabel = ageLabel;
        this.peaceIndexService = peaceIndexService;

    }

    @SuppressWarnings("unchecked")
    @Override
    public Map<String, Object> call() throws Exception {
        //包装调用单线程正常接口
        Map<String, Object> map = peaceIndexService.qryPersonByAge(areaCodeDc, areaCodeSt, areaCodeCt, startAge, endAge, ageLabel);
        return (Map<String, Object>) (map == null ? Collections.emptyMap() : map);

    }

}