Using multithreaded callable to query Oracle Database

Use single threaded queries 10 Ten thousand data are too slow , Use multithreading to query , Increase of efficiency .

ThredQuery Method of querying data

public class ThredQuery implements Callable<List<HashVO>> {
    


    private MyUtil util = new MyUtil();

    private int bindex;// The current number of pages 

    private int num;// How many queries per page 


    private List page;// The data found in each page 
    private String customerName;
    private String customerType;
    private String idType;
    private String idNumb;
    private String updateTime;

    public  ThredQuery(int bindex,int num,String customerName, String customerType, String idType, String idNumb, String updateTime) {
    
        this.bindex=bindex;
        this.num=num;
        this.customerName=customerName;
        this.customerType=customerType;
        this.idType=idType;
        this.idNumb=idNumb;
        this.updateTime=updateTime;
    }


    @Override
    public List<HashVO> call() throws Exception {
    
        String sql = "";

        if (StringUtils.isNotBlank(customerName)) {
    
            sql += " and customer_name like '%" + customerName + "%' ";
        }
        if (StringUtils.isNotBlank(customerType)) {
    
            sql += " and customer_type = '" + customerType + "' ";
        }
        if (StringUtils.isNotBlank(idType)) {
    
            sql += " and id_type = '" + idType + "' ";
        }
        if (StringUtils.isNotBlank(idNumb)) {
    
            sql += " and id_numb like '%" + idNumb + "%' ";
        }
        if (StringUtils.isNotBlank(updateTime)) {
    
            sql += " and (" + updateTime + ")";
        }
        sql += " order by id";
        String finalSql = "SELECT * FROM " +
                "(" +
                "SELECT A.*, ROWNUM RN " +
                "FROM ("
                + sql +
                " ) A " +
                " WHERE ROWNUM <= "+ (bindex*num)+
                " ) " +
                "WHERE RN >= "+(((bindex-1)*num)+1);

        return Arrays.asList(util.getHashVOs(finalSql));
    }

}

Be careful ：call Inside is the query method .util Is to query data , perform sql

oracle Paging method , With pageIndex and pageSize For example

 String sql= "SELECT * FROM " +
                "(" +
                "SELECT A.*, ROWNUM RN " +
                "FROM ("
                + sql +
                " ) A " +
                " WHERE ROWNUM <= "+ (pageIndex*pageSize)+
                " ) " +
                "WHERE RN >= "+(((pageIndex-1)*pageSize)+1);

Calling method :

     private void  getVoListMultiThreading(String customerName, String customerType, String idType, String idNumb, String updateTime)  {
    
        long start = System.currentTimeMillis();// Starting time 
        List<HashVO> result = new ArrayList<>();// Return results 
        // Query the total number of databases 
        int count = queryCount();
        int num = 8000;// How many items are queried at a time 
        // Number of queries required 
        int times = count / num;
        if (count % num != 0) {
    
            times = times + 1;
        }
        // Start page number   The connection is orcle The database of   Encapsulated paging   Mine is from 1 Start 
        //Callable Used to produce results 
        List<Callable<List<HashVO>>> tasks = new ArrayList<>();
        for (int i = 1; i <= times; i++) {
    
            // Multithreaded query 
            Callable<List<HashVO>> qfe = new ThredQuery(i, num, customerName, customerType, idType, idNumb, updateTime);
            tasks.add(qfe);
        }
        // Define a fixed length thread pool   Prevent too many threads 
        ExecutorService executorService = Executors.newFixedThreadPool(15);

        //Future Used to get results 
        try {
    
            List<Future<List<HashVO>>> futures=executorService.invokeAll(tasks);
            // The processing thread returns the result 
            if(futures!=null&&futures.size()>0){
    
                for (Future<List<HashVO>> future:futures){
    
                    result.addAll(future.get());
                }
            }
        } catch (InterruptedException e) {
    
            throw new RuntimeException(e);
        } catch (ExecutionException e) {
    
            throw new RuntimeException(e);
        }
        executorService.shutdown();// Close thread pool 
        long end = System.currentTimeMillis();// End time 
        log.info(" Query time consuming ：" + (end - start) / 1000 + " second  "," result : "+result);
    }

Query time is only used 30s