多线程程序

private final ThreadPoolExecutor pool;

pool = new BlockedThreadPoolExecutor(maxThreads,
                maxThreads,
                1, TimeUnit.DAYS,
                new ArrayBlockingQueue(maxThreads),
                new CustomNameThreadFactory("FaceBaseClient"));

futures.add(pool.submit(new ImportTask(index++, url, user, passwd,
                                                       this.getFetchSql(startRyid),batch,
                                                       faceBaseName, metrics, conf)));

public Integer call() {
     int total = 0;
        Connection con = null;
        Statement stmt = null;

        System.out.println("Import job '" + index + "' is starting...");

        FaceBaseClient client = null;
        try{
            this.metrics.incrementTaskCount();
            client = new FaceBaseClient(conf);
            Class.forName("oracle.jdbc.driver.OracleDriver");
            con = DriverManager.getConnection(url, user, passwd);

            System.out.println("TaskID=" + index + ", connect db...");
            stmt = con.createStatement();

            System.out.println("TaskID=" + index + ", query: " + sql);
            ResultSet results = stmt.executeQuery(sql);
            List<FaceRecord> records = new ArrayList<FaceRecord>();
            while(results.next()){

                try{
                    records.add(resultSet2FaceRecord(results));
                }catch (SQLException e1){
                 System.out.println("TaskID=" + index + ", Exception:" + e1.getMessage() + ", continue..");
                }

                if(records.size() >= this.batch){
                    client.updateFaceRecords(faceBaseName, records, false);
                    this.metrics.addAndGet(records.size());
                    records.clear();
                }
                total++;
            }

            if(records.size() > 0){
                client.insertFaceRecords(faceBaseName, records);
                this.metrics.addAndGet(records.size());
                records.clear();
            }
        }catch (Exception e){
         System.out.println("TaskID=" + index + ", Exception:" + e.getMessage());
            e.printStackTrace();
        } finally {
            if(con != null){
                try {
                    con.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }

            if(client != null){
                client.cleanup();
            }
        }

        this.metrics.incrementFinishedTaskCount();
        return total;
    }