自己挖的坑自己填--开发问题记录

if(param==null||"".equals(param.trim()){....}
if(!(param==null||"".equals(param.trim())){....}
//使用isBlank/isNotBlank代替上面代码，更有可读性
if (StringUtils.isBlank(chargeSchemeNew)) {....}
if (StringUtils.isNotBlank(chargeSchemeNew)) {....}

String  str ="30-九月-2020";
Date date = new SimpleDateFormat("ddd-MMM-yyyy").parse(str);
System.out.println(date);   
//====结果====
Wed Sep 30 00:00:00 CST 2020

//====或直接获取excel数据再进行是否是日期的判断和处理
public static String importByExcelForDate(Cell currentCell) {
    String currentCellValue = "";
    // 判断单元格数据是否是日期
    if ("yyyy/mm;@".equals(currentCell.getCellStyle().getDataFormatString())
            || "m/d/yy".equals(currentCell.getCellStyle().getDataFormatString())
            || "yy/m/d".equals(currentCell.getCellStyle().getDataFormatString())
            || "mm/dd/yy".equals(currentCell.getCellStyle().getDataFormatString())
            || "dd-mmm-yy".equals(currentCell.getCellStyle().getDataFormatString())
            || "yyyy/m/d".equals(currentCell.getCellStyle().getDataFormatString())) {
        if (DateUtil.isCellDateFormatted(currentCell)) {
            // 用于转化为日期格式
            Date d = currentCell.getDateCellValue();
            DateFormat formater = new SimpleDateFormat("yyyy-MM-dd");
            currentCellValue = formater.format(d);
        }
    } else {
        // 不是日期原值返回
        currentCellValue = currentCell.toString();
    }
    return currentCellValue;
}

public static Map<String,List> analyzeExcel(MultipartFile file, Integer sheetIndex, Integer startRow) {
    List<AppointmentListVo> dataList = new LinkedList<>();
    Workbook wb = ExcelUtil.createWorkBook(file);
    if (wb != null) {
        Sheet sheet = wb.getSheetAt(sheetIndex);
        //一共有多少行
        int maxRownum = sheet.getPhysicalNumberOfRows();
        Row currentRow = sheet.getRow(startRow);
        //一共有多少列
        int maxColnum = currentRow.getPhysicalNumberOfCells();
        for (int i = startRow; i < maxRownum ; i ++) {
            currentRow = sheet.getRow(i);
            AppointmentListVo vo=new AppointmentListVo();
            if (currentRow != null) {
                String cellData;
                for (int j = 0; j < maxColnum; j++) {
                    //
                    currentRow.getCell(j).setCellType(HSSFCell.CELL_TYPE_STRING);
                    cellData = importByExcelForDate(currentRow.getCell(j));
                    if (j==0){
                        vo.setShortFirmName(cellData);
                    }else if(j==1){
                        vo.setTrainClassName(cellData);
                    } else if (j==2){
                        vo.setMacTypeName(cellData);
                    } else if (j==3){
                        vo.setDisplayChs(cellData);
                    }else if (j==4){
                        vo.setBeginTime(cellData);
                    }else if (j==5){
                        vo.setEndTime(cellData);
                    }else if(j==6){
                        //cellData =cellData.substring(0,cellData.length()-2);
                        vo.setTotalTrainPersons(Integer.parseInt(cellData));
                    }
                }
                dataList.add(vo);
            } else {
                break;
            }
        }
    }
    Map<String,List> map = new HashMap<>();
    map.put("dataList",dataList);
    return map;
}

//解决消费者先启动，生产者后启动导致消费者为null的问题
@Configuration
public class DubboConfig {
    /**
     * 消费者配置不主动监督zookeeper服务
     *
     * @return
     */
    @Bean
    public ConsumerConfig consumerConfig() {
        ConsumerConfig consumerConfig = new ConsumerConfig();
        consumerConfig.setCheck(false);
        consumerConfig.setTimeout(40000);
        return consumerConfig;
    }
} 

  <select id="selectIdByCondition" resultType="string">
    SELECT id FROM tab WHERE
    begin_date &lt;= #{beginTimeDate} //等价小于等于<=
  </select>

select initcap(to_char('2021-03-10','dd/mon/yyyy','NLS_DATE_LANGUAGE=American') from dual;

/**
 * 模拟ThreadLocal内存泄露导致OOM
 * JVM启动参数 -Xms20M -Xmx20M -Xmn10M
 */
public static void main(String[] args) {
    // 是否调用remove方法
    boolean doRemove = false;
    // 加锁，让多个线程串行执行，避免多个线程同时占用内存导致的内存溢出问题
    Object lockObj = new Object();
    // 开启20个线程
    ExecutorService executorService = Executors.newFixedThreadPool(20);
    // 为了不重复使用线程，用Map标记一下已经已使用过的线程，
    Map<Long, Integer> threadIdMap = new ConcurrentHashMap<>();
    // 循环向线程变量中设置数据 1024 * 1024 = 1M
    for (int i = 0; i < 20; i++) {
        executorService.execute(() -> {
            synchronized (lockObj) {
                Integer num = threadIdMap.putIfAbsent(Thread.currentThread().getId(), 1);
                if (num == null) {
                    ThreadLocal<Byte[]> threadLocal = new ThreadLocal<>();
                    threadLocal.set(new Byte[1024 * 1024]);
                    if(doRemove) {
                        // 解决内存泄露关键
                        threadLocal.remove();
                    }
                    // 将threadLocal置为空引用，利于回收
                    threadLocal = null;
                    // 手工回收
                    System.gc();
                    try {
                        // 调用GC后不一定会马上回收
                        Thread.sleep(500);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }

                System.out.println(Thread.currentThread().getName());
            }
        });
    }
}

    public static void main(String[] args) throws IOException {
       String tempString = null;
       File file = new File("Emp_plan_20210110.bin");
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(new FileInputStream(file),"GB18030"));
        while((tempString = bufferedReader.readLine())!=null){
            byte[] bytes = tempString.getBytes("GB18030");
            System.out.println(bytes.length);
        }
    }