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发表于 更新于 分类于 阅读次数： Valine：
本文字数： 1.4k 阅读时长 ≈ 1 分钟

POI操作EXCEL增加下拉框

依赖

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<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.2</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>

有时候通过excel将数据批量导入到系统，而业务操作人员对于一些列不想手动输入，而是采用下拉框的方式来进行选择

image-20230324161922014

采用隐藏sheet页的方式来进行操作

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String sheetName = "supplier_hidden_sheet";

HSSFSheet supplierSheet = workbook.createSheet(sheetName);//隐藏的sheet,用于存放下拉框的限定值
int count = 0;
for(String supplierName : suppliers){
    supplierSheet.createRow(count++).createCell(0).setCellValue(supplierName);
}
      
String col = "A";

//设置数据有效性加载在哪个单元格上,四个参数分别是：起始行、终止行、起始列、终止列
CellRangeAddressList regions = new CellRangeAddressList(1, dataList.size(), supplierColumn, supplierColumn);
// 这是表示从隐藏sheet页的哪列哪行到哪列哪行  如该格式 supplier_hidden_sheet!$A$1:$A$73 
String cell = "\""+sheetName +"!$"+col+"$1:$"+col+"$"+suppliers.size()+"\"";
// 引用ShtDictionary 的单元格
DVConstraint constraint = DVConstraint.createFormulaListConstraint("INDIRECT("+cell+ ")");
// 数据检验为该格式  =INDIRECT("supplier_hidden_sheet!$A$1:$A$73")
HSSFDataValidation dataValidate = new HSSFDataValidation(regions, constraint);
sheet.addValidationData(dataValidate);
workbook.setSheetHidden(1,true);

可以在EXCEL中的数据有效性看到数据来源

image-20230324162821672

发表于 更新于 分类于 阅读次数： Valine：
本文字数： 1.2k 阅读时长 ≈ 1 分钟

xuggle操作视频

有个需求是要读取视频的宽高，找到了Xuggle和FFmpeg两种方式，FFmpeg很强大，但是我并不需要那些功能，所以使用了轻量一点的Xuggle

引入依赖

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<dependency>
    <groupId>xuggle</groupId>
    <artifactId>xuggle-xuggler</artifactId>
    <version>5.4</version>
</dependency>

可能maven仓库中没有该依赖，可以下载后放到本地仓库或私服

xuggle-xuggler-5.4.jar

操作示例

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String fileName = "/Users/zhanghe/Desktop/1.mp4";
IContainer container = IContainer.make();
IContainerFormat format = IContainerFormat.make();

int result = container.open(fileName, IContainer.Type.READ, null);
if(result < 0){
    throw new RuntimeException("不能打开该文件");
}
int num = container.getNumStreams();
for(int i = 0;i<num;i++){
    IStream stream = container.getStream(i);
    IStreamCoder coder = stream.getStreamCoder();
    if(coder.getCodecType() == ICodec.Type.CODEC_TYPE_VIDEO){
        System.out.println(coder.getWidth());
        System.out.println(coder.getHeight());
    }

}

// 还可以获取
// 时长 单位是μs
long duration = container.getDuration();
System.out.println("duration:"+duration);
// 文件大小
long fileSize = container.getFileSize();
System.out.println("fileSize:"+fileSize);
// 码率
int bitRate = container.getBitRate();
System.out.println("bitRate:"+bitRate);

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服务获取和服务续约

eureka客户端通过定时任务的方式进行服务获取和服务续约，在com.netflix.discovery.DiscoveryClient类中，启动了两个定时任务来进行处理

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private void initScheduledTasks() {
  // 是否需要拉取
    if (clientConfig.shouldFetchRegistry()) {
        // registry cache refresh timer
        int registryFetchIntervalSeconds = clientConfig.getRegistryFetchIntervalSeconds();
        int expBackOffBound = clientConfig.getCacheRefreshExecutorExponentialBackOffBound();
      // 拉取的定时任务时间间隔是registryFetchIntervalSeconds
        scheduler.schedule(
                new TimedSupervisorTask(
                        "cacheRefresh",
                        scheduler,
                        cacheRefreshExecutor,
                        registryFetchIntervalSeconds,
                        TimeUnit.SECONDS,
                        expBackOffBound,
                        new CacheRefreshThread()
                ),
                registryFetchIntervalSeconds, TimeUnit.SECONDS);
    }
// 是否需要注册
    if (clientConfig.shouldRegisterWithEureka()) {
        int renewalIntervalInSecs = instanceInfo.getLeaseInfo().getRenewalIntervalInSecs();
        int expBackOffBound = clientConfig.getHeartbeatExecutorExponentialBackOffBound();
        logger.info("Starting heartbeat executor: " + "renew interval is: {}", renewalIntervalInSecs);

        // Heartbeat timer
        scheduler.schedule(
                new TimedSupervisorTask(
                        "heartbeat",
                        scheduler,
                        heartbeatExecutor,
                        renewalIntervalInSecs,
                        TimeUnit.SECONDS,
                        expBackOffBound,
                        new HeartbeatThread()
                ),
                renewalIntervalInSecs, TimeUnit.SECONDS);

        // InstanceInfo replicator
        instanceInfoReplicator = new InstanceInfoReplicator(
                this,
                instanceInfo,
                clientConfig.getInstanceInfoReplicationIntervalSeconds(),
                2); // burstSize

        statusChangeListener = new ApplicationInfoManager.StatusChangeListener() {
            @Override
            public String getId() {
                return "statusChangeListener";
            }

            @Override
            public void notify(StatusChangeEvent statusChangeEvent) {
                if (InstanceStatus.DOWN == statusChangeEvent.getStatus() ||
                        InstanceStatus.DOWN == statusChangeEvent.getPreviousStatus()) {
                    // log at warn level if DOWN was involved
                    logger.warn("Saw local status change event {}", statusChangeEvent);
                } else {
                    logger.info("Saw local status change event {}", statusChangeEvent);
                }
                instanceInfoReplicator.onDemandUpdate();
            }
        };

        if (clientConfig.shouldOnDemandUpdateStatusChange()) {
            applicationInfoManager.registerStatusChangeListener(statusChangeListener);
        }

        instanceInfoReplicator.start(clientConfig.getInitialInstanceInfoReplicationIntervalSeconds());
    } else {
        logger.info("Not registering with Eureka server per configuration");
    }
}

来分别看一下两个定时逻辑

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