对于大文件，在标记inputStream并将其重置时会出现异常，说明“重置为无效标记”。

Question

我正在使用InputStream对象来计算某些文件的Md5。我标记了流，稍后重置流。但是，对于大文件，将出现以下异常...

inStreamLatestFile.mark(0);
checkSumCalculated = MD5CheckSumCalculator.calculateMD5CheckSum(inStreamLatestFile);
inStreamLatestFile.reset();

例外

.Md5ValidationAggrStrat ||**Error in calculating checksum:: java.io.IOException: Resetting to invalid mark**
                        ||java.io.IOException: Resetting to invalid mark
                        ||at java.io.BufferedInputStream.reset(BufferedInputStream.java:437)
                        ||at com.amadeus.apt.ib.modules.func.map.camel.strategy.Md5ValidationAggrStrategy.aggregate(Md5ValidationAggrStrategy.java:81)
                        ||at org.apache.camel.processor.aggregate.AggregateProcessor.onAggregation(AggregateProcessor.java:365)
                        ||at org.apache.camel.processor.aggregate.AggregateProcessor.doAggregation(AggregateProcessor.java:245)
                        ||at org.apache.camel.processor.aggregate.AggregateProcessor.process(AggregateProcessor.java:201)
                        ||at org.apache.camel.util.AsyncProcessorConverterHelper$ProcessorToAsyncProcessorBridge.process(AsyncProcessorConverterHelper.java:61)
                        ||at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:73)

---

我试图关闭流并以这种方式重新打开它。.只是为了获得一些异常，如下所示：

 try {
        inStreamLatestFile= ExchangeHelper.getMandatoryInBody(
                  oldExchange, InputStream.class);

        //inStreamLatestFile.mark(0);
        checkSumCalculated = MD5CheckSumCalculator.calculateMD5CheckSum(inStreamLatestFile);

        //closing the inputStream of the latest file
        if(inStreamLatestFile != null){
            try {
                inStreamLatestFile.close();
            } catch (IOException e) {
                logger.error("Error occurred in closing the stream :: "+ e.getMessage());
            }
        }


        tempInputStream= ExchangeHelper.getMandatoryInBody(
                  oldExchange, InputStream.class);
        oldExchange.getIn().setBody(tempInputStream);

但是，当我尝试重新使用新检索的InputStream时，出现以下异常。

 caught: java.io.IOException: Stream closed: java.io.IOException: Stream closed
at java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:162)

Answer 1

我将假设您正在使用 aBufferedInputStream因为它的reset()方法源代码是

public synchronized void reset() throws IOException {
    getBufIfOpen(); // Cause exception if closed
    if (markpos < 0)
        throw new IOException("Resetting to invalid mark"); // exception you are getting
    pos = markpos;
}

下面的调用

MD5CheckSumCalculator.calculateMD5CheckSum(inStreamLatestFile);

一定是对markPos.

如果您无法控制它，只需重新打开流。如果您无法重新打开流，即。您每次都检索相同的实例，请考虑使用ByteArrayOutputStream

您可以将原件读InputStream入ByteArrayOutputStream. 将该流中的字节复制到一个新的ByteArrayInputStream. 将其传递给 MD5 计算器。然后ByteArrayInputStream使用相同的字节再次创建一个新的并将其传递给您需要的任何其他内容。