声明“重置为无效标记”的异常是在标记一个inputStream并为大文件重置它时出现的。？

Question

我使用InputStream对象来计算某个文件的Md5。我标记流，然后重新设置流。但是，对于大型文件，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)

我试着关闭溪流，然后用这样的方式重新打开它。为了得到一些例外，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，当我试图恢复新检索的InputStream时，会出现以下异常。

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

Answer 1

我假设您使用的是BufferedInputStream，因为它用于reset()方法的源代码是

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;
}

以下呼叫

MD5CheckSumCalculator.calculateMD5CheckSum(inStreamLatestFile);

一定是对markPos做了什么。

如果你无法控制它，就重新打开溪流。如果你不能重开这条小溪.每次都要检索同一个实例，请考虑使用ByteArrayOutputStream

您可以将原始InputStream读入ByteArrayOutputStream。将该流中的字节复制到新的ByteArrayInputStream中。把它传递给MD5计算器。然后，使用相同的字节再次创建一个新的ByteArrayInputStream，并将其传递给您需要的其他任何东西。