java - 异常说明 "Resetting to invalid mark "在标记 inputStream 并重置它时出现，对于大文件。？

Question

我正在使用 InputStream 对象来计算某个文件的 Md5。我标记流后来我重置了流。但是，对于大文件，会出现以下异常...

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

异常

.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)

---

我试过关闭流并以这种方式重新打开它..只是为了得到一些异常如下::

 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

我假设您正在使用 BufferedInputStream，因为它的 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;
}

下面的调用

MD5CheckSumCalculator.calculateMD5CheckSum(inStreamLatestFile);

必须对 markPos 做些什么。

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

您可以将原始的 InputStream 读取到 ByteArrayOutputStream 中。将该流中的字节复制到新的 ByteArrayInputStream 中。将其传递给 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任何其他内容。