堆栈跟踪：

Question

我在关注视频教程的同时写了这篇文章。教程显示了同样的事情，但没有错误！

以下是代码：

public static void main(String[] args){

    DocumentBuilderFactory bf = DocumentBuilderFactory.newInstance();
    try {
        DocumentBuilder db = bf.newDocumentBuilder();

        //says input stream cannot be null
        Document d = db.parse(XmlReader.class.getResourceAsStream("XMLFile.xml")); 

        d.normalize();

当我运行程序时，它表示输入流对于语句指示语句不能为null，但是不是 null！。文件路径是正确的！有什么我想念的吗？是否存在eclipse或XML文件或其他问题？

堆栈跟踪：

Exception in thread "main" java.lang.IllegalArgumentException: InputStream cannot be null
at javax.xml.parsers.DocumentBuilder.parse(Unknown Source)
at io.XMLFileReading.main(XMLFileReading.java:27)

Answer 1

似乎使用 FileInputStream 可以完成这项工作（而不是XmlReader.class.getResourceAsStream（））。

    NSNumber *compression = [NSNumber numberWithLong:900000];

    AVAsset *videoAsset = [[AVURLAsset alloc] initWithURL:inputURL options:nil];

    AVAssetTrack *videoTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
    CGSize videoSize = videoTrack.naturalSize;
    NSDictionary *videoWriterCompressionSettings =  [NSDictionary dictionaryWithObjectsAndKeys:compression, AVVideoAverageBitRateKey, nil];
    NSDictionary *videoWriterSettings = [NSDictionary dictionaryWithObjectsAndKeys:AVVideoCodecH264,
                                         AVVideoCodecKey, videoWriterCompressionSettings,
                                         AVVideoCompressionPropertiesKey, [NSNumber numberWithFloat:videoSize.width],
                                         AVVideoWidthKey, [NSNumber numberWithFloat:videoSize.height],
                                         AVVideoHeightKey, nil];

    AVAssetWriterInput* videoWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoWriterSettings];

    videoWriterInput.expectsMediaDataInRealTime = YES;

    videoWriterInput.transform = videoTrack.preferredTransform;

    AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:outputURL fileType:AVFileTypeQuickTimeMovie error:nil];

    [videoWriter addInput:videoWriterInput];

在此处查看类似问题和接受的答案：Cannot work with XML file. InputStream is null

在Java中读取XML文件时出现非法参数异常

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1 个答案: