Question

我需要解析存储在blobstore中的XML文件。我该怎么做？

这是我到目前为止所做的事情：

FileService fileService = FileServiceFactory.getFileService();
AppEngineFile file = fileService.getBlobFile(new BlobKey(key));

我无法使用javax.xml包解析XML文件，或者我可以吗？如果付诸实施，该包中的类需要引用java.io.File对象。但我没有。

这就是我到目前为止所做的事情：（不是在服务器上，而是在本地）

         File blobKeys = new File("/home/non-admin/NetBeansProjects/Personal Site_Testers/web/xml/xml_1.xml");
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();
        Document doc = db.parse(blobKeys);
        Element root = doc.getDocumentElement();

        Element firstName = doc.createElement("first-name");
        firstName.setTextContent(name);

        root.appendChild(firstName);

        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer transformer = tf.newTransformer();
        DOMSource source = new DOMSource(doc);
        StreamResult result = new StreamResult(new File("/home/non-admin/NetBeansProjects/Personal Site_Testers/web/xml/xml_1.xml"));
        transformer.transform(source, result);

注意：有3个xml文件上传到blobstore。那些xml文件只有一个root标签。我想获取xml引用并解析它们以根据请求多次附加子节点。

Answer 1

如果你想解析* .xml，我认为jdom2可能更方便我在app引擎中使用它并且它可以工作。

但是，您可以阅读FileService API文档，并且有一个如何读取和写入文件的示例。如果你可以获得一个InputStream或Reader，那么你可以使用javax.xml来解析InputStream或Reader中的xml内容。

    FileService fileService = FileServiceFactory.getFileService();
    AppEngineFile readableFile = new AppEngineFile("your_file_name");
    FileReadChannel readChannel = fileService.openReadChannel(readableFile,
            false);
    InputStream input = Channels.newInputStream(readChannel);

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();
    Document doc = db.parse(input);

    Element root = doc.getDocumentElement();

    Element firstName = doc.createElement("first-name");
    firstName.setTextContent("content");

    root.appendChild(firstName);
    // Now write
    GSFileOptionsBuilder optionsBuilder = new GSFileOptionsBuilder()
            .setBucket("mybucket").setKey("myfile")
            .setMimeType("text/html").setAcl("public_read")
            .addUserMetadata("myfield1", "my field value"); // change as
                                                            // your need
    AppEngineFile writableFile = fileService.createNewGSFile(optionsBuilder
            .build());
    FileWriteChannel writeChannel = fileService.openWriteChannel(
            writableFile, false);
    OutputStream output = Channels.newOutputStream(writeChannel);

    TransformerFactory tf = TransformerFactory.newInstance();
    Transformer transformer = tf.newTransformer();
    DOMSource source = new DOMSource(doc);
    transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
    transformer.setOutputProperty(OutputKeys.INDENT, "yes");
    StreamResult result = new StreamResult(output);
    transformer.transform(source, result);

如何解析存储在Google App Engine上的blobstore中的XML文件？

1 个答案: