如何从Java中的URL读取XML响应？

Question

我需要编写一个简单的函数，该函数需要一个URL并处理XML或JSON响应，我已经检查了Sun网站https://swingx-ws.dev.java.net/servlets/ProjectDocumentList，但是HttpRequest对象是无处可寻，是否有可能在Java中做到这一点？我正在编写一个富客户端应用程序。

Answer 1

对于输入流的xml解析，您可以执行以下操作：

// the SAX way:

XMLReader myReader = XMLReaderFactory.createXMLReader();

myReader.setContentHandler(handler);

myReader.parse(new InputSource(new URL(url).openStream()));

// or if you prefer DOM:

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

DocumentBuilder db = dbf.newDocumentBuilder();

Document doc = db.parse(new URL(url).openStream());

但是为了通过HTTP从服务器与客户端进行通信，我更喜欢使用粗麻布库或springs HTTP invoker lib

Answer 2

如果要将XML直接打印到屏幕上，可以使用TransformerFactory

URL url = new URL(urlString);

URLConnection conn = url.openConnection();

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

DocumentBuilder builder = factory.newDocumentBuilder();

Document doc = builder.parse(conn.getInputStream());

TransformerFactory transformerFactory= TransformerFactory.newInstance();

Transformer xform = transformerFactory.newTransformer();

// that’s the default xform; use a stylesheet to get a real one

xform.transform(new DOMSource(doc), new StreamResult(System.out));