我试图从 url 的 xml 标记名中检索内容,但我的 int numberOfDetails 的长度为 0。我做错了什么?
//编辑后的代码
public String[] dumpTitles(String[] xmlFiles) {
String[] elementsArray = null;
try {
URL xmlContent = new URL("http://webdev4.matcmadison.edu/mab/AmazonXML/georgeEliot.xml");
DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = db.parse(new InputSource(xmlContent.openStream()));
Toast.makeText(this, "xml file: " + xmlContent, 1000).show();
NodeList detailsNodeList = doc.getElementsByTagName("Details");
int numberOfDetails = detailsNodeList.getLength();
String str = String.format("There are %d Details elements", numberOfDetails);
Log.println(Log.DEBUG, TAG, str);
Toast.makeText(this, "number of details: " + str, 1000).show();
elementsArray = getElementByTagName("ProductName", numberOfDetails, detailsNodeList);
}
catch (Exception ex) {
Log.println(Log.DEBUG, TAG, "XML Parsing failed: " + ex.getMessage());
}
return elementsArray;
}
public String[] getElementByTagName(String detailTagName, int numberOfDetails, NodeList detailsNodeList) throws Exception {
String[] elementsArray = null;
ArrayList<String> elementsArrayList = new ArrayList<String>();
Toast.makeText(this, "TEST2", 1000).show();
for (int k = 0; k < numberOfDetails; k++) {
Toast.makeText(this, "TEST3", 1000).show();
Element nDetails = (Element)detailsNodeList.item(k);
NodeList elementNodeList = ((Document) nDetails).getElementsByTagName(detailTagName);
Node nodeName = elementNodeList.item(k);
String nodeString = String.format("%s", nodeName);
elementsArrayList.add(nodeString);
elementsArray = elementsArrayList.toArray(elementsArray);
Log.println(Log.DEBUG, TAG, nodeString);
Toast.makeText(this, "TEST4", 1000).show();
Toast.makeText(this, "ELEMENT" + elementsArray[0], 1000).show();
}
return elementsArray;
}
//原始代码 字符串 xmlContent = "http://webdev4.matcmadison.edu/mab/AmazonXML/georgeEliot.xml"; Log.println(Log.DEBUG, TAG, "文件名:"+ xmlContent); String[] elementsArray = null; 尝试 { DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder(); Toast.makeText(this, "xml 文件:"+ xmlContent, 1000).show(); 文档 doc = db.parse(new InputSource(new StringReader(xmlContent))); NodeList 详细信息NodeList = doc.getElementsByTagName("详细信息"); int numberOfDetails = detailsNodeList.getLength();
最佳答案
您不应该使用StringReader
从url读取。 StringReader
读取您在构造函数中传递的字符串,它不会从网络下载文件。您可以使用 URL
类来代替:
URL xmlContent = new URL("http://webdev4.matcmadison.edu/mab/AmazonXML/georgeEliot.xml");
DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = db.parse(new InputSource(xmlContent.openStream()));
另一种方式:
您可以使用constructor的InputSource
,它采用String
:
String pathToDocument = "http://webdev4.matcmadison.edu/mab/AmazonXML/georgeEliot.xml";
Document doc = db.parse(new InputSource(pathToDocument));
关于java - 在 Java 中从 URL 解析 XML 标记名,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/8021428/