我有一个存储在 URL 上的 XML。我正在从我的 Android 应用程序中解析该 URL。让网址为
http://www.w3schools.com/xpath/books.xml
我想使用 XPath 遍历一些节点并显示结果。但是当我阅读教程时,我开始知道 XML 文件必须存储在项目中。我的意思是这样的:
Document document = builder.parse(new File("/books.xml"));
如果我提供 XML 文件的 URL 即http://www.w3schools.com/xpath/books.xml而不是先保存文件然后使用它,XPath 可以工作吗?
编辑:这是代码:
public class MainActivity extends ListActivity {
// data
ArrayList<String> mPeople = new ArrayList<String>();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try {
parseData();
} catch(Exception ex) {
Toast.makeText(this, "Exception: " + ex.getMessage(), Toast.LENGTH_LONG).show();
}
// pass adapter w/ data queried through XPath to ListView
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mPeople);
setListAdapter(adapter);
}
private void parseData() throws Exception {
// create an InputSource object from /res/raw
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(new URL("http://www.w3schools.com/xpath/books.xml").openConnection().getInputStream());
doc.getDocumentElement().normalize();
// query XPath instance, this is the parser
XPath xpath = XPathFactory.newInstance().newXPath();
// specify the xpath expression
String expression = " /bookstore/book/title ";
// list of nodes queried
NodeList nodes = (NodeList)xpath.evaluate(expression, doc, XPathConstants.NODESET);
Toast.makeText(this, "count: " + String.valueOf(nodes.getLength()),Toast.LENGTH_SHORT).show();
// if node found
if(nodes != null && nodes.getLength() > 0) {
mPeople.clear();
int len = nodes.getLength();
for(int i = 0; i < len; ++i) {
// query value
Node node = nodes.item(i);
mPeople.add(node.getTextContent());
}
}
}
任何帮助将不胜感激。