我在youtube上按照教程添加解析到Android应用程序。在他的教程中，他解析了一个永远不会在http://demoprojectserver1234.appspot.com/xmlquery.cgi?appid=3fa19507-c746-4dfa-8ded-ec60ef4d30d9关闭的记录标记内的数据。我想将此应用于我的项目并解析一些谷歌地图API。来自该网址的http://maps.googleapis.com/maps/api/distancematrix/xml?origins=Denver&destinations=Miami&language=en-EN&sensor=false我想修改教程以捕获持续时间文本标记1天5小时的值以及距离文本标记3,317 km。
这是我完成教程后的主要活动课程。我知道我需要在processReceivedData方法中更改if（tagName.equals（＆＃34; record＆＃34;）to something，但我不确定我是否会使用持续时间或文本，而且我不确定我是否愿意制作第二个if（tagName.equals（＆＃34; record＆＃34;）来捕获远处/文本或者如果我使用了文本，我可以让它成为一个循环来抓取它们。任何帮助都指向我正确收集我所追求的价值观的方向将不胜感激。
public class MainActivity extends Activity implements OnClickListener {
private static final String TAG = "ProjectServerDemo";
Button destination_next_button;
public final static String START_LOCATION = "com.google.gascalculator.START_LOCATION";
public final static String END_LOCATION = "com.google.gascalculator.END_LOCATION";
public static final String QUERY_URL = "http://maps.googleapis.com/maps/api/distancematrix/xml?origins="
+ START_LOCATION + "&destinations=" + END_LOCATION
+ "&language=en-EN&sensor=false";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
destination_next_button = (Button) findViewById(R.id.destination_next_button);
destination_next_button.setOnClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
private void destination_next_buttonClick() {
Intent intent = new Intent(MainActivity.this, Vehicle.class);
EditText startText = (EditText) findViewById(R.id.startinglocation);
EditText endText = (EditText) findViewById(R.id.endinglocation);
String startDestination = startText.getText().toString();
String endDestination = endText.getText().toString();
intent.putExtra(START_LOCATION, startDestination);
intent.putExtra(END_LOCATION, endDestination);
startActivity(intent);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.destination_next_button:
destination_next_buttonClick();
AsyncDownloader downloader = new AsyncDownloader();
downloader.execute();
break;
}
}
private void handleNewRecord(String itemId, String data) {
TextView textView = (TextView) findViewById(R.id.informationTextView);
String message =
textView.getText().toString() + "\n" +
itemId + ": " + data;
textView.setText("");
}
private class AsyncDownloader extends AsyncTask<Object, String, Integer> {
@Override
protected Integer doInBackground(Object... arg0) {
XmlPullParser receivedData = tryDownloadingXmlData();
int recordsFound = tryParsingXMLData(receivedData);
return recordsFound;
}
private XmlPullParser tryDownloadingXmlData() {
try {
URL xmlUrl = new URL(QUERY_URL);
XmlPullParser receivedData = XmlPullParserFactory.newInstance().newPullParser();
receivedData.setInput(xmlUrl.openStream(), null);
return receivedData;
} catch (XmlPullParserException e) {
} catch (IOException e) {
}
return null;
}
private int tryParsingXMLData(XmlPullParser receivedData) {
if (receivedData != null) {
try {
return processReceivedData(receivedData);
} catch (XmlPullParserException e) {
} catch (IOException e) {
}
}
return 0;
}
private int processReceivedData(XmlPullParser xmlData) throws XmlPullParserException, IOException {
int recordsFound = 0;
//find values in the xml records
String appId = "";
String itemId = "";
String timeStamp = "";
String data = "";
int eventType = -1;
while (eventType != XmlResourceParser.END_DOCUMENT) {
String tagName = xmlData.getName();
switch (eventType) {
case XmlResourceParser.START_TAG:
//start of a record so pull values encoded as attributes
if (tagName.equals("record")) {
appId = xmlData.getAttributeValue(null, "appid");
itemId = xmlData.getAttributeValue(null, "itemid");
timeStamp = xmlData.getAttributeValue(null, "timestamp");
data = "";
}
break;
//Grab data text (simple processing)
//Note this could be full xml data to process
case XmlResourceParser.TEXT:
data += xmlData.getText();
break;
case XmlPullParser.END_TAG:
if (tagName.equals("record")) {
recordsFound++;
publishProgress(appId, itemId, data, timeStamp);
}
break;
}
eventType = xmlData.next();
}
//handle no data available publish an empty event.
if (recordsFound == 0) {
publishProgress();
}
return 0;
}
@Override
protected void onProgressUpdate(String... values) {
if (values.length == 4) {
String appId = values[0];
String itemId = values[1];
String data = values[2];
String timestamp = values[3];
handleNewRecord(itemId, data);
}
super.onProgressUpdate(values);
}
}
}
答案 0 :(得分：0)
您希望存储当前所在的节点，以便可以编写“如果当前节点为row.element.duration.value，则将文本解析为持续时间值”。
你可以这样做：
private StringBuilder path = new StringBuilder();
// (...)
case XmlResourceParser.START_TAG:
path.append('.').append(tagName);
case XmlResourceParser.TEXT:
String node = path.toString();
if ("DistanceMatrixResponse.row.element.duration.value".equals(node) {
// parse duration value
} else if ("DistanceMatrixResponse.row.element.distance.value".equals(node) {
// parse distance value
} // etc...
case XmlResourceParser.END_TAG:
path.setLength(path.length() - tagName.length()); // remove tag name
if (path.length() > 0)
path.setLength(path.length() - 1); // remove trailing '.'