从http服务器检索xml流- android问题

Question

在我的应用程序中，我必须从服务器获取一些分配的列表。在服务器上，我有一个方法，比如fetchAssignments(int,String)，它接受两个值作为参数。

1. 周期(今天、本月或本周)-整数
2. 用户id - String

函数以XML流的形式返回赋值列表。我知道如何连接到http服务器。但我不知道如何在服务器上调用该方法并将这些参数传递给它。有谁能给我一个更好的方法吗?

Answer 1

您可以使用HTTP GET请求从服务器请求XML作为InputStream，并将参数作为请求参数传递:

http://some.server/webapp?period=1&userid=user1

使用下面的方法，你可以从服务器获取流:

/**
 * Returns an InputStream to read from the given HTTP url.
 * @param url
 * @return InputStream
 * @throws IOException
 */
public InputStream get(final String url) throws IOException {
    HttpClient httpClient = new DefaultHttpClient();
    HttpParams httpParams = httpClient.getParams();
    HttpConnectionParams.setConnectionTimeout(httpParams, TIMEOUT);
    HttpConnectionParams.setSoTimeout(httpParams, TIMEOUT);
    HttpGet httpget = new HttpGet(url);
    HttpResponse httpResponse = httpClient.execute(httpget);
    StatusLine statusLine = httpResponse.getStatusLine();
    if(! statusLine.getReasonPhrase().equals("OK")) {
        throw new IOException(String.format("Request failed with %s", statusLine));
    }
    HttpEntity entity = httpResponse.getEntity();
    return entity.getContent();
}

然后可以使用"Simple"(http://simple.sourceforge.net/) XML库将XML解析为类似jaxb的实体:

/**
 * Reads the XML from the given InputStream using "Simple" and returns a list of assignments.
 * @param InputStream
 * @return List<Assignment>
 */
public List<Assignment> readSimple(final InputStream inputStream) throws Exception {
    Serializer serializer = new Persister();
    return serializer.read(AssignmentList.class, inputStream).getAssignments();     
}

我做的差不多，只是一个REST服务，所以我不使用请求参数

Answer 2

根据语言的不同，您可以通过URL HTTP请求或使用POST传递参数。在类的构造函数中(假设它是一个网页?. php ?.aspx?)检索这些值并将它们传递给上面提到的方法?

try{        
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.yoursite.com/getfeed.php");
InputSource inStream = new InputSource();
try {
// Add data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("period", period));
nameValuePairs.add(new BasicNameValuePair("userid", user_id));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
 // Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
HttpEntity r_entity = response.getEntity();
String xmlString = EntityUtils.toString(r_entity);
xmlString = xmlString.trim();
InputStream in = new ByteArrayInputStream(xmlString.getBytes("UTF-8"));
if(xmlString.length() != 0){
inStream.setByteStream(in);
PARSE_FLAG = true;
}
else
{
PARSE_FLAG = false;
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (IOException e) {
// TODO Auto-generated catch block
}