public ListRecord ListRecords(string sPrefix,
string sset,
string sfrom,
string suntil,
ResumptionToken objToken,
ref Object objHandler)
{
int fail = 0;
Restart:
System.IO.Stream objStream;
ListRecord objList = new ListRecord();
Record objRecord;
ResumptionToken myToken;
string tmp = "";
System.Net.HttpWebRequest wr = null;
System.Xml.XmlTextReader rd = null;
if (sPrefix.Length==0)
{
sPrefix = "oai_dc";
}
if (objToken==null)
{
if (sset.Length!=0)
{
sset = "&set=" + sset;
}
if (sfrom.Length!=0)
{
sfrom = "&from=" + sfrom;
}
if (suntil.Length!=0)
{
suntil = "&until=" + suntil;
}
prequestURL = baseURL + "?verb=ListRecords&metadataPrefix=" + sPrefix + sset + sfrom + suntil;
}
else
{
//This is where we handle the resumptionToken - McCown
prequestURL = baseURL + "?verb=ListRecords&resumptionToken=" + objToken.resumptionToken;
}
//======================================================
// If you wanted to support additional metadata formats,
// you would just need to have additional handlers.
//======================================================
try
{
wr = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(prequestURL);
//wr.Headers.Add("Host:" + System.Net.Dns.GetHostName());
wr.UserAgent = cUserAgent + DateTime.Now.ToString();
if (this.Timeout <= 0) { this.Timeout = 100000; }
wr.Timeout = this.Timeout;
System.Net.WebResponse response = wr.GetResponse();
objStream = response.GetResponseStream();
System.IO.StreamReader reader = new System.IO.StreamReader(objStream);
prawXML = reader.ReadToEnd();
//System.Windows.Forms.MessageBox.Show(prawXML);
reader.Close();
response.Close();
rd = new System.Xml.XmlTextReader(prawXML, System.Xml.XmlNodeType.Document, null);
rd.Normalization = true;
}
catch (System.Net.WebException ee)
{
int sleepval = 3000;
fail++;
//System.Windows.Forms.MessageBox.Show(tt.ToString());
//System.Windows.Forms.MessageBox.Show(ee.ToString());
if (ee.Status == System.Net.WebExceptionStatus.ProtocolError)
{
var response = ee.Response as System.Net.HttpWebResponse;
if (response != null)
{
if ((int)response.StatusCode == 503)
{
string retryafter = response.Headers["Retry-After"];
if (retryafter != null && IsNumeric(retryafter) == true)
{
{
sleepval = System.Convert.ToInt32(retryafter) * 1000;
}
}
}
}
if (fail <= 4)
{
//System.Windows.Forms.MessageBox.Show(sleepval.ToString());
System.Threading.Thread.Sleep(sleepval);
goto Restart;
}
else
{
wr.Abort();
error.errorName = ee.ToString();
error.errorDescription = ee.Message + "\n<br>Unable to connect to " + baseURL;
return null;
}
}
}
catch (Exception e)
{
// System.Windows.Forms.MessageBox.Show("2");
if (wr != null)
{
wr.Abort();
}
error.errorName = e.ToString();
error.errorDescription = e.Message + "\n<br>Unable to connect to " + baseURL;
return null;
}
fail = 0;
while (rd.Read())
{
if (rd.NodeType == System.Xml.XmlNodeType.Element)
{
if (rd.Name == "responseDate")
{
presponseDate = rd.ReadString();
}
else if (rd.Name=="ListRecords")
{
do
{
if (rd.Name=="record")
{
tmp = ParseOAIContainer(ref rd, "record");
objRecord = new Record(tmp,ref objHandler);
objList.record.Add(objRecord);
//return objRecord;
}
else if (rd.Name=="resumptionToken")
{
tmp=rd.ReadOuterXml();
myToken = new ResumptionToken(tmp);
objList.token = myToken;
}
//else if (rd.Name.ToLower() == "OAI-PMH".ToLower())
//{
// break;
//}
else if (rd.EOF == true)
{
error.errorName = "Empty ListRecords Request";
error.errorDescription = "No data was returned in the ListRecords Element. This is likely an error.";
return null;
}
else rd.Read(); // Added the Read() and will never occur with the ReadInnerXml()
} while (rd.Name!="ListRecords"); // loop
}
else if (rd.Name=="error")
{
error.errorName = rd.GetAttribute("code");
error.errorDescription = rd.ReadString();
return null;
}
}
}
return objList;
}
public Record GetRecord(string sidentifier, string sPrefix, ref Object objHandler)
{
System.IO.Stream objStream;
Record objRecord;
string tmp = "";
System.Net.HttpWebRequest wr;
System.Xml.XmlTextReader rd;
if (sPrefix.Length==0)
{
sPrefix = "oai_dc";
}
prequestURL = baseURL + "?verb=GetRecord&metadataPrefix=" + sPrefix + "&identifier=" + sidentifier;
//======================================================
// If you wanted to support additional metadata formats,
// you would just need to have additional handlers.
//======================================================
try
{
wr = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(prequestURL);
wr.UserAgent = cUserAgent;
System.Net.WebResponse response = wr.GetResponse();
objStream = response.GetResponseStream();
System.IO.StreamReader reader = new System.IO.StreamReader(objStream);
prawXML = reader.ReadToEnd();
reader.Close();
rd = new System.Xml.XmlTextReader(prawXML, System.Xml.XmlNodeType.Document, null);
}
catch (Exception e)
{
error.errorName = e.ToString();
error.errorDescription = e.Message + "\n<br>Unable to connect to " + baseURL;
return null;
}
while (rd.Read())
{
if (rd.NodeType == System.Xml.XmlNodeType.Element)
{
if (rd.Name == "responseDate")
{
presponseDate = rd.ReadString();
}
else if (rd.Name=="GetRecord")
{
do
{
if (rd.Name=="record")
{
tmp = ParseOAIContainer(ref rd, "record");
objRecord = new Record(tmp, ref objHandler);
return objRecord;
}
else rd.Read(); // Added the Read() and will never occur with the ReadInnerXml()
} while (rd.Name!="GetRecord"); // loop
}
else if (rd.Name=="error")
{
error.errorName = rd.GetAttribute("code");
error.errorDescription = rd.ReadString();
return null;
}
}
}
return null;
}