org.xins.server.XMLCallingConvention Maven / Gradle / Ivy
/*
* $Id: XMLCallingConvention.java,v 1.57 2012/02/28 18:10:54 agoubard Exp $
*
* See the COPYRIGHT file for redistribution and use restrictions.
*/
package org.xins.server;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;
import org.w3c.dom.Element;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.xins.common.text.TextUtils;
import org.xins.common.xml.ElementList;
/**
* XML calling convention.
*
* @version $Revision: 1.57 $ $Date: 2012/02/28 18:10:54 $
* @author Anthony Goubard
*/
public class XMLCallingConvention extends CallingConvention {
/**
* The response encoding format.
*/
protected static final String RESPONSE_ENCODING = "UTF-8";
/**
* The content type of the HTTP response.
*/
protected static final String RESPONSE_CONTENT_TYPE = "text/xml; charset=" + RESPONSE_ENCODING;
@Override
protected String[] getSupportedMethods() {
return new String[] { "POST" };
}
/**
* Checks if the specified request can be handled by this calling
* convention.
*
* This method will not throw any exception.
*
* @param httpRequest
* the HTTP request to investigate, cannot be null.
*
* @return
* true if this calling convention is possibly
* able to handle this request, or false if it
* definitely not able to handle this request.
*
* @throws Exception
* if analysis of the request causes an exception;
* false will be assumed.
*/
protected boolean matches(HttpServletRequest httpRequest)
throws Exception {
// Parse the XML in the request (if any)
Element element = parseXMLRequest(httpRequest);
return element.getTagName().equals("request") &&
!TextUtils.isEmpty(element.getAttribute("function"));
}
/**
* Converts an HTTP request to a XINS request (implementation method). This
* method should only be called from class CallingConvention. Only
* then it is guaranteed that the httpRequest argument is not
* null.
*
* @param httpRequest
* the HTTP request, will not be null.
*
* @return
* the XINS request object, never null.
*
* @throws InvalidRequestException
* if the request is considerd to be invalid.
*
* @throws FunctionNotSpecifiedException
* if the request does not indicate the name of the function to execute.
*/
protected FunctionRequest convertRequestImpl(HttpServletRequest httpRequest)
throws InvalidRequestException,
FunctionNotSpecifiedException {
Element requestElem = parseXMLRequest(httpRequest);
String functionName = requestElem.getAttribute("function");
// Determine function parameters
Map functionParams = new HashMap();
ElementList parameters = new ElementList(requestElem, "param");
for (int i = 0; i < parameters.size(); i++) {
Element nextParam = (Element) parameters.get(i);
String name = nextParam.getAttribute("name");
String value = nextParam.getTextContent();
functionParams.put(name, value);
}
// Check if function is specified
if (TextUtils.isEmpty(functionName)) {
throw new FunctionNotSpecifiedException();
}
// Remove all invalid parameters
cleanUpParameters(functionParams);
// Get data section
Element dataElement = null;
ElementList dataElementList = new ElementList(requestElem, "data");
if (dataElementList.size() == 1) {
dataElement = (Element) dataElementList.get(0);
} else if (dataElementList.size() > 1) {
throw new InvalidRequestException("Found multiple data sections.");
}
return new FunctionRequest(functionName, functionParams, dataElement);
}
/**
* Converts a XINS result to an HTTP response (implementation method).
*
* @param xinsResult
* the XINS result object that should be converted to an HTTP response,
* will not be null.
*
* @param httpResponse
* the HTTP response object to configure, will not be null.
*
* @param backpack
* the request backpack, will not be null.
*
* @throws IOException
* if calling any of the methods in httpResponse causes an
* I/O error.
*/
protected void convertResultImpl(FunctionResult xinsResult,
HttpServletResponse httpResponse,
Map backpack)
throws IOException {
// Send the XML output to the stream and flush
httpResponse.setContentType(RESPONSE_CONTENT_TYPE);
PrintWriter out = httpResponse.getWriter();
httpResponse.setStatus(HttpServletResponse.SC_OK);
CallResultOutputter.output(out, xinsResult);
out.close();
}
}