GAE/JのurlfetchでXMLHttpRequestを実装してみた

GAE/Jで Socket 使う場合には urlfetch しか使えない。
こいつはかなり低機能なので HttpURLConnection がラッパとして有るのだがこいつも結構使いづらい。

JavaScript使いなら当然 XMLHttpRequest が使いたいよね、
と言うわけで urlfetch で XMLHttpRequest を実装してみました。
非同期は出来ないけど。

package kotemaru.wsjs.gae;





import java.io.*;


import java.net.*;


import java.text.*;


import java.util.*;


import javax.xml.parsers.*;


import org.w3c.dom.*;


import org.xml.sax.*;


import org.mozilla.javascript.*;


//import kotemaru.util.LOG ;


//import kotemaru.wsjs.Config ;


import javax.servlet.http.HttpSession;


import com.google.appengine.api.urlfetch.*;


//import kotemaru.wsjs.ssjs.SsjsEnv;





/**


TODO: 非同期、キャッシュ、クッキー


*/


public class XMLHttpRequest {


	private static final String GET = "GET";


	private static final String POST = "POST";


	private static final String CONTENT_TYPE = "content-type";


	private static final String SET_COOKIE = "set-cookie";





	//private final SsjsEnv __ENV__;


	private final URLFetchService fetcher;


	private HTTPRequest request = null;


	private String overrideMimeType = null;





	private HTTPResponse response = null;


	private int status = 0;


	private Map<String, String> responseHeaderMap = null;


	private String responseText = null;


	private Document responseXML = null;


	public String charset = null; //TODO:





	//public XMLHttpRequest(SsjsEnv env) {


	public XMLHttpRequest() {


		//__ENV__ = env;


		fetcher = URLFetchServiceFactory.getURLFetchService();


		


/* TODO: urlfetch のプロキシの設定方法が分からん。


		String proxyHost = Config.getProxyHost();


		int proxyPort = Config.getProxyPort();


		if (proxyHost != null && proxyHost.length()>0 ) {


			client.getHostConfiguration().setProxy(proxyHost, proxyPort);


		}


*/


	}





	public void open(String type, String url) throws Exception {


		open(type, url, false);


	}


	public void open(String type, String url, boolean isAsync) throws Exception {


		if (isAsync) {


			throw new RuntimeException("Unsupported async XMLHttpRequest.");


		}


		if (GET.equalsIgnoreCase(type)) {


			request = new HTTPRequest(new URL(url), HTTPMethod.GET);


		} else {


			request = new HTTPRequest(new URL(url), HTTPMethod.POST);


			this.setRequestHeader(CONTENT_TYPE, "text/plain; charset=utf-8");


		}


		this.setRequestHeader("Connection","close");


	}


	public void close() throws Exception {


		// nop.?


	}





	public void overrideMimeType(String ctype) {


		overrideMimeType = ctype.trim().toLowerCase();


	}


	public void setRequestHeader(String name, String value) {


		request.setHeader(new HTTPHeader(name, value));


	}


	public String getResponseHeader(String name) {


		return responseHeaderMap.get(name);


	}





	private String getContentType() {


		if (overrideMimeType != null) return overrideMimeType;


		String val = getResponseHeader(CONTENT_TYPE);


		if (val == null) return null;


		return val.trim().toLowerCase();


	}





	public void send(String body) throws Exception {


		//__ENV__.LOG.info("XREQ.send|"+__ENV__.getUser()+"|"+__ENV__.getPage()+"|"+request.getMethod()+" "+request.getURL());


		//if (__ENV__.getWsjsContext().getAppConfig() != null) {


		//	__ENV__.getWsjsContext().getAppConfig().addXreqCount();


		//}


		try {


			_send(body);


		} finally {


			// TODO: close


		}


	}


	private void _send(String body) throws Exception {





		if (request.getMethod() == HTTPMethod.POST) {


			request.setPayload(body.getBytes("utf-8"));


		}


		response = fetcher.fetch(request);


		status = response.getResponseCode();


		responseHeaderMap = parseResponseHeader(response);





		//if (__ENV__.LOG.isDebugEnabled()) debugLog();





		String ctype = getContentType();


		if (ctype.startsWith("text/xml")


			|| ctype.startsWith("application/xhtml+xml")


			|| ctype.startsWith("application/rss+xml")) {


			DocumentBuilder builder =


				DocumentBuilderFactory.newInstance().newDocumentBuilder();


			byte[] resbody = response.getContent();


			ByteArrayInputStream in = new ByteArrayInputStream(resbody);


			responseXML = builder.parse(in);


		} else {


			byte[] resbody = response.getContent();


			if (charset == null) {


				responseText = new String(resbody, "utf-8");


			} else {


				responseText = new String(resbody, charset);


			}


		}


	}


	private Map<String, String> parseResponseHeader(HTTPResponse response) {


		List<HTTPHeader>	headers = response.getHeaders();


		Map<String, String> map = new HashMap<String, String>(headers.size());


		for (HTTPHeader h : headers) {


			String name = h.getName().toLowerCase();


			String val = map.get(name);


			if (val == null) {


				map.put(name, h.getValue());


			} else {


				map.put(name, val+", "+h.getValue());


			}


			if (CONTENT_TYPE.equals(name)) {


				this.charset = parseCharset(h.getValue());


			}


			if (SET_COOKIE.equals(name)) {


				// TODO:Cookieパーザ


			}


		}


		return map;


	}


	private String parseCharset(String ctype) {


		String[] parts = ctype.split(";");


		for (int i=0; i<parts.length; i++) {


			String part = parts[i].trim();


			if (part.startsWith("charset")) {


				String[] pair = part.split("=");


				if (pair.length > 1) return pair[1].trim();


			}


		}


		return null;


	}








	public int getStatus() {


		return status;


	}


	public String getResponseText() {


		return 	responseText;


	}


	public Document getResponseXML() throws Exception {


		return responseXML;


	}





/*


	private void debugLog() throws Exception {


		String msg = "XREQ request detail.\n";


		msg += ">> "+request.getMethod()+" "+request.getURL()+"\n";


		List<HTTPHeader>	headers = response.getHeaders();


		for (HTTPHeader h : headers) {


			msg += ">> "+h.getName()+": "+h.getValue()+"\n";


		}





		msg += "\n<< "+response.getResponseCode()+"\n";


		headers = response.getHeaders();


		for (HTTPHeader h : headers) {


			msg += "<< "+h.getName()+": "+h.getValue()+"\n";


		}





		__ENV__.LOG.debug(msg);


	}


*/


}

Rhino からこんな感じで使えてる。

function doGet(req, res) {


	var xreq = new XMLHttpRequest();


	xreq.open("GET","http://www.google.co.jp/");


	xreq.send(null);





	res.setContentType("text/plain");


	res.writer.write(xreq.responseText);


}