Volley 학습 노트 | 원본 코드에서 Request, Response, Listener 범주에 대한 이해 (XMLRequest 사용자 정의 코드 첨부)

소결 Volley에서 Response가 수신에서 업무로 전환되는 과정

/**
 * A canned request for retrieving the response body at a given URL as a String.
 */
public class StringRequest extends Request {
    private final Listener mListener;
 
    /**
     * Creates a new request with the given method.
     *
     * @param method the request {@link Method} to use
     * @param url URL to fetch the string at
     * @param listener Listener to receive the String response
     * @param errorListener Error listener, or null to ignore errors
     */
    public StringRequest(int method, String url, Listener listener,
            ErrorListener errorListener) {
        super(method, url, errorListener);
        mListener = listener;
    }
 
    /**
     * Creates a new GET request.
     *
     * @param url URL to fetch the string at
     * @param listener Listener to receive the String response
     * @param errorListener Error listener, or null to ignore errors
     */
    public StringRequest(String url, Listener listener, ErrorListener errorListener) {
        this(Method.GET, url, listener, errorListener);
    }
 
    @Override
    protected void deliverResponse(String response) {
        mListener.onResponse(response);
    }
 
    @Override
    protected Response parseNetworkResponse(NetworkResponse response) {
        String parsed;
        try {
            parsed = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
        } catch (UnsupportedEncodingException e) {
            parsed = new String(response.data);
        }
        return Response.success(parsed, HttpHeaderParser.parseCacheHeaders(response));
    }
}

@Override
    protected Response parseNetworkResponse(NetworkResponse response) {
        String parsed;
        try {
            parsed = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
        } catch (UnsupportedEncodingException e) {
            parsed = new String(response.data);
        }
        return Response.success(parsed, HttpHeaderParser.parseCacheHeaders(response));
    }

    @Override
    protected void deliverResponse(String response) {
        mListener.onResponse(response);
    }

        XMLRequest xmlRequest = new XMLRequest(
                "http://flash.weather.com.cn/wmaps/xml/china.xml",
                new Response.Listener() {
                    @Override
                    public void onResponse(XmlPullParser response) {
                        try {
                            int eventType = response.getEventType();
                            while (eventType != XmlPullParser.END_DOCUMENT) {
                                switch (eventType) {
                                    case XmlPullParser.START_TAG:
                                        String nodeName = response.getName();
                                        if ("city".equals(nodeName)) {
                                            String pName = response.getAttributeValue(0);
                                            Log.d("TAG", "pName is " + pName);

                                            reponseContent += pName;
                                            reponseContent += "
";
                                        }
                                        break;
                                }
                                eventType = response.next();
                            }
                            oriString = new String(reponseContent.getBytes("ISO-8859-1"), "utf-8");
                            responseText.setText(oriString);
                        } catch (XmlPullParserException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e("TAG", error.getMessage(), error);
            }
        });
        mQueue.add(xmlRequest);

public class XMLRequest extends Request {
 
    private final Listener mListener;
 
    public XMLRequest(int method, String url, Listener listener,
            ErrorListener errorListener) {
        super(method, url, errorListener);
        mListener = listener;
    }
 
    public XMLRequest(String url, Listener listener, ErrorListener errorListener) {
        this(Method.GET, url, listener, errorListener);
    }
 
    @Override
    protected Response parseNetworkResponse(NetworkResponse response) {
        try {
            String xmlString = new String(response.data,
                    HttpHeaderParser.parseCharset(response.headers));
            XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
            XmlPullParser xmlPullParser = factory.newPullParser();
            xmlPullParser.setInput(new StringReader(xmlString));
            return Response.success(xmlPullParser, HttpHeaderParser.parseCacheHeaders(response));
        } catch (UnsupportedEncodingException e) {
            return Response.error(new ParseError(e));
        } catch (XmlPullParserException e) {
            return Response.error(new ParseError(e));
        }
    }
 
    @Override
    protected void deliverResponse(XmlPullParser response) {
        mListener.onResponse(response);
    }
 
}