android 網絡請求+json解析 最優分析

最近在項目中使用到了網絡請求，網頁數據以 json的方式返回，所以也避免不了json解析。衆所周知，android爲防止UI 阻塞，所以耗時操作時候都需要用戶異步的方式處理。雖然進行了異步處理，但是速度上還是應該儘可能快。最後分析得出–HttpURLConnection+GSON解析最優。

一： 網絡請求 httpClient or HttpURLConnection

1. 在Android 2.3及以上版本，使用的是HttpURLConnection，而在Android2.2及以下版本，使用的是HttpClient。至於爲什麼新版本爲什麼不推薦使用，則是谷歌對其不怎麼更新，支持不太高。

2. HttpURLConnection是一種多用途、輕量極的HTTP客戶端，使用它來進行HTTP操作可以適用於大多數的應用程序。雖然HttpURLConnection的API提供的比較簡單，但是同時這也使得我們可以更加容易地去使用和擴展它。

3. 但是如果不是簡單網頁，比如需要登錄後與服務器保持連接的話，還是推薦使用httpClient，通過set-cookies方式。

   這些都是比較書面化的定義，在實際的項目中測試了一下速度。httpURLConnect會更快一些，畢竟是讀取字節流的方式讀取json信息。

    // httpClient Get
    public static String connServerResult(String strUrl) {
        // 請求服務器的URL地址
        // 返回數據轉換成String
        HttpGet httpRequest = new HttpGet(strUrl);

        String strResult = null;

        try {

            HttpClient httpClient = new DefaultHttpClient();

            HttpResponse httpResponse = httpClient.execute(httpRequest);
            int code = httpResponse.getStatusLine().getStatusCode();
            if (code == HttpStatus.SC_OK) {
                Log.v("lzw", "PoiSearch-connServerResult-1");
                strResult = EntityUtils.toString(httpResponse.getEntity());

            }

        } catch (Exception e) {

        }

        return strResult;
    }

//httpURlConnect  採用回調方式處理異步事件
public static void getHttpResponse(final String allConfigUrl) {

        new Thread(new Runnable() {
            public void run() {
                BufferedReader in = null;
                StringBuffer result = null;
                HttpURLConnection connection = null;
                try {

                    URL url = new URL(allConfigUrl);
                    connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                    connection.setRequestProperty("Charset", "utf-8");
                    if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                        result = new StringBuffer();
                        // 讀取URL的響應
                        in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                        String line;
                        while ((line = in.readLine()) != null) {
                            result.append(line);
                        }
                        Message msg_navigation = mHandler.obtainMessage();
                        msg_navigation.what = 0;
                        msg_navigation.obj = result.toString();
                        mHandler.sendMessage(msg_navigation);
                    }

                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    try {
                        if (connection != null) {
                            connection.disconnect();
                            connection = null;
                        }
                        if (in != null) {
                            in.close();
                            in = null;
                        }
                    } catch (Exception e2) {
                        e2.printStackTrace();
                    }
                }

            }

        }).start();

    }

    //執行回調函數，處理異步事件。
    public static void doHttpUtilsCallBaockListener(final HttpUtilsCallbackListener listener) {
        mHandler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                super.handleMessage(msg);
                switch (msg.what) {
                case 0:
                    String str = (String) msg.obj;
                    listener.success(str);
                    break;

                default:

                    break;
                }
            }
        };
    }

    public interface HttpUtilsCallbackListener {
        void success(String str);
    }

 經過上面兩種方式，對我請求的一個路徑導航的網頁，httpClient大概3385ms httpURLConncet 2025ms。同等情況下 httpURLConnect性能更優。

二. JSON解析。
測試一個北京到上海的路徑導航API網頁數據，大約json裏面座標數組幾萬個，此時良好的解析方式將會凸顯出性能的優劣。
我在處理json解析的時候用到三種方式；

1. 第一種 傳統android自帶的解析方式，使用JSONObject 解析對象， JSONArray 解析數組。

2. 第二種 阿里巴巴開源提供的fastjson.

3. 第三種 谷歌提供的GSON。

實際在幾萬個數據的解析下 谷歌GSON解析更勝一籌，領先fastjson 幾秒，最慢也是自帶的 JSONObject .
最後附上GSON解析相關類。fastjson 和傳統JSONObject 將不再贅述。

//PoiGsonBean 類
public class PoiGsonBean {
    private List<PoiInfos> poiInfos;


    private int totalHits;

    public void setPoiInfos(List<PoiInfos> poiInfos) {
        this.poiInfos = poiInfos;
    }

    public List<PoiInfos> getPoiInfos() {
        return this.poiInfos;
    }

    public void setTotalHits(int totalHits) {
        this.totalHits = totalHits;
    }

    public int getTotalHits() {
        return this.totalHits;
    }

    public static class PoiInfos {
        private String address;

        private Location location;

        private String name;

        private int score;

        private String telephone;

        private String uid;

        public void setAddress(String address) {
            this.address = address;
        }

        public String getAddress() {
            return this.address;
        }

        public void setLocation(Location location) {
            this.location = location;
        }

        public Location getLocation() {
            return this.location;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getName() {
            return this.name;
        }

        public void setScore(int score) {
            this.score = score;
        }

        public int getScore() {
            return this.score;
        }

        public void setTelephone(String telephone) {
            this.telephone = telephone;
        }

        public String getTelephone() {
            return this.telephone;
        }

        public void setUid(String uid) {
            this.uid = uid;
        }

        public String getUid() {
            return this.uid;
        }

    }
    public class PathInfos {

        public double pathLength;
        public List<Location> pathPoints;

        public double getPathLength(){

            return pathLength;
        }
        public void setPathLength(){

            this.pathLength=pathLength;

        }

        public List<Location> getPathPoints (){

            return pathPoints;
        }
        public void setPathPoints (List<Location> pathPoints){

            this.pathPoints=pathPoints;

        }
    }

    public static class Location {

        private double x;

        private double y;

        public void setX(double x) {
            this.x = x;
        }

        public double getX() {
            return this.x;
        }

        public void setY(double y) {
            this.y = y;
        }

        public double getY() {
            return this.y;
        }
    }
    public static class Junction {

        private double x;

        private double y;

        public void setX(double x) {
            this.x = x;
        }

        public double getX() {
            return this.x;
        }

        public void setY(double y) {
            this.y = y;
        }

        public double getY() {
            return this.y;
        }
    }
}

//json解析類
public class JsonPara {
    //解析POI 
    public void parsePOI(String strResult, ArrayList<PoiInfos> locationList) {
        Type type = new TypeToken<PoiGsonBean>() {
        }.getType();
        Gson gson = new Gson();
        PoiGsonBean poiGsonBean = gson.fromJson(strResult, type);
        locationList.clear();
        locationList.addAll(poiGsonBean.getPoiInfos());

    }
    //解析路徑導航
    public void parseNavigation(String strResult, ArrayList<Location> LocationList) {

        Type type = new TypeToken<PathInfos>() {
        }.getType();
        Gson gson = new Gson();
        PathInfos pathInfos = gson.fromJson(strResult, type);
        LocationList.addAll(pathInfos.getPathPoints());

    }

}