為了讓Android能夠快速地訪問網絡和解析通用的數據格式Google專門推出了Volley庫，用於Android系統的網絡傳輸。volley庫可以方便地獲取遠程服務器的圖片、字符串、json對象和json對象數組等。當然，java本身也有獲取json對象的方法，然而為了更好地適應移動互聯網，google專門為其做了特殊的優化，因而應該盡可能地使用Volley庫。
Volley官方文檔：https://developer.android.com/training/volley/index.html
Volley庫下載：git clone https://android.googlesource.com/platform/frameworks/volley/（由於用到google，因而需要做一些特殊的處理；您可參考前面的文章“git無法clone遠程代碼庫及git代理設置”）
環境：Android Studio
一、將Volley庫導入到Android工程中（此處采用的是源碼導入的方式，更多方式導入方式可參考“Android Studio 簡介及導入 jar 包和第三方開源庫方法”）：
1、將下載好的源碼拷貝到app同級目錄下，在setting.gradle下添加volley庫支持
include ':app', ':volley'
2、在app/build.gradle中的dependencies下添加
compile project(':volley')
最后結果如下：
dependencies { compile fileTree(include: ['*.jar'], dir: 'libs') compile 'com.android.support:appcompat-v7:23.0.1' compile project(':volley') }
至此，volley褲已經添加到了工程中。下面看看如何通過volley庫正確地讀取遠程服務器上的json對象和json數組。
由於要訪問網絡，因此需要對網絡權限進行設置。在AndroidManifest.xml中添加如下權限設置。
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
二、獲取服務器json對象
1、服務器中json對象數據格式
{"linkmd5id":"c07e1ddae86029dbd1f4fb79a6f532fc","view":"149","comment":"1","diggnum":"0","postdate":"2015-10-15 12:59","updated":"2015-10-15 07:25:58"}
2、獲取json對象
RequestQueue requestQueue = Volley.newRequestQueue(this); String jsonUrl = "http://152.123.55.102:8080/json.html"; JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, jsonUrl, null, new Response.Listener<JSONObject>() { @Override public void onResponse(JSONObject response) { System.out.println("json data===" + response); } }, new Response.ErrorListener(){ @Override public void onErrorResponse(VolleyError error) { System.out.println("發生了一個錯誤！"); error.printStackTrace(); } }); requestQueue.add(jsonObjectRequest);
3、運行結果：
10-19 16:34:26.376 24583-24583/com.example.news.andoridnewsapp I/System.out﹕ json data==={"diggnum":"0","postdate":"2015-10-15 12:59","view":"149","comment":"1","updated":"2015-10-15 07:25:58","linkmd5id":"c07e1ddae86029dbd1f4fb79a6f532fc"}
三、獲取json對象數組
1、原數組
[{"linkmd5id":"c07e1ddae86029dbd1f4fb79a6f532fc","title":"\u3010\u539f\u521b\u3011ZeroClipboard\u7684\u65f6\u4ee3\u6216\u8bb8\u5df2\u7ecf\u8fc7\u53bb\u4e86","desc":"\n","link":"http:\/\/www.cnblogs.com\/mawuhen\/p\/4882104.html","listurl":null,"view":"149","comment":"1","diggnum":"0","postdate":"2015-10-15 12:59","updated":"2015-10-15 07:25:58"},{"linkmd5id":"3bf8dd1f81a47a83895e8c55669c6631","title":"Web APi\u4e4b\u6355\u83b7\u8bf7\u6c42\u539f\u59cb\u5185\u5bb9\u7684\u5b9e\u73b0\u65b9\u6cd5\u4ee5\u53ca\u63a5\u53d7POST\u8bf7\u6c42\u591a\u4e2a\u53c2\u6570\u591a\u79cd\u89e3\u51b3\u65b9\u6848\uff08\u5341\u56db\uff09","desc":"\n","link":"http:\/\/www.cnblogs.com\/CreateMyself\/p\/4874273.html","listurl":null,"view":"165","comment":"5","diggnum":"6","postdate":"2015-10-15 12:38","updated":"2015-10-15 07:25:58"},{"linkmd5id":"39375a02b70c6b0a395f42bd97c60cdb","title":"SharePoint API\u6d4b\u8bd5\u7cfb\u5217\u2014\u2014Records.BypassLocks\u6d4b\u8bd5","desc":"\n","link":"http:\/\/www.cnblogs.com\/LanTianYou\/p\/4882050.html","listurl":null,"view":"50","comment":"0","diggnum":"0","postdate":"2015-10-15 12:31","updated":"2015-10-15 07:25:58"},{"linkmd5id":"be0e6182fb6fb216e58d21f08e54278e","title":"C#\u59d4\u6258\u4f7f\u7528\u8be6\u89e3\uff08Delegates\uff09","desc":"\n","link":"http:\/\/www.cnblogs.com\/liuhaorain\/p\/3911845.html","listurl":null,"view":"226","comment":"1","diggnum":"0","postdate":"2015-10-15 11:47","updated":"2015-10-15 07:25:58"},{"linkmd5id":"d85434e0d6e088a972f53447bf769256","title":"golang reflect","desc":"\n","link":"http:\/\/www.cnblogs.com\/coder2012\/p\/4881854.html","listurl":null,"view":"86","comment":"0","diggnum":"0","postdate":"2015-10-15 11:25","updated":"2015-10-15 07:25:58"},{"linkmd5id":"9e6d443d4c2f489179c22830437e8034","title":"Android Bitmap\u5b9e\u6218\u6280\u5de7","desc":"\n \u6ce8\uff1a\u672c\u6587\u5927\u91cf\u53c2\u8003\u8c37\u6b4c\u5b98\u65b9\u6587\u6863\u81eahttp:\/\/developer.android.com\/intl\/zh-cn\/training\/displaying-bitmaps\/index.html\u3002\u5982\u679c\u4f60\u81ea\u5b66\u80fd\u529b\u8fd8\u53ef\u4ee5\u6216\u8005\u82f1\u6587\u7406\u89e3\u80fd\u529b\u4e0d\u9519\u53ef\u4ee5\u76f4\u63a5\u53bb\u770b\u539f\u7248\u7684\u3002\u5982\u679c\u4f60\u65f6\u95f4\u5b9d\u8d35\uff0c\u60f3\u76f4\u63a5\u770b\u7ed3\u8bba\u548c\u6211\u4e2a\u4eba\u7406\u89e3\u7684\u5fc3\u5f97\uff0c\u4e5f\u53ef... \n ","link":"http:\/\/www.cnblogs.com\/punkisnotdead\/p\/4881771.html","listurl":null,"view":"116","comment":"1","diggnum":"0","postdate":"2015-10-15 11:08","updated":"2015-10-15 07:25:58"},{"linkmd5id":"71bf86ad9eb586aecdca37b9df43acb0","title":"\u3010\u7ec4\u4ef6\u5316\u5f00\u53d1\u3011\u524d\u7aef\u8fdb\u9636\u7bc7\u4e4b\u5982\u4f55\u7f16\u5199\u53ef\u7ef4\u62a4\u53ef\u5347\u7ea7\u7684\u4ee3\u7801","desc":"\n","link":"http:\/\/www.cnblogs.com\/yexiaochai\/p\/4876099.html","listurl":null,"view":"510","comment":"7","diggnum":"19","postdate":"2015-10-15 11:05","updated":"2015-10-15 07:25:58"},{"linkmd5id":"794568d4689bf1c3fc5b6de7945cd978","title":"WPF\u5165\u95e8\u6559\u7a0b\u7cfb\u5217\u4e8c\u5341\u4e00\u2014\u2014DataGrid\u793a\u4f8b(\u4e00)","desc":"\n \u524d\u9762\u6211\u4eec\u5b66\u4e60\u4e86ListView\u63a7\u4ef6\u7684\u4f7f\u7528\u793a\u4f8b\uff0c\u4eca\u5929\u6211\u4eec\u6765\u5b66\u4e60DataGrid\u7684\u6709\u5173\u77e5\u8bc6\u3002\u63d0\u5230DataGrid \u4e0d\u7ba1\u662fAsp.Net\u4e2d\u7684\u7f51\u9875\u5f00\u53d1\u8fd8\u662fWinForm\u5e94\u7528\u7a0b\u5e8f\u5f00\u53d1\u90fd\u4f1a\u9891\u7e41\u4f7f\u7528\u3002\u901a\u8fc7\u5b83\u6211\u4eec\u53ef\u4ee5\u7075\u6d3b\u7684\u5728\u884c\u4e0e\u5217\u95f4\u663e\u793a\u5404\u79cd\u6570\u636e\u3002\u672c\u7bc7\u5c06\u5b66\u4e60WPF\u4e2d\u7684DataGrid \u76f8\u5173\u529f\u80fd\u3002 \n ","link":"http:\/\/www.cnblogs.com\/chillsrc\/p\/4881724.html","listurl":null,"view":"168","comment":"1","diggnum":"2","postdate":"2015-10-15 10:59","updated":"2015-10-15 07:25:58"},{"linkmd5id":"668996b90dc6901e3cd9b8a57c3053ec","title":"Kafka\u9879\u76ee\u5b9e\u6218\uff0d\u7528\u6237\u65e5\u5fd7\u4e0a\u62a5\u5b9e\u65f6\u7edf\u8ba1\u4e4b\u7f16\u7801\u5b9e\u8df5","desc":"\n","link":"http:\/\/www.cnblogs.com\/smartloli\/p\/4881690.html","listurl":null,"view":"173","comment":"1","diggnum":"2","postdate":"2015-10-15 10:50","updated":"2015-10-15 07:25:58"},{"linkmd5id":"c02f4087c3de0d74a1c4e63c2922f963","title":"\u8be6\u7ec6\u89e3\u8bf4\u4eff\u5236QQ\u5217\u8868 \u5c55\u5f00\u548c\u6536\u8d77\u5217\u8868","desc":"\n \u8fd1\u6765\u516c\u53f8\u7684\u9879\u76ee\u8981\u5199\u4e2a\u7c7b\u4f3c\u4e8eQQ\u5217\u8868\u5c55\u5f00\u548c\u6536\u8d77\u7684\u5217\u8868\uff0c\u60f3\u5230\u4ee5\u524d\u674e\u660e\u6770\u89c6\u9891\u91cc\u8bf4\u7684\uff0c\u5c31\u5199\u4e2a\u4e86\u5c55\u5f00\u548c\u6536\u8d77\u7684Demo\uff0c\u5e0c\u671b\u7ed9\u65b0\u624b\u4e00\u70b9\u601d\u8def\uff0c\u4e0e\u5927\u5bb6\u5171\u540c\u8fdb\u6b65\u6211\u5199\u7684\u8fd9\u4e2a\u5c55\u5f00\u548c\u6536\u8d77\u7684\u601d\u8def\u662f\uff0c\u7528\u4e00\u4e2a\u5b57\u5178\u7684Key\u53bb\u8bb0\u5f55\u70b9\u51fb\u4e86\u7b2c\u51e0\u7ec4\uff0c\u7528\u72b6\u60010-1\u53bb\u8bb0\u5f55\u4ed6\u4eec\u662f\u5c55\u5f00\u7684\u8fd8\u662f\u6536\u8d77\u7684\u5e9f\u8bdd\u4e0d\u591a\u8bf4\uff0c\u4e0a\u4ee3\u7801\uff0c\u6ce8\u91ca\u5df2\u5199\uff0c\u4e00\u5b9a\u8981\u8ba4\u771f\u770b\u54e6\uff0c\u8ba4\u771f... \n ","link":"http:\/\/www.cnblogs.com\/bcblogs\/p\/4881612.html","listurl":null,"view":"449","comment":"2","diggnum":"2","postdate":"2015-10-15 10:27","updated":"2015-10-15 07:25:58"}]
2、獲取json對象數組
String jsonUrArrUrl = "http://152.123.55.102:8080/index.php"; JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(Request.Method.GET, jsonUrArrUrl, null, new Response.Listener<JSONArray>(){ @Override public void onResponse(JSONArray response) { System.out.println("json data===" + response); } }, new Response.ErrorListener(){ @Override public void onErrorResponse(VolleyError error) { System.out.println("發生了一個錯誤！"); error.printStackTrace(); } }); requestQueue.add(jsonArrayRequest);
3、運行結果
10-19 16:34:31.046 24583-24583/com.example.news.andoridnewsapp I/System.out﹕ json data===[{"diggnum":"0","postdate":"2015-10-15 12:59","title":"【原創】ZeroClipboard的時代或許已經過去了","desc":"\n","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/mawuhen\/p\/4882104.html","view":"149","listurl":null,"comment":"1","linkmd5id":"c07e1ddae86029dbd1f4fb79a6f532fc"},{"diggnum":"6","postdate":"2015-10-15 12:38","title":"Web APi之捕獲請求原始內容的實現方法以及接受POST請求多個參數多種解決方案（十四）","desc":"\n","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/CreateMyself\/p\/4874273.html","view":"165","listurl":null,"comment":"5","linkmd5id":"3bf8dd1f81a47a83895e8c55669c6631"},{"diggnum":"0","postdate":"2015-10-15 12:31","title":"SharePoint API測試系列——Records.BypassLocks測試","desc":"\n","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/LanTianYou\/p\/4882050.html","view":"50","listurl":null,"comment":"0","linkmd5id":"39375a02b70c6b0a395f42bd97c60cdb"},{"diggnum":"0","postdate":"2015-10-15 11:47","title":"C#委托使用詳解（Delegates）","desc":"\n","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/liuhaorain\/p\/3911845.html","view":"226","listurl":null,"comment":"1","linkmd5id":"be0e6182fb6fb216e58d21f08e54278e"},{"diggnum":"0","postdate":"2015-10-15 11:25","title":"golang reflect","desc":"\n","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/coder2012\/p\/4881854.html","view":"86","listurl":null,"comment":"0","linkmd5id":"d85434e0d6e088a972f53447bf769256"},{"diggnum":"0","postdate":"2015-10-15 11:08","title":"Android Bitmap實戰技巧","desc":"\n 注：本文大量參考谷歌官方文檔自http:\/\/developer.android.com\/intl\/zh-cn\/training\/displaying-bitmaps\/index.html。如果你自學能力還可以或者英文理解能力不錯可以直接去看原版的。如果你時間寶貴，想直接看結論和我個人理解的心得，也可... \n ","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/punkisnotdead\/p\/4881771.html","view":"116","listurl":null,"comment":"1","linkmd5id":"9e6d443d4c2f489179c22830437e8034"},{"diggnum":"19","postdate":"2015-10-15 11:05","title":"【組件化開發】前端進階篇之如何編寫可維護可升級的代碼","desc":"\n","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/yexiaochai\/p\/4876099.html","view":"510","listurl":null,"comment":"7","linkmd5id":"71bf86ad9eb586aecdca37b9df43acb0"},{"diggnum":"2","postdate":"2015-10-15 10:59","title":"WPF入門教程系列二十一——DataGrid示例(一)","desc":"\n 前面我們學習了ListView控件的使用示例，今天我們來學習DataGrid的有關知識。提到DataGrid 不管是Asp.Net中的網頁開發還是WinForm應用程序開發都會頻繁使用。通過它我們可以靈活的在行與列間顯示各種數據。本篇將學習WPF中的DataGrid 相關功能。 \n ","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/chillsrc\/p\/4881724.html","view":"168","listurl":null,"comment":"1","linkmd5id":"794568d4689bf1c3fc5b6de7945cd978"},{"diggnum":"2","postdate":"2015-10-15 10:50","title":"Kafka項目實戰－用戶日志上報實時統計之編碼實踐","desc":"\n","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/smartloli\/p\/4881690.html","view":"173","listurl":null,"comment":"1","linkmd5id":"668996b90dc6901e3cd9b8a57c3053ec"},{"diggnum":"2","postdate":"2015-10-15 10:27","title":"詳細解說仿制QQ列表 展開和收起列表","desc":"\n 近來公司的項目要寫個類似於QQ列表展開和收起的列表，想到以前李明傑視頻里說的，就寫個了展開和收起的Demo，希望給新手一點思路，與大家共同進步我寫的這個展開和收起的思路是，用一個字典的Key去記錄點擊了第幾組，用狀態0-1去記錄他們是展開的還是收起的廢話不多說，上代碼，注釋已寫，一定要認真看哦，認真... \n ","updated":"2015-10-15 07:25:58","link":"http:\/\/www.cnblogs.com\/bcblogs\/p\/488
這樣便可方便地獲取到json格式的數據。在此暢想一下，如果結合sqllite，是否可以異步獲取差異數據進而以最小的流量獲取更新的內容呢？
更多官方例子可在此查看：https://developer.android.com/training/volley/index.html