需要实现Android App端与PHP Web端的简单数据交互的实现，当前场景是Web端使用的是MySql数据库，Apache服务器和PHP 语言编写的。数据交互的简单理解就是Android能向服务端进行数据获取，同时也能进行数据提交。
实现流程
流程说明
Andorid Server端对MySql数据库进行简单的查询操作，并将查询数据结果转换为Json格式提供给Andorid利用OKhttp读取再解析Json展示到APP上；同时Andorid端利用OKhttp提交给Andorid Server端，由Server端对MySql数据库对提交数据的添加。
Apache Server端通过解析PHP源代码，对MySql数据库的增删查改显示在WebSite。
具体实现
Andorid Server
获取数据
get_all_found_items.php
<?php \nheader(\'Content-Type:text/html;charset=utf-8\');/*设置php编码为utf-8*/\n/* \n * Following code will list all the items \n */ \n \n// array for JSON response \n$response = array(); \n \n// include db connect class \nrequire_once __DIR__ . \'/db_connect.php\'; \n \n// connecting to db \n$db = new DB_CONNECT(); \n \n// get all items from items table \n$result = mysql_query(\"SELECT *FROM items WHERE type=\'1\'\") or die(mysql_error()); \n// check for empty result \nif (mysql_num_rows($result) 0) { \n // looping through all results \n // items node \n $response[\"items\"] = array(); \n \n while ($row = mysql_fetch_array($result)) { \n // temp user array \n $items = array(); \n $items[\"what\"] = $row[\"what\"]; \n $items[\"when\"] = $row[\"when\"]; \n $items[\"where\"] = $row[\"where\"]; \n $items[\"detail\"] = $row[\"detail\"];\n $items[\"posttime\"] = $row[\"posttime\"]; \n $resultcontcat = mysql_query(\"SELECT *FROM guests\") or die(mysql_error()); \n while ($row1 = mysql_fetch_array($resultcontcat)) { \n if ($row1[\"id\"] == $row[\"gid\"]){\n $items[\"contact\"] = $row1[\"contact\"];\n }\n }\n // push single items into final response array \n array_push($response[\"items\"], $items); \n } \n // success \n $response[\"success\"] = 1; \n \n // echoing JSON response \n echo json_encode($response,JSON_UNESCAPED_UNICODE); \n} else { \n // no items found \n $response[\"success\"] = 0; \n $response[\"message\"] = \"No items found\"; \n \n // echo JSON \n echo json_encode($response,JSON_UNESCAPED_UNICODE); \n} \n?
如以上PHP代码可知通过require_once()函数包含db_connect.php文件，执行数据库配置文件。定义数组$response接收查询的数据结果，通过判断不同的情况赋值$response[“success”]，并返回到Web页面显示
PHP文件执行结果JSON
{\n \"items\": [\n {\n \"what\": \"手表\",\n \"when\": \"2017-10-21 00:00:00\",\n \"where\": \"北区宿舍楼#504\",\n \"detail\": \"白色的手表，XX品牌\",\n \"posttime\": \"2017-10-21 13:03:09\",\n \"contact\": \"138123456\"\n },\n {\n \"what\": \"手机\",\n \"when\": \"2017-10-04 00:00:00\",\n \"where\": \"北区商店#111\",\n \"detail\": \"iphone6s,土豪金\",\n \"posttime\": \"2017-10-21 13:03:46\",\n \"contact\": \"137123456\"\n },\n {\n \"what\": \"电脑\",\n \"when\": \"2017-10-21 14:39:54\",\n \"where\": \"图书馆#203\",\n \"detail\": \"联想品牌笔记本\",\n \"posttime\": \"2017-10-21 17:08:14\",\n \"contact\": \"5670001\"\n },\n {\n \"what\": \"细说PHP\",\n \"when\": \"2017-09-21 13:03:46\",\n \"where\": \"南馆#403\",\n \"detail\": \"黑色封面，第二版《细说PHP》\",\n \"posttime\": \"2017-10-21 17:36:53\",\n \"contact\": \"63513641\"\n }\n ],\n \"success\": 1\n}
提交数据
create_found_items.php
<?php \nheader(\'Content-Type:text/html;charset=utf-8\');/*设置php编码为utf-8*/ \n/* \n * Following code will create a new product row \n * All product details are read from HTTP GET Request \n */ \n \n// array for JSON response \n$response = array(); \n \n// check for required fields \nif (isset($_GET[\'what\']) && isset($_GET[\'when\']) && isset($_GET[\'where\']) && isset($_GET[\'detail\'])&& isset($_GET[\'contact\'])) { \n \n $what = $_GET[\'what\']; \n $when = $_GET[\'when\']; \n $where = $_GET[\'where\']; \n $detail = $_GET[\'detail\']; \n $contact = $_GET[\'contact\']; \n \n // include db connect class \n require_once __DIR__ . \'/db_connect.php\'; \n \n // connecting to db \n $db = new DB_CONNECT(); \n \n // mysql inserting a new row \n $result2 = mysql_query(\"INSERT INTO guests(contact) VALUES(\'$contact\')\"); \n $gidresult = mysql_query(\"SELECT id FROM guests WHERE contact=\'$contact\'\"); \n while ($row = mysql_fetch_array($gidresult)) { \n $gid=$row[\'id\'];\n }\n $result1 = mysql_query(\"INSERT INTO items(what, when, where, type ,gid, detail) VALUES(\'$what\', \'$when\', \'$where\', \'1\', \'$gid\', \'$detail\')\"); \n \n // check if row inserted or not \n if ($result1 && $result2) { \n // successfully inserted into database \n $response[\"success\"] = 1; \n $response[\"message\"] = \"Items successfully created.\"; \n \n // echoing JSON response \n echo json_encode($response,JSON_UNESCAPED_UNICODE); \n } else { \n // failed to insert row \n $response[\"success\"] = 0; \n $response[\"message\"] = \"Oops! An error occurred.\"; \n \n // echoing JSON response \n echo json_encode($response,JSON_UNESCAPED_UNICODE); \n } \n} else { \n // required field is missing \n $response[\"success\"] = 0; \n $response[\"message\"] = \"Required field(s) is missing\"; \n \n // echoing JSON response \n echo json_encode($response,JSON_UNESCAPED_UNICODE); \n} \n? 判断GET请求的参数是否都存在，把获取的GET请求参数作为数据INSERT TO MySQL数据库。判断INSERT执行过程赋值$response[“success”]对应相应的$response[“message”]，显示在Web页面。
Andorid
获取数据核心代码 queryLosts()函数
private void queryLosts() {\n losts.clear();\n new Thread(new Runnable() {\n \n @Override\n public void run() {\n // TODO Auto-generated method stub\n \n OkHttpClient okHttpClient = new OkHttpClient();\n String url = \"http://webSite/androidapi/get_all_lost_items.php\";\n Request request = new Request.Builder()\n .url(url)\n .build();\n Call call = okHttpClient.newCall(request);\n try {\n Response response = call.execute();\n String res = response.body().string();\n if (res != null && !res.trim().equals(\"\")){\n JSONObject jsonObject = new JSONObject(res);\n if (jsonObject.getInt(\"success\") == 1){\n JSONArray jsonArray = jsonObject.getJSONArray(\"items\");\n for (int i = jsonArray.length() - 1;i = 0;i--){\n JSONObject item = jsonArray.getJSONObject(i);\n String what = null;\n try {\n what = item.getString(\"what\");\n }catch (Exception e){\n }\n String when = null;\n try{\n when = item.getString(\"when\");\n }catch (Exception e){\n }\n String where = null;\n try{\n where = item.getString(\"where\");\n }catch (Exception e){\n }\n String detail = null;\n try {\n detail = item.getString(\"detail\");\n }catch (Exception e){\n }\n String contact = null;\n try {\n contact = item.getString(\"contact\");\n }catch (Exception e){\n }\n Lost lost = new Lost();\n lost.setTitle(what);\n String des = \"地点：\" + (where == null?\"\":where) +\" \"+\"时间：\" + (when == null?\"\":when)+\"r\" + \" \"+\"描述：\" + (detail == null?\"\":detail);\n lost.setDescribe(des);\n lost.setPhone(contact == null?\"\":contact);\n losts.add(lost);\n }\n }\n }\n } catch (Exception e) {\n e.printStackTrace();\n showErrorView(0);\n }\n if (losts == null || losts.size() == 0) {\n handler.sendEmptyMessage(1);\n return;\n }\n if (losts.size() 0){\n handler.sendEmptyMessage(2);\n }\n }\n }).start();利用Android网络框架OKhttp,OKhttp一个处理网络请求的开源项目,是安卓端最火热的轻量级框架.请求接口url地址，获取Json数据利用JSONObject对Json数据进行解析。
提交数据 核心代码 addLost()函数
public Handler handler = new Handler(){\n public void handleMessage(android.os.Message msg) {\n switch(msg.what){\n case 1:\n Toast.makeText(this,\"提交成功\",Toast.LENGTH_LONG).show();\n break;\n case 2:\n Toast.makeText(this,\"提交失败\",Toast.LENGTH_LONG).show();\n break;\n }\n }\n};\nprivate void addLost(){\n OkHttpClient okHttpClient = new OkHttpClient();\n String url =\"http://website/androidapi/create_lost_items.php?what=\"+title+\"&when=\"+time+\"&where=\"+place+\"&detail=\"+describe+\"&contact=\"+photo+\"\";\n Request request = new Request.Builder()\n .url(url)\n .build();\n \n try{\n Response response = okHttpClient.newCall(request).execute();\n res = response.body().string();\n handler.sendEmptyMessage(1);\n }catch (Exception e)\n {\n e.printStackTrace();\n handler.sendEmptyMessage(2);\n }\n}
同样利用Okhttp,GET方式提交参数，try-catch获取异常，通过返回值给出一定的提交结果提示。