我正在开发一个Android应用程序。我使用xampp服务器来使用mysql。当我运行应用程序时，它应该与mysql和retreive值同步并将其存储在sqlite中。我在链接http://programmerguru.com/android-tutorial/how-to-sync-remote-mysql-db-to-sqlite-on-android/中尝试此示例。以同样的方式我开发了代码，但是在示例中，我使用的链接中有一个名为syncsts的列，用于跟踪同步。但问题是当一个用户使用应用程序并且状态获得时，同步会更新如果其他用户使用该应用程序，则不会发生同步。
我怀疑是
我的代码是
MainActivity.java
public class MainActivity extends Activity implements OnClickListener
{
TextView update,updating;
Button btn1,btn2;
HashMap<String, String> queryValues;
DBController controller = new DBController(this);
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
AsyncHttpClient client = new AsyncHttpClient();
RequestParams params = new RequestParams();
client.post("http://192.168.1.104/website/getdbrowcount.php",params ,new AsyncHttpResponseHandler() {
@Override
public void onSuccess(String response)
{
System.out.println(response);
try
{
Log.d("home", "success");
// Create JSON object out of the response sent by getdbrowcount.php
JSONObject obj = new JSONObject(response);
Log.d("home", obj.toString());
System.out.println(obj.get("count"));
// If the count value is not zero,
if(obj.getInt("count") != 0)
{
Log.d("home", "count not equal to zero");
AlertDialog.Builder myalert=new AlertDialog.Builder(MainActivity.this);
myalert.setTitle("New product data available");
Log.d("home", "count");
myalert.setMessage("New product data is available.Would you like to download and update?");
myalert.setPositiveButton("ok", new DialogInterface.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int arg1)
{
// TODO Auto-generated method stub
// Transfer data from remote MySQL DB to SQLite on Android and perform Sync
syncDB();
update.setText("Started syncing to server");
btn2.setVisibility(View.VISIBLE);
}
});
myalert.setNegativeButton("cancel", new DialogInterface.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int arg1)
{
// TODO Auto-generated method stub
update.setText("The update has been cancelled. Please update via Settings to work"
+ " with latest Sonetonix product data");
btn1.setEnabled(true);
btn1.setTextColor(Color.parseColor("#FFFFFF"));
btn2.setVisibility(View.GONE);
}
});
myalert.show();
}
else
{
Log.d("home", "count is equal to zero");
update.setText("New Products are not available. Please keep updating for the new products..");
btn1.setEnabled(true);
btn1.setTextColor(Color.parseColor("#FFFFFF"));
btn2.setVisibility(View.GONE);
}
}
catch (JSONException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void onFailure(int statusCode, Throwable error,String content)
{
}
});
}
public void syncDB()
{
Log.d("home", "db sync");
// Create AsycHttpClient object
AsyncHttpClient client = new AsyncHttpClient();
// Http Request Params Object
RequestParams params = new RequestParams();
client.post("http://192.168.1.104/website/getusers.php", params, new AsyncHttpResponseHandler()
{
@Override
public void onSuccess(String response)
{
// Update SQLite DB with response sent by getusers.php
updatesqlite(response);
}
// When error occured
@Override
public void onFailure(int statusCode, Throwable error, String content)
{
}
});
}
public void updatesqlite(String response)
{
Log.d("home",response);
ArrayList<HashMap<String, String>> usersynclist;
usersynclist = new ArrayList<HashMap<String, String>>();
// Create GSON object
Gson gson = new GsonBuilder().create();
try
{
// Extract JSON array from the response
JSONArray arr = new JSONArray(response);
System.out.println(arr.length());
// If no of array elements is not zero
if(arr.length() != 0)
{
for (int i = 0; i < arr.length(); i++)
{
// Get JSON object
JSONObject obj = (JSONObject) arr.get(i);
System.out.println(obj.get("productId"));
System.out.println(obj.get("category"));
System.out.println(obj.get("subcategory"));
System.out.println(obj.get("mountingstyle"));
System.out.println(obj.get("products"));
System.out.println(obj.get("description"));
// DB QueryValues Object to insert into SQLite
queryValues = new HashMap<String, String>();
queryValues.put("productId", obj.get("productId").toString());
queryValues.put("category", obj.get("category").toString());
queryValues.put("subcategory", obj.get("subcategory").toString());
queryValues.put("mountingstyle", obj.get("mountingstyle").toString());
queryValues.put("products", obj.get("products").toString());
queryValues.put("description", obj.get("description").toString());
// Insert User into SQLite DB
controller.insertUser(queryValues);
Log.d("home","inserted properly");
HashMap<String, String> map = new HashMap<String, String>();
// Add status for each User in Hashmap
Log.d("home",map.toString());
map.put("products", obj.get("products").toString());
map.put("status", "1");
usersynclist.add(map);
System.out.println("---------------------------------------------" + usersynclist);
Log.d("home",map.toString());
Handler handler = new Handler();
handler.postDelayed(new Runnable()
{
@Override
public void run()
{
//Do something after 100ms
}
}, 4000);
}
// Inform Remote MySQL DB about the completion of Sync activity by passing Sync status of Users
updatesyncsts(gson.toJson(usersynclist));
// Reload the Main Activity
reloadActivity();
}
}
catch (JSONException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// Method to inform remote MySQL DB about completion of Sync activity
public void updatesyncsts(String json)
{
System.out.println(json);
AsyncHttpClient client = new AsyncHttpClient();
RequestParams params = new RequestParams();
params.put("syncsts", json);
System.out.println(params);
// Make Http call to updatesyncsts.php with JSON parameter which has Sync statuses of Users
client.post("http://192.168.1.104/website/updatesyncsts.php", params, new AsyncHttpResponseHandler()
{
@Override
public void onSuccess(String response)
{
Log.d("home",response);
btn2.setVisibility(View.GONE);
btn1.setEnabled(true);
btn1.setTextColor(Color.parseColor("#FFFFFF"));
}
@Override
public void onFailure(int statusCode, Throwable error, String content)
{
}
});
}
// Reload MainActivity
public void reloadActivity()
{
Intent objIntent = new Intent(getApplicationContext(), MainActivity.class);
startActivity(objIntent);
update.setText("Updated successfully");
}
}
DBController.java
public class DBController extends SQLiteOpenHelper
{
private static final String DATABASE_NAME = "SonetonixProducts.db";
private static final int DATABASE_VERSION = 1;
public DBController(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
Log.d("home",DATABASE_NAME);
}
@Override
public void onCreate(SQLiteDatabase database)
{
String query;
query="CREATE TABLE guide (slno INTEGER PRIMARY KEY AUTOINCREMENT, productId INTEGER, category TEXT, subcategory TEXT, mountingstyle TEXT, products TEXT, description TEXT )";
// TODO Auto-generated method stub
database.execSQL(query);
Log.d("home","table created");
}
@Override
public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion)
{
// TODO Auto-generated method stub
String query;
query= "DROP TABLE IF EXISTS guide";
database.execSQL(query);
onCreate(database);
}
public void insertUser(HashMap<String, String> queryValues)
{
SQLiteDatabase database = this.getWritableDatabase();
Log.d("home",database.toString());
ContentValues values = new ContentValues();
values.put("productId", queryValues.get("productId"));
values.put("category", queryValues.get("category"));
values.put("subcategory", queryValues.get("subcategory"));
values.put("mountingstyle", queryValues.get("mountingstyle"));
values.put("products", queryValues.get("products"));
values.put("description", queryValues.get("description"));
database.insert("guide", null, values);
database.close();
Log.d("home","inserted");
}
public ArrayList<String> getAllUsers()
{
ArrayList<String> usersList;
usersList = new ArrayList<String>();
String selectQuery = "SELECT category,subcategory FROM guide";
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
Log.d("home", cursor.toString());
if (cursor.moveToFirst()) {
do {
usersList.add(cursor.getString(0));
}while (cursor.moveToNext());
}
database.close();
return usersList;
}
public ArrayList<HashMap<String, String>> getUsers() {
ArrayList<HashMap<String, String>> usersList;
usersList = new ArrayList<HashMap<String, String>>();
String selectQuery = "SELECT category,subcategory FROM guide";
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do {
HashMap<String, String> map = new HashMap<String, String>();
map.put(cursor.getString(0), cursor.getString(1));
usersList.add(map);
} while (cursor.moveToNext());
}
database.close();
return usersList;
}
}
我如何实现这一目标。请帮助出院
答案 0 :(得分：0)
您可以在各种免费托管网站（例如https://www.2freehosting.com）上托管您的网络服务和数据库，托管后您可以在Android中提供网络服务的URL。然后，您可以在任何网络上访问数据库和Web服务。
修改1：
对于问题的定期或高效同步，请定期查看：https://developer.android.com/training/sync-adapters/index.html