ServiceDBHelper

此類別為自訂類別, 請由專案新增class, 並將如下代碼鍵入.

此類別用來跟資料庫伺服器進行連線, 在Class中, Class.forName(“net.sourceforge.jtds.jdbc.Driver”); 此行就是載入驅動程式的意思

jtds適用於Android 4.4以上(含), 若低於此版本, 在連線時會出現錯誤, 所以需在連線字串加上 charset=utf8;

public class ServerDBHelper {
    private Connection connection;
    private String server;
    private String database;
    private String userAccount;
    private String userPassword;
    Handler handler;
    public ServerDBHelper(Handler handler, String server, String database, String userAccount, String userPassword){
        this.handler=handler;
        this.server=server;
        this.database=database;
        this.userAccount=userAccount;
        this.userPassword=userPassword;
    }
    private Connection connectionHelper() throws SQLException, ClassNotFoundException{
        StrictMode.ThreadPolicy policy = (new StrictMode.ThreadPolicy.Builder()).permitAll().build();
        StrictMode.setThreadPolicy(policy);
        String connectionURL = null;
        Class.forName("net.sourceforge.jtds.jdbc.Driver");
        if (Build.VERSION.SDK_INT >= 19) {
            connectionURL = String.format("jdbc:jtds:sqlserver://%s;databaseName=%s;user=%s;password=%s;", this.server, this.database, this.userAccount, this.userPassword);
        } else {
            connectionURL = String.format("jdbc:jtds:sqlserver://%s;databaseName=%s;charset=utf8;user=%s;password=%s;", this.server, this.database, this.userAccount, this.userPassword);
        }
        return DriverManager.getConnection(connectionURL);
    }
    public Connection makeConnection(){
        try{
            if(connection!=null && !connection.isClosed()){
                connection.close();
            }
            connection=this.connectionHelper();
            return connection;
        }
        catch(SQLException e){
            Log.d("Thomas", e.getMessage());
        }
        catch(ClassNotFoundException e){
            Log.d("Thomas", e.getMessage());
        }
        return null;
    }
}

網路權限

因為連線到遠端資料庫伺服器, 需使用到網路, 所以記得在AndroidManifest.xml加上權限
<uses-permission android:name=“android.permission.INTERNET” />

用法

ServiceDBHelper為常用的類別, 所以上面的設計, 只需傳入handler, ip, 資料庫, 帳號, 密碼, 就可取得連線物件 .

因此會建議大家把此類別放入您自已的SDK內, 日後只要import即可使用. 像本人也好久沒在摸個類別了, 都快忘了當初怎麼寫出來的.

在主程式中, 只要產生ServiceDBHelper, 再調用makeConnection即可, 如下

serverDBHelper=new ServerDBHelper(handler, "ip", "資料庫", "帳號", "密碼");
Connection conn=serverDBHelper.makeConnection();