Question

我正在学习如何将数据发送到外部数据库并且代码可以工作但是至少可以说它有点小问题。我正在使用this教程，而且很多代码已经折旧了，所以我一直在努力更新它。

当用户点击同步按钮时，应该将SQLite数据库中保存的数据发送到外部数据库。发生这种情况但随后应用程序崩溃。我不清楚日志中的解决方案，我不确定如何纠正问题。我已设法将崩溃隔离到这部分代码中，这部分代码是折旧的（成功时，失败时）。

我已经对AsyncHTTPResponseHandler进行了研究，并认为代码很好，正如我之前所说，它确实连接到数据库并插入到表中，但随后立即崩溃。我把我认为存在问题的代码和日志猫一起放了。

public void syncSQLiteMySQLDB() {
    //Create AsycHttpClient object
    AsyncHttpClient client = new AsyncHttpClient();
    RequestParams params = new RequestParams();
    ArrayList<HashMap<String, String>> userList = controller.getAllUsers();
    if (userList.size() != 0) {
        if (controller.dbSyncCount() != 0) {
            prgDialog.show();
            params.put("usersJSON", controller.composeJSONfromSQLite());
            client.post("http://jakebreen.co.uk/android/sqlitemysqlsync/inseruser.php", params, new AsyncHttpResponseHandler() {
                @Override
                public void onSuccess(int statusCode, Header[] headers, byte[] response) {
                    System.out.println(response);
                    prgDialog.hide();
                    try {
                        JSONArray arr = new JSONArray(response);
                        System.out.println(arr.length());
                        for (int i = 0; i < arr.length(); i++) {
                            JSONObject obj = (JSONObject) arr.get(i);
                            System.out.println(obj.get("id"));
                            System.out.println(obj.get("status"));
                            controller.updateSyncStatus(obj.get("id").toString(), obj.get("status").toString());
                        }
                        Toast.makeText(getApplicationContext(), "DB Sync completed!", Toast.LENGTH_LONG).show();
                    } catch (JSONException e) {
                        // TODO Auto-generated catch block
                        Toast.makeText(getApplicationContext(), "Error Occured [Server's JSON response might be invalid]!", Toast.LENGTH_LONG).show();
                        e.printStackTrace();
                    }
                }

                @Override
                public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {

                    // TODO Auto-generated method stub
                    prgDialog.hide();
                    if (statusCode == 404) {
                        Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
                    } else if (statusCode == 500) {
                        Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
                    } else {
                        Toast.makeText(getApplicationContext(), "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet]", Toast.LENGTH_LONG).show();
                    }
                }
            });
        } else {
            Toast.makeText(getApplicationContext(), "SQLite and Remote MySQL DBs are in Sync!", Toast.LENGTH_LONG).show();
        }
    } else {
        Toast.makeText(getApplicationContext(), "No data in SQLite DB, please do enter User name to perform Sync action", Toast.LENGTH_LONG).show();
    }
}

记录猫

              --------- beginning of crash
E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.year2.sqlitemysqlsync, PID: 2281
              java.lang.RuntimeException: java.lang.ClassCastException: java.lang.Byte cannot be cast to org.json.JSONArray
                  at com.loopj.android.http.AsyncHttpResponseHandler.onUserException(AsyncHttpResponseHandler.java:304)
                  at com.loopj.android.http.AsyncHttpResponseHandler.handleMessage(AsyncHttpResponseHandler.java:395)
                  at com.loopj.android.http.AsyncHttpResponseHandler$ResponderHandler.handleMessage(AsyncHttpResponseHandler.java:510)
                  at android.os.Handler.dispatchMessage(Handler.java:102)
                  at android.os.Looper.loop(Looper.java:135)
                  at android.app.ActivityThread.main(ActivityThread.java:5254)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at java.lang.reflect.Method.invoke(Method.java:372)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
               Caused by: java.lang.ClassCastException: java.lang.Byte cannot be cast to org.json.JSONArray
                  at com.year2.sqlitemysqlsync.MainActivity$1.onSuccess(MainActivity.java:102)
                  at com.loopj.android.http.AsyncHttpResponseHandler.handleMessage(AsyncHttpResponseHandler.java:351)
                  at com.loopj.android.http.AsyncHttpResponseHandler$ResponderHandler.handleMessage(AsyncHttpResponseHandler.java:510) 
                  at android.os.Handler.dispatchMessage(Handler.java:102) 
                  at android.os.Looper.loop(Looper.java:135) 
                  at android.app.ActivityThread.main(ActivityThread.java:5254) 
                  at java.lang.reflect.Method.invoke(Native Method) 
                  at java.lang.reflect.Method.invoke(Method.java:372) 
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 
Application terminated.

Answer 1

而不是

JSONArray arr = new JSONArray(response);

试

JSONArray arr = new JSONArray(new String(response));

数据插入数据库然后应用程序崩溃

1 个答案: