1

我尝试使用 json 和AsyncTask. 但是我在这些线上得到了错误：

JSONObject json = jsonParser.makeHttpRequest(url_product_detials, "GET", params);

这是我的代码：

public class EditWatchListProducts extends Activity {

EditText txtName;
EditText txtPrice;
Button btnSave;
Button btnDelete;

String pid;

private ProgressDialog pDialog;

JSONParser jsonParser = new JSONParser();

        private static final String url_product_detials = "http://192.168.2.22/android_connect/get_product_details.php";

     private static final String url_update_product = "http://192.168.2.22/android_connect/update_product.php";

        private static final String url_delete_product = "http://192.168.2.22/android_connect/delete_product.php";

 private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCT = "product";
private static final String TAG_ID = "product_id";
private static final String TAG_NAME = "product_name";
private static final String TAG_PRICE = "target_price";
private static final String TAG_DESCRIPTION = "retailer";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.edit_watchlist_product);

    btnSave = (Button) findViewById(R.id.btnSave);
    btnDelete = (Button) findViewById(R.id.btnDelete);

    Intent i = getIntent();

   pid = i.getStringExtra(TAG_ID);

    new GetProductDetails().execute();

    btnSave.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            new SaveProductDetails().execute();
        }
    });

    btnDelete.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
             new DeleteProduct().execute();
        }
    });

}

 class GetProductDetails extends AsyncTask<String, String, String> {

  @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(EditWatchListProducts.this);
        pDialog.setMessage("Loading product details. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }
    protected String doInBackground(String... params) {

           runOnUiThread(new Runnable() {
            public void run() {
                // Check for success tag
                int success;
                try {
                    // Building Parameters
                    List<NameValuePair> params = new ArrayList<NameValuePair>();
                    params.add(new BasicNameValuePair("product_id", pid));

                    // getting product details by making HTTP request
                    // Note that product details url will use GET request
                    JSONObject json = jsonParser.makeHttpRequest(
                            url_product_detials, "GET", params);



                   success = json.getInt(TAG_SUCCESS);
                    if (success == 1) {
                        JSONArray productObj = json
                                .getJSONArray(TAG_PRODUCT); // JSON Array

                        JSONObject product = productObj.getJSONObject(0);
                        txtName = (EditText) findViewById(R.id.inputName);
                        txtPrice = (EditText) findViewById(R.id.inputPrice);
                        txtDesc = (EditText) findViewById(R.id.inputDesc);

                        txtName.setText(product.getString(TAG_NAME));
                        txtPrice.setText(product.getString(TAG_PRICE));
                        txtDesc.setText(product.getString(TAG_DESCRIPTION));

                    }else{
                        // product with pid not found
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        });

        return null;
    }

    protected void onPostExecute(String file_url) {
        pDialog.dismiss();
    }
}
class SaveProductDetails extends AsyncTask<String, String, String> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(EditWatchListProducts.this);
        pDialog.setMessage("Saving product ...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    protected String doInBackground(String... args) {

        String name = txtName.getText().toString();
        String price = txtPrice.getText().toString();
        String description = txtDesc.getText().toString();

        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair(TAG_ID, pid));
        params.add(new BasicNameValuePair(TAG_NAME, name));
        params.add(new BasicNameValuePair(TAG_PRICE, price));
        params.add(new BasicNameValuePair(TAG_DESCRIPTION, description));

        JSONObject json = jsonParser.makeHttpRequest(url_update_product,
                "POST", params);

        try {
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                Intent in = new Intent(getApplicationContext(),
                        WatchListProducts.class);
                 startActivity(in);
            } else {
                // failed to update product
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }
    protected void onPostExecute(String file_url) {
        pDialog.dismiss();
    }
}

class DeleteProduct extends AsyncTask<String, String, String> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(EditWatchListProducts.this);
        pDialog.setMessage("Deleting Product...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    protected String doInBackground(String... args) {

        int success;
        try {
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("product_id", pid));
            JSONObject json = jsonParser.makeHttpRequest(
                    url_delete_product, "POST", params);

            Log.d("Delete Product", json.toString());

            success = json.getInt(TAG_SUCCESS);
            if (success == 1) {
             Intent in = new Intent(getApplicationContext(),
                        WatchListProducts.class);
                 startActivity(in);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    protected void onPostExecute(String file_url) {
        pDialog.dismiss();

    }

  }
 }

编辑：

相同的代码在单独的项目上运行良好。当我用我的项目实施时，我会遇到以下异常......

我的代码有什么问题？？？

编辑：更新日志

     07-19 16:43:31.018: E/AndroidRuntime(3009): FATAL EXCEPTION: main
      07-19 16:43:31.018: E/AndroidRuntime(3009): android.os.NetworkOnMainThreadException
       07-19 16:43:31.018: E/AndroidRuntime(3009):  at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1084)
    07-19 16:43:31.018: E/AndroidRuntime(3009):     at java.net.InetAddress.lookupHostByName(InetAddress.java:391)
      07-19 16:43:31.018: E/AndroidRuntime(3009):   at java.net.InetAddress.getAllByNameImpl(InetAddress.java:242)
   07-19 16:43:31.018: E/AndroidRuntime(3009):  at java.net.InetAddress.getAllByName(InetAddress.java:220)
   07-19 16:43:31.018: E/AndroidRuntime(3009):  at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
   07-19 16:43:31.018: E/AndroidRuntime(3009):  at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
     07-19 16:43:31.018: E/AndroidRuntime(3009):    at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
     07-19 16:43:31.018: E/AndroidRuntime(3009):    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
     07-19 16:43:31.018: E/AndroidRuntime(3009):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
    07-19 16:43:31.018: E/AndroidRuntime(3009):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
   07-19 16:43:31.018: E/AndroidRuntime(3009):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
    07-19 16:43:31.018: E/AndroidRuntime(3009):     at com.example.androidbestinuk.JSONParser.makeHttpRequest(JSONParser.java:60)
   07-19 16:43:31.018: E/AndroidRuntime(3009):  at com.example.androidbestinuk.EditWatchListProducts$GetProductDetails$1.run(EditWatchListProducts.java:131)
       07-19 16:43:31.018: E/AndroidRuntime(3009):  at android.os.Handler.handleCallback(Handler.java:605)
   07-19 16:43:31.018: E/AndroidRuntime(3009):  at android.os.Handler.dispatchMessage(Handler.java:92)
     07-19 16:43:31.018: E/AndroidRuntime(3009):    at android.os.Looper.loop(Looper.java:137)
      07-19 16:43:31.018: E/AndroidRuntime(3009):   at android.app.ActivityThread.main(ActivityThread.java:4340)
    07-19 16:43:31.018: E/AndroidRuntime(3009):     at java.lang.reflect.Method.invokeNative(Native Method)
   07-19 16:43:31.018: E/AndroidRuntime(3009):  at java.lang.reflect.Method.invoke(Method.java:511)
   07-19 16:43:31.018: E/AndroidRuntime(3009):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
    07-19 16:43:31.018: E/AndroidRuntime(3009):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
  07-19 16:43:31.018: E/AndroidRuntime(3009):   at dalvik.system.NativeStart.main(Native Method)
4

2 回答 2

2

在这里，我们面临 networkOnMainThreadException 错误。所以我们使用以下 2 行意味着成功获取输出。

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);

希望对大家有所帮助。

于 2013-07-23T05:18:36.730 回答
2

你有 runOnUiThread哪个在ui线程上运行，你有这个

  JSONObject json = jsonParser.makeHttpRequest(
                        url_product_detials, "GET", params);

来自您在代码上方的评论getting product details by making HTTP request。所以你在 ui 线程上发出 http 请求。你会得到NetworkOnMainThreadException.

public final void runOnUiThread (Runnable action)

在 API 级别 1 中添加

在 UI 线程上运行指定的操作。如果当前线程是 UI 线程，则立即执行该操作。如果当前线程不是 UI 线程，则将动作发布到 UI 线程的事件队列中。

参数

action在 UI 线程上运行的操作

所以删除runOnUiThreadand update ui in onPreExecuteand onPostExecute. 在doInbackground.

于 2013-07-19T10:09:05.340 回答