我想从服务器解析JSON数据:
我创建了这样的activity_main.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" android:background="#F1F1F1"
tools:context=".MainActivity" >
<ListView
android:id="@+id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:listitem="@layout/row" >
</ListView>
并创建了listview-row.xml,如下所示:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="4dp"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<ImageView
android:id="@+id/ivImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="8dp"
android:src="@drawable/ic_launcher" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="@+id/tvName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="ചെമ്മീന് തീയല്"
android:textColor="#166CED"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="@+id/tvCategory"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#D64530"
android:text="Non-Veg" />
</LinearLayout>
</LinearLayout>
<TextView
android:id="@+id/tvPreparation"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#009A57"
android:text="sdfdfds " />
之后我创建了这样的Actors类:
public class Actors {
private String name;
private String preparation;
private String category;
private String photo;
public Actors() {
// TODO Auto-generated constructor stub
}
public Actors(String name, String preparation, String category, String photo) {
super();
this.name = name;
this.preparation = preparation;
this.category = category;
this.photo = photo;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPreparation() {
return preparation;
}
public void setPreparation(String preparation) {
this.preparation = preparation;
}
public String getCategory() {
return category;
}
public void setCategory(String category) {
this.category = category;
}
public String getPhoto() {
return photo;
}
public void setPhoto(String photo) {
this.photo = photo;
}
}
然后我创建了这样的Actors Adapter:
public class ActorAdapter extends ArrayAdapter<Actors> {
ArrayList<Actors> actorList;
LayoutInflater vi;
int Resource;
ViewHolder holder;
public ActorAdapter(Context context, int resource, ArrayList<Actors> objects) {
super(context, resource, objects);
vi = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
Resource = resource;
actorList = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// convert view = design
View v = convertView;
if (v == null) {
holder = new ViewHolder();
v = vi.inflate(Resource, null);
holder.imageview = (ImageView) v.findViewById(R.id.ivImage);
holder.tvName = (TextView) v.findViewById(R.id.tvName);
holder.tvPreparation = (TextView) v.findViewById(R.id.tvPreparation);
holder.tvCategory = (TextView) v.findViewById(R.id.tvCategory);
v.setTag(holder);
} else {
holder = (ViewHolder) v.getTag();
}
holder.imageview.setImageResource(R.drawable.ic_launcher);
new DownloadImageTask(holder.imageview).execute(actorList.get(position).getPhoto());
holder.tvName.setText(actorList.get(position).getName());
holder.tvPreparation.setText(actorList.get(position).getPreparation());
holder.tvCategory.setText(actorList.get(position).getCategory());
return v;
}
static class ViewHolder {
public ImageView imageview;
public TextView tvName;
public TextView tvPreparation;
public TextView tvCategory;
}
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
}
我在MainActivity中调用了适配器,如下所示:
public class MainActivity extends Activity {
ArrayList<Actors> actorsList;
ActorAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
actorsList = new ArrayList<Actors>();
new JSONAsyncTask().execute("http://localhost:8000/api/recepie");
ListView listview = (ListView)findViewById(R.id.list);
adapter = new ActorAdapter(getApplicationContext(), R.layout.row, actorsList);
listview.setAdapter(adapter);
listview.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position,
long id) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(), actorsList.get(position).getName(), Toast.LENGTH_LONG).show();
}
});
}
class JSONAsyncTask extends AsyncTask<String, Void, Boolean> {
ProgressDialog dialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
dialog = new ProgressDialog(MainActivity.this);
dialog.setMessage("Loading, please wait");
dialog.setTitle("Connecting server");
dialog.show();
dialog.setCancelable(false);
}
@Override
protected Boolean doInBackground(String... urls) {
try {
//------------------>>
HttpGet httppost = new HttpGet(urls[0]);
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(httppost);
// StatusLine stat = response.getStatusLine();
int status = response.getStatusLine().getStatusCode();
if (status == 200) {
HttpEntity entity = response.getEntity();
String data = EntityUtils.toString(entity);
JSONObject jsono = new JSONObject(data);
JSONArray jarray = jsono.getJSONArray("recepies");
for (int i = 0; i < jarray.length(); i++) {
JSONObject object = jarray.getJSONObject(i);
Actors actor = new Actors();
actor.setName(object.getString("name"));
actor.setPreparation(object.getString("preparation"));
actor.setCategory(object.getString("category"));
actor.setPhoto(object.getString("photo"));
actorsList.add(actor);
}
return true;
}
//------------------>>
} catch (ParseException e1) {
e1.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return false;
}
protected void onPostExecute(Boolean result) {
dialog.cancel();
adapter.notifyDataSetChanged();
if(result == false)
Toast.makeText(getApplicationContext(), "Unable to fetch data from server", Toast.LENGTH_LONG).show();
}
}
但是“无法从服务器获取数据”,我在Android Monitor中发现了两个错误..第一个是从GradienCache获取MAX_TEXTURE_SIZE ,并且从Caches :: initConstraints()获取MAX_TEXTURE_SIZE 。我的JSON解析有什么问题吗? 我该怎么做才能纠正这些代码?