我的代码显示错误，我不知道究竟是什么导致它，这一行：HttpURLConnection con = client.open（new URL（imageUrl））;
package www.com.easyrecepee;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.view.LayoutInflater;
import android.util.LruCache;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
/**
* Created by Joshua on 9/28/2016.
*/
public class PlacesListAdapter extends ArrayAdapter<Places> {
private Context context;
private List<Places> placesList;
private LruCache<String, Bitmap> imageCache;
// create a field of the RequestQueue to be used by volley
// so it persist through out the life time of the class
//private RequestQueue queue;
public OkHttpClient client = new OkHttpClient();
public PlacesListAdapter(Context context, int resources, List<Places> objects) {
super(context, resources, objects);
this.context = context;
this.placesList = objects;
final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
final int cacheSize = maxMemory / 8;
imageCache = new LruCache<>(cacheSize);
// instantiate the queue field and passing current context
// so its associated with proper activity
//queue = Volley.newRequestQueue(context);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater =
(LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
View view = inflater.inflate(R.layout.item_vicinity, parent, false);
// Display places name in the TextView widget
final Places places = placesList.get(position);
TextView placeTitle = (TextView) view.findViewById(R.id.place_title);
TextView vicinity = (TextView) view.findViewById(R.id.vicinity);
//TextView openNow = (TextView)view.findViewById(R.id.openNow);
placeTitle.setText(places.getName());
vicinity.setText(places.getVicinity());
// if(places.isOpenNow()){
// openNow.setText("Open");
// } else {
// openNow.setText("Closed");
// }
//Display place photo in ImageView widget
Bitmap bitmap = imageCache.get(places.getId());
// for volley
final ImageView image = (ImageView) view.findViewById(R.id.place_image);
if (bitmap != null) {
//For the volley, this commented line of code is refactored so it can
// be called outside this block
//ImageView image = (ImageView) view.findViewById(R.id.place_image);
image.setImageBitmap(places.getBitmap());
} else {
// Retrieves image url
//String imageUrl = places.getIconUrl();
// declare instance of image request
/*ImageRequest request = new ImageRequest(imageUrl,
new Response.Listener<Bitmap>(){
@Override
public void onResponse(Bitmap arg0) {
image.setImageBitmap(arg0);
imageCache.put(places.getId(), arg0);
}
},
80, 80,
Bitmap.Config.ARGB_8888,
new Response.ErrorListener(){
@Override
public void onErrorResponse(VolleyError arg0) {
Log.d("PlacesAdapter", arg0.getMessage());
}
}
);
//adding request to queue
queue.add(request);*/
/*
The line of code below is used by the ImageLoader AsyncTask
Uncomment if using AsyncTask
*/
PlaceAndView container = new PlaceAndView();
container.places = places;
container.view = view;
ImageLoader loader = new ImageLoader();
loader.execute(container);
}
return view;
}
// Used with AsyncTask, since am using Volley, no need
class PlaceAndView {
public Places places;
public View view;
public Bitmap bitmap;
}
// Using the Volley Method does what the AsyncTask do
// Uncomment to use
private class ImageLoader extends AsyncTask<PlaceAndView, Void, PlaceAndView> {
@Override
protected PlaceAndView doInBackground(PlaceAndView... params) {
PlaceAndView container = params[0];
Places places = container.places;
try {
String imageUrl = places.getIconUrl();
// Using OkHttpClient to fetch images
HttpURLConnection con = client.open(new URL(imageUrl));
//HttpURLConnection connection = (HttpURLConnection) url.openConnection();
InputStream in = con.getInputStream();
}
//InputStream in = (InputStream) new URL(imageUrl).getContent();
Bitmap bitmap = BitmapFactory.decodeStream(in);
places.setBitmap(bitmap);
in.close();
container.bitmap = bitmap;
return container;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(PlaceAndView result) {
ImageView image = (ImageView) result.view.findViewById(R.id.place_image);
image.setImageBitmap(result.bitmap);
// saves image for future use
//result.places.setBitmap(result.bitmap);
imageCache.put(result.places.getId(), result.bitmap);
}
}
}
如何让open（）方法停止显示错误，这是在代码中创建错误的唯一方法，所以我觉得应该有一些其他方法或更新的方法来处理open方法。
答案 0 :(得分：0)
我想你在这里复制相同的代码Fatal Exception: Exception in do in background method (AsyncTask)
所以我想你可以根据需要修改这段代码，看看你的代码是否运行。
@Override
protected FlowerAndView doInBackground(FlowerAndView... params) {
FlowerAndView container = params[0];
Flower flower = container.flower;
try {
String imageUrl = MainActivity.PHOTOS_BASE_URL + flower.getPhoto();
InputStream in = (InputStream) new URL(imageUrl).getContent();
Bitmap bitmap = BitmapFactory.decodeStream(in);
flower.setBitmap(bitmap);
in.close();
container.bitmap = bitmap;
return container;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
<强> [EDITED]
但是使用OkHttpClient，您的代码应该是这样的。
@Override
protected PlaceAndView doInBackground(PlaceAndView... params) {
PlaceAndView container = params[0];
Places places = container.places;
try {
String imageUrl = places.getIconUrl();
// Using OkHttpClient to fetch images
// HttpURLConnection con = client.open(new URL(imageUrl));
//HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//InputStream in = con.getInputStream();
Request req = new Request.Build()
.url(imageUrl)
.build();
Response response = client.newCall(req).execute();
InputStream in = response.body().byteStream();
//InputStream in = (InputStream) new URL(imageUrl).getContent();
Bitmap bitmap = BitmapFactory.decodeStream(in);
places.setBitmap(bitmap);
in.close();
container.bitmap = bitmap;
return container;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
PS：请记住，有很多库可以下载图片glide，picasso等，以节省时间和代码。
如何使用Glide的示例，请注意您需要的代码少。
public class PlacesListAdapter extends ArrayAdapter<Places> {
private LayoutInflater mInflater;
public PlacesListAdapter(Context context, int resources, List<Places> objects) {
super(context, resources, objects);
mInflater = LayoutInflater.from(context);
}
class Holder {
TextView placeTitle;
TextView vicinity;
ImageView placeImage;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = convertView;
Holder holder;
if (view == null) {
view = mInflater.inflate(R.layout.item_vicinity, parent, false);
holder = new Holder();
holder.placeTitle = (TextView) view.findViewById(R.id.place_title);
holder.vicinity (TextView) view.findViewById(R.id.vicinity);
holder.placeImage = (ImageView) view.findViewById(R.id.place_image);
view.setTag(holder);
} else {
holder = view.getTag();
}
// Display places name in the TextView widget
final Places places = getItem(position);
holder.placeTitle.setText(places.getName());
holder.vicinity.setText(places.getVicinity());
Glide
.with(parent.getContext())
.load(places.getIconUrl())
.into(holder.placeImage);
return view;
}
}