我在使用代碼失敗。 錯誤：android通用圖像加載器json
05-28 00:40:18.646: E/AndroidRuntime(854): FATAL EXCEPTION: main 05-28 00:40:18.646: E/AndroidRuntime(854): java.lang.NullPointerException 05-28 00:40:18.646: E/AndroidRuntime(854): at >com.nostra13.example.universalimageloader.ImageGridActivity$ImageAdapter.getView(ImageGrid>>activity.java:130) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.widget.AbsListView.obtainView(AbsListView.java:1430) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.widget.GridView.onMeasure(GridView.java:935) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.view.View.measure(View.java:8313) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.view.View.measure(View.java:8313) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.widget.LinearLayout.measureVertical(LinearLayout.java:531) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.widget.LinearLayout.onMeasure(LinearLayout.java:309) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.view.View.measure(View.java:8313) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.view.View.measure(View.java:8313) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.view.ViewRoot.performTraversals(ViewRoot.java:839) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.view.ViewRoot.handleMessage(ViewRoot.java:1859) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.os.Handler.dispatchMessage(Handler.java:99) 05-28 00:40:18.646: E/AndroidRuntime(854): at android.os.Looper.loop(Looper.java:123) 05-28 00:40:18.646: E/AndroidRuntime(854): at >android.app.ActivityThread.main(ActivityThread.java:3683) 05-28 00:40:18.646: E/AndroidRuntime(854): at >java.lang.reflect.Method.invokeNative(Native Method) 05-28 00:40:18.646: E/AndroidRuntime(854): at >java.lang.reflect.Method.invoke(Method.java:507) 05-28 00:40:18.646: E/AndroidRuntime(854): at >com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 05-28 00:40:18.646: E/AndroidRuntime(854): at >com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 05-28 00:40:18.646: E/AndroidRuntime(854): at dalvik.system.NativeStart.main(Native >Method)
我的代碼：
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;
public class ImageGridActivity extends Activity {
JSONArray str_json = null;
public static final int DIALOG_DOWNLOAD_JSON_PROGRESS = 0;
private ProgressDialog mProgressDialog;
ArrayList<HashMap<String, Object>> MyArrList;
String result = "";
@SuppressLint("NewApi")
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ac_image_grid);
// Permission StrictMode
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
}
// Download JSON File
new DownloadJSONFileAsync().execute();
}
@Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DIALOG_DOWNLOAD_JSON_PROGRESS:
mProgressDialog = new ProgressDialog(this);
mProgressDialog.setMessage("Downloading.....");
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mProgressDialog.setCancelable(true);
mProgressDialog.show();
return mProgressDialog;
default:
return null;
}
}
public void ShowAllContent() {
final GridView gridView1 = (GridView) findViewById(R.id.gridview);
gridView1
.setAdapter(new ImageAdapter(ImageGridActivity.this, MyArrList));
gridView1.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
Toast.makeText(getApplicationContext(), "this is",
Toast.LENGTH_SHORT).show();
}
});
}
public class ImageAdapter extends BaseAdapter {
private Context context;
private ArrayList<HashMap<String, Object>> MyArr = new ArrayList<HashMap<String, Object>>();
public ImageAdapter(Context c,
ArrayList<HashMap<String, Object>> myArrList) {
context = c;
MyArr = myArrList;
}
public int getCount() {
return MyArr.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
View myView = convertView;
viewHolder = new ViewHolder();
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
myView = inflater.inflate(R.layout.item_grid_image, null);
viewHolder.imageView = (ImageView) myView
.findViewById(R.id.image);
viewHolder.imageView.getLayoutParams().height = 120;
viewHolder.imageView.getLayoutParams().width = 120;
viewHolder.imageView.setPadding(5, 5, 5, 5);
viewHolder.imageView
.setScaleType(ImageView.ScaleType.CENTER_CROP);
try {
viewHolder.imageView.setImageBitmap((Bitmap) MyArr.get(
position).get("ImageThumBitmap"));
} catch (Exception e) {
viewHolder.imageView
.setImageResource(android.R.drawable.ic_menu_report_image);
}
}
return myView;
}
}
private static class ViewHolder {
public ImageView imageView;
}
// Download JSON in Background
public class DownloadJSONFileAsync extends AsyncTask<String, Void, Void> {
protected void onPreExecute() {
super.onPreExecute();
showDialog(DIALOG_DOWNLOAD_JSON_PROGRESS);
}
@Override
protected Void doInBackground(String... params) {
String url = "http://10.0.2.2/andro_stie/berita.php";
JSONParser jParser = new JSONParser();
JSONObject json = jParser.AmbilJson(url);
try {
str_json = json.getJSONArray("berita");
MyArrList = new ArrayList<HashMap<String, Object>>();
HashMap<String, Object> map;
for (int i = 0; i < str_json.length(); i++) {
JSONObject ar = str_json.getJSONObject(i);
map = new HashMap<String, Object>();
map.put("photo", (String) ar.getString("gambar"));
map.put("ImageThumBitmap",
(Bitmap) loadBitmap(ar.getString("gambar")));
// Full (for View Popup)
MyArrList.add(map);
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@SuppressWarnings("deprecation")
protected void onPostExecute(Void unused) {
ShowAllContent(); // When Finish Show Content
dismissDialog(DIALOG_DOWNLOAD_JSON_PROGRESS);
removeDialog(DIALOG_DOWNLOAD_JSON_PROGRESS);
}
}
/*** Get JSON Code from URL ***/
public String getJSONUrl(String url) {
StringBuilder str = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse response = client.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) { // Download OK
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
BufferedReader reader = new BufferedReader(
new InputStreamReader(content));
String line;
while ((line = reader.readLine()) != null) {
str.append(line);
}
} else {
Log.e("Log", "Failed to download file..");
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return str.toString();
}
/***** Get Image Resource from URL (Start) *****/
private static final String TAG = "Image";
private static final int IO_BUFFER_SIZE = 4 * 1024;
public static Bitmap loadBitmap(String url) {
Bitmap bitmap = null;
InputStream in = null;
BufferedOutputStream out = null;
try {
in = new BufferedInputStream(new URL(url).openStream(),
IO_BUFFER_SIZE);
final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);
copy(in, out);
out.flush();
final byte[] data = dataStream.toByteArray();
BitmapFactory.Options options = new BitmapFactory.Options();
// options.inSampleSize = 1;
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length,
options);
} catch (IOException e) {
Log.e(TAG, "Could not load Bitmap from: " + url);
} finally {
closeStream(in);
closeStream(out);
}
return bitmap;
}
private static void closeStream(Closeable stream) {
if (stream != null) {
try {
stream.close();
} catch (IOException e) {
android.util.Log.e(TAG, "Could not close stream", e);
}
}
}
private static void copy(InputStream in, OutputStream out)
throws IOException {
byte[] b = new byte[IO_BUFFER_SIZE];
int read;
while ((read = in.read(b)) != -1) {
out.write(b, 0, read);
}
}
}
問題是什麼？ –