在android上从asyncTask获取java.util.concurrent.RejectedExecutionException
我正在将sqlite数据库读入tableLayout。我不想在一个单独的线程中执行此操作，而不是在没有ui更新的情况下等待很长时间。因此，我使用AsyncTask来完成一些工作并发布结果。然而，在我的列表中，只有大约1/4的项目真正进入了TableLayout。它在没有异步任务的情况下运行良好。列表中的大多数项都会抛出一个错误（我发现了），java.util.concurrent.RejectedExecutionException。我不知道这是为什么。这是我的密码在android上从asyncTask获取java.util.concurrent.RejectedExecutionException,android,xml,multithreading,layout,android-asynctask,Android,Xml,Multithreading,Layout,Android Asynctask,我正在将sqlite数据库读入tableLayout。我不想在一个单独的线程中执行此操作，而不是在没有ui更新的情况下等待很长时间。因此，我使用AsyncTask来完成一些工作并发布结果。然而，在我的列表中，只有大约1/4的项目真正进入了TableLayout。它在没有异步任务的情况下运行良好。列表中的大多数项都会抛出一个错误（我发现了），java.util.concurrent.RejectedExecutionException。我不知道这是为什么。这是我的密码 myDB.execSQL("
myDB.execSQL("CREATE TABLE IF NOT EXISTS "
+ TableName
+ " (_id INTEGER PRIMARY KEY, filepath TEXT UNIQUE, title TEXT, artist TEXT, album TEXT, time TEXT, playcount NUMERIC);");
Cursor c = myDB.rawQuery("SELECT * FROM " + TableName, null);
c.moveToFirst();
if (c != null) {
int color = 0xFFdfe8ea;
this.startManagingCursor(c);
// Loop through all Results
do {
try{
MyAsyncTask aTask = new MyAsyncTask();
String[]strings= {c.getString(c.getColumnIndex("title")),c.getString(c.getColumnIndex("artist")),c.getString(c.getColumnIndex("time")),c.getString(c.getColumnIndex("album")),""+color};
aTask.execute(strings);
}catch(Exception e){
Log.w("****", e);
}
if (color == 0xFFdfe8ea) {
color = 0xFFf2f8fa;
} else {
color = 0xFFdfe8ea;
}
} while (c.moveToNext());
}
} catch (SQLException e) {
Log.e("****", e.toString());
} finally {
if (myDB != null) {
myDB.close();
}
}
class MyAsyncTask extends AsyncTask<String, Void, View> {
@Override
protected View doInBackground(String... params) {
int color = Integer.parseInt(params[4]);
TableRow tr = new TableRow(MainActivity.this);
tr.setLayoutParams(new LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
TextView space = new TextView(MainActivity.this);
space.setText("");
space.setBackgroundColor(color); //0xFFf2f8fa alternating
space.setSingleLine();
space.setPadding(2, 2, 2, 2);
space.setGravity(Gravity.LEFT);
space.setTextColor(0xFF000000);
space.setLayoutParams(new LayoutParams(
findViewById(R.id.spaceColumn).getWidth(),
LayoutParams.WRAP_CONTENT));
/* Create a Button to be the row-content. */
TextView title = new TextView(MainActivity.this);
title.setText(params[0]);
title.setBackgroundColor(color); //0xFFf2f8fa alternating
title.setSingleLine();
title.setPadding(2, 2, 2, 2);
title.setGravity(Gravity.LEFT);
title.setTextColor(0xFF000000);
title.setEllipsize(TruncateAt.END);
title.setLayoutParams(new LayoutParams(
0,
LayoutParams.WRAP_CONTENT, 1));
/* Create a Button to be the row-content. */
TextView artist = new TextView(MainActivity.this);
artist.setText(params[1]);
artist.setBackgroundColor(color); //0xFFf2f8fa alternating
artist.setSingleLine();
artist.setPadding(2, 2, 2, 2);
artist.setGravity(Gravity.LEFT);
artist.setTextColor(0xFF000000);
artist.setEllipsize(TruncateAt.END);
artist.setLayoutParams(new LayoutParams(
0,
LayoutParams.WRAP_CONTENT, 1));
/* Create a Button to be the row-content. */
TextView time = new TextView(MainActivity.this);
time.setText(params[2]);
time.setBackgroundColor(color); //0xFFf2f8fa alternating
time.setSingleLine();
time.setPadding(2, 2, 2, 2);
time.setGravity(Gravity.LEFT);
time.setTextColor(0xFF000000);
time.setLayoutParams(new LayoutParams(
findViewById(R.id.timeColumn).getWidth(),
LayoutParams.WRAP_CONTENT));
/* Create a Button to be the row-content. */
TextView album = new TextView(MainActivity.this);
album.setText(params[3]);
album.setBackgroundColor(color); //0xFFf2f8fa alternating
album.setSingleLine();
album.setPadding(2, 2, 2, 2);
album.setGravity(Gravity.LEFT);
album.setTextColor(0xFF000000);
album.setEllipsize(TruncateAt.END);
album.setLayoutParams(new LayoutParams(
0,
LayoutParams.WRAP_CONTENT, 1));
/* Add Button to row. */
tr.addView(space);
tr.addView(title);
tr.addView(artist);
tr.addView(time);
tr.addView(album);
/* Add row to TableLayout. */
return tr;
}
@Override
protected void onPostExecute(View tr) {
((TableLayout) findViewById(R.id.tableLayout)).addView(tr, new TableLayout.LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
}
@Override
protected void onPreExecute() {
}
}
作为参考，这是我如何修复它的
class MyAsyncTask extends AsyncTask<Void, Song, Void> {
@Override
protected Void doInBackground(Void... params) {
SQLiteDatabase myDB = openOrCreateDatabase("DatabaseName", MODE_PRIVATE, null);
String TableName = "songs";
myDB.execSQL("CREATE TABLE IF NOT EXISTS "
+ TableName
+ " (_id INTEGER PRIMARY KEY, filepath TEXT UNIQUE, title TEXT, artist TEXT, album TEXT, time TEXT, playcount NUMERIC);");
Cursor c = myDB.rawQuery("SELECT * FROM " + TableName, null);
c.moveToFirst();
int filepathIndex=c.getColumnIndex("filepath");
int titleIndex=c.getColumnIndex("title");
int artistIndex=c.getColumnIndex("artist");
int albumIndex=c.getColumnIndex("album");
int timeIndex=c.getColumnIndex("time");
int playcountIndex=c.getColumnIndex("playcount");
if (c != null) {
int color = 0xFFdfe8ea;
// this.startManagingCursor(c);
// Loop through all Results
do {
Song song = new Song(c.getString(filepathIndex),c.getString(titleIndex),c.getString(artistIndex),c.getString(albumIndex),c.getString(timeIndex),c.getInt(playcountIndex),color);
// Add to song the data from your cursor
publishProgress(song);
if (color == 0xFFdfe8ea) {
color = 0xFFf2f8fa;
} else {
color = 0xFFdfe8ea;
}
} while (c.moveToNext());
}
return null;
}
@Override
protected void onPostExecute(Void item) {
}
@Override
protected void onPreExecute() {
}
@Override
protected void onProgressUpdate(Song... items) {
for (Song song : items) {
TableRow tr = new TableRow(MainActivity.this);
tr.setLayoutParams(new LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
TextView space = new TextView(MainActivity.this);
space.setText("");
space.setBackgroundColor(song.color); //0xFFf2f8fa alternating
space.setSingleLine();
space.setPadding(2, 2, 2, 2);
space.setGravity(Gravity.LEFT);
space.setTextColor(0xFF000000);
space.setLayoutParams(new LayoutParams(
findViewById(R.id.spaceColumn).getWidth(),
LayoutParams.WRAP_CONTENT));
/* Create a Button to be the row-content. */
TextView title = new TextView(MainActivity.this);
title.setText(song.title);
title.setBackgroundColor(song.color); //0xFFf2f8fa alternating
title.setSingleLine();
title.setPadding(2, 2, 2, 2);
title.setGravity(Gravity.LEFT);
title.setTextColor(0xFF000000);
title.setEllipsize(TruncateAt.END);
title.setLayoutParams(new LayoutParams(
0,
LayoutParams.WRAP_CONTENT, 1));
/* Create a Button to be the row-content. */
TextView artist = new TextView(MainActivity.this);
artist.setText(song.artist);
artist.setBackgroundColor(song.color); //0xFFf2f8fa alternating
artist.setSingleLine();
artist.setPadding(2, 2, 2, 2);
artist.setGravity(Gravity.LEFT);
artist.setTextColor(0xFF000000);
artist.setEllipsize(TruncateAt.END);
artist.setLayoutParams(new LayoutParams(
0,
LayoutParams.WRAP_CONTENT, 1));
/* Create a Button to be the row-content. */
TextView time = new TextView(MainActivity.this);
time.setText(song.time);
time.setBackgroundColor(song.color); //0xFFf2f8fa alternating
time.setSingleLine();
time.setPadding(2, 2, 2, 2);
time.setGravity(Gravity.LEFT);
time.setTextColor(0xFF000000);
time.setLayoutParams(new LayoutParams(
findViewById(R.id.timeColumn).getWidth(),
LayoutParams.WRAP_CONTENT));
/* Create a Button to be the row-content. */
TextView album = new TextView(MainActivity.this);
album.setText(song.album);
album.setBackgroundColor(song.color); //0xFFf2f8fa alternating
album.setSingleLine();
album.setPadding(2, 2, 2, 2);
album.setGravity(Gravity.LEFT);
album.setTextColor(0xFF000000);
album.setEllipsize(TruncateAt.END);
album.setLayoutParams(new LayoutParams(
0,
LayoutParams.WRAP_CONTENT, 1));
/* Add Button to row. */
tr.addView(space);
tr.addView(title);
tr.addView(artist);
tr.addView(time);
tr.addView(album);
// Add the row to the table
((TableLayout) findViewById(R.id.tableLayout)).addView(tr, new TableLayout.LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
}
}
}
public class MyAdapter extends BaseAdapter {
private Context context = null;
private Cursor cursor;
public MyAdapter(Context context){
this.context = context;
SQLiteDatabase db = DatabaseHelper.getInstance(context).getReadableDatabase();
this.cursor = db.query("YOUR QUERY");
}
@Override
public int getCount() {
return this.cursor.getCount();
}
public Cursor getCursor() {
return cursor;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LinearLayout row;
try {
cursor.moveToPosition(position);
if (convertView == null) {
row = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.myRowLayout, parent, false);
} else {
row = (LinearLayout) convertView;
}
TextView name = (TextView) row.findViewById(R.id.myLayoutId);
name.setText(cursor.getString(cursor.getColumnIndex("your column")));
} catch (Exception e) {
row = null;
Log.e(LOG_TAG, "" + e.getMessage());
e.printStackTrace();
}
return row;
}
@Override
public MoneyCurrency getItem(int position) {
this.cursor.moveToPosition(position);
long id = this.cursor.getLong(this.cursor.getColumnIndex("your column id"));
return new Object.read(id, context, null); //Return whatever you want to show in that row. This is used if you want to use onClick listeners or menus
}
@Override
public long getItemId(int position) {
this.cursor.moveToPosition(position);
return this.cursor.getLong(this.cursor.getColumnIndex("your id column"));
}
}
class MyAsyncTask extends AsyncTask<Void, Song, Void> {
@Override
protected Void doInBackground(Void... params) {
myDB.execSQL("CREATE TABLE IF NOT EXISTS "
+ TableName
+ " (_id INTEGER PRIMARY KEY, filepath TEXT UNIQUE, title TEXT, artist TEXT, album TEXT, time TEXT, playcount NUMERIC);");
Cursor c = myDB.rawQuery("SELECT * FROM " + TableName, null);
c.moveToFirst();
if (c != null) {
int color = 0xFFdfe8ea;
this.startManagingCursor(c);
// Loop through all Results
do {
Song song = new Song();
// Add to song the data from your cursor
publishProgress(song);
} while (c.moveToNext());
}
return null;
}
@Override
protected void onPostExecute(Void item) {
}
@Override
protected void onPreExecute() {
}
@Override
protected void onProgressUpdate(Song... items) {
for (Song song : items) {
TableRow tr = new TableRow(MainActivity.this);
tr.setLayoutParams(new LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
TextView space = new TextView(MainActivity.this);
space.setText("");
space.setBackgroundColor(color); //0xFFf2f8fa alternating
space.setSingleLine();
space.setPadding(2, 2, 2, 2);
space.setGravity(Gravity.LEFT);
space.setTextColor(0xFF000000);
space.setLayoutParams(new LayoutParams(
findViewById(R.id.spaceColumn).getWidth(),
LayoutParams.WRAP_CONTENT));
/* Create a Button to be the row-content. */
TextView title = new TextView(MainActivity.this);
title.setText(song.getTitle());
title.setBackgroundColor(color); //0xFFf2f8fa alternating
title.setSingleLine();
title.setPadding(2, 2, 2, 2);
title.setGravity(Gravity.LEFT);
title.setTextColor(0xFF000000);
title.setEllipsize(TruncateAt.END);
title.setLayoutParams(new LayoutParams(
0,
LayoutParams.WRAP_CONTENT, 1));
/* Create a Button to be the row-content. */
TextView artist = new TextView(MainActivity.this);
artist.setText(song.getArtist());
artist.setBackgroundColor(color); //0xFFf2f8fa alternating
artist.setSingleLine();
artist.setPadding(2, 2, 2, 2);
artist.setGravity(Gravity.LEFT);
artist.setTextColor(0xFF000000);
artist.setEllipsize(TruncateAt.END);
artist.setLayoutParams(new LayoutParams(
0,
LayoutParams.WRAP_CONTENT, 1));
/* Create a Button to be the row-content. */
TextView time = new TextView(MainActivity.this);
time.setText(song.getTime());
time.setBackgroundColor(color); //0xFFf2f8fa alternating
time.setSingleLine();
time.setPadding(2, 2, 2, 2);
time.setGravity(Gravity.LEFT);
time.setTextColor(0xFF000000);
time.setLayoutParams(new LayoutParams(
findViewById(R.id.timeColumn).getWidth(),
LayoutParams.WRAP_CONTENT));
/* Create a Button to be the row-content. */
TextView album = new TextView(MainActivity.this);
album.setText(song.getAlbum());
album.setBackgroundColor(color); //0xFFf2f8fa alternating
album.setSingleLine();
album.setPadding(2, 2, 2, 2);
album.setGravity(Gravity.LEFT);
album.setTextColor(0xFF000000);
album.setEllipsize(TruncateAt.END);
album.setLayoutParams(new LayoutParams(
0,
LayoutParams.WRAP_CONTENT, 1));
/* Add Button to row. */
tr.addView(space);
tr.addView(title);
tr.addView(artist);
tr.addView(time);
tr.addView(album);
// Add the row to the table
((TableLayout) findViewById(R.id.tableLayout)).addView(tr, new TableLayout.LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
}
}
}
private static final int CORE_POOL_SIZE = 5;
private static final int MAXIMUM_POOL_SIZE = 128;
private static final int KEEP_ALIVE = 1;
private static final BlockingQueue<Runnable> sPoolWorkQueue =
new LinkedBlockingQueue<Runnable>(10);
/**
* An {@link Executor} that can be used to execute tasks in parallel.
*/
public static final Executor THREAD_POOL_EXECUTOR
= new ThreadPoolExecutor(CORE_POOL_SIZE, MAXIMUM_POOL_SIZE, KEEP_ALIVE,
TimeUnit.SECONDS, sPoolWorkQueue, sThreadFactory);