package com.example.asyncloadertest;
import java.io.FileDescriptor;
import java.io.IOException;
import java.io.PrintWriter;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import android.content.Context;
import android.support.v4.content.AsyncTaskLoader;
public class TestLoader extends AsyncTaskLoader<String> {
String result;
public TestLoader(Context context) {
super(context);
}
@Override
public String loadInBackground() {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet get = new HttpGet("http://www.yahoo.co.jp/");
try {
HttpResponse execute = client.execute(get);
String res = EntityUtils.toString(execute.getEntity());
return res;
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
public void deliverResult(String data) {
if (isReset()) {
if (this.result != null) {
this.result = null;
}
return;
}
this.result = data;
if (isStarted()) {
super.deliverResult(data);
}
}
@Override
protected void onStartLoading() {
if (this.result != null) {
deliverResult(this.result);
}
if (takeContentChanged() || this.result == null) {
// これをやっておくとonCreateLoaderで開始処理をしなくてよくなる
forceLoad();
}
}
@Override
protected void onStopLoading() {
super.onStopLoading();
cancelLoad();
}
@Override
protected void onReset() {
super.onReset();
onStopLoading();
}
@Override
public void dump(String prefix, FileDescriptor fd, PrintWriter writer,
String[] args) {
super.dump(prefix, fd, writer, args);
writer.print(prefix);
writer.print("result=");
writer.println(this.result);
}
}
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package com.example.asyncloadertest;
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.util.HashMap;
import android.os.Bundle;
import android.app.Activity;
import android.support.v4.app.LoaderManager;
import android.support.v4.app.LoaderManager.LoaderCallbacks;
import android.support.v4.content.Loader;
import android.util.Log;
import android.view.Menu;
import android.widget.TextView;
public class AsyncTascLoaderTestActivity extends Activity implements LoaderCallbacks<String> {
// Yahooをロードする
public static final int TASK_001 = 0x00001;
LoaderManager loaderManager = new LoaderManager() {
HashMap<Integer, Loader<String>> loaders = new HashMap<Integer, Loader<String>>();
@Override
public <String> Loader<String> restartLoader(int arg0, Bundle arg1,
LoaderCallbacks<String> arg2) {
return null;
}
/**
* ローダの初期化
*/
@Override
public <String> Loader<String> initLoader(int arg0, Bundle arg1,
LoaderCallbacks<String> arg2) {
Log.d("Called","initLoader");
Loader<String> loader = arg2.onCreateLoader(arg0, arg1);
// do initialize...
loaders.put(arg0, (Loader<String>) loader);
return loader;
}
@Override
public <String> Loader<String> getLoader(int arg0) {
Log.d("Called","getLoader");
return (Loader<String>) loaders.get(arg0);
}
@Override
public void dump(String arg0, FileDescriptor arg1, PrintWriter arg2,
String[] arg3) {
// nothing
}
/**
* 破棄
* これより前にロードを止めるべき
*/
@Override
public void destroyLoader(int arg0) {
Log.d("Called","destroyLoader");
loaders.remove(arg0);
}
};
// TextView
TextView view;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_async_tasc_loader_test);
// ローダー初期化
loaderManager.initLoader(TASK_001, null, this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.async_tasc_loader_test, menu);
return true;
}
/**
* ローダー作成
*/
@Override
public Loader<String> onCreateLoader(int arg0, Bundle arg1) {
Log.d("Called","onCreateLoader");
// Create
TestLoader loader = new TestLoader(this);
return loader;
}
/**
* バックグラウンド処理が終わったら
*/
@Override
public void onLoadFinished(Loader<String> arg0, String arg1) {
Log.d("Called","onLoadFinished");
view = (TextView) findViewById(R.id.view);
if (arg0 != null && arg0.getId() == TASK_001) {
view.setText(arg1);
}
}
/**
* 処理がリセットされたら
*/
@Override
public void onLoaderReset(Loader<String> arg0) {
if (view != null)
view.setText("Loader is reset");
}
}
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