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Code Issues Actions Packages Projects Releases Wiki Activity

Use AsyncTask instead of Thread for cleaner async work handling

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git-svn-id: https://zxing.googlecode.com/svn/trunk@2369 59b500cc-1b3d-0410-9834-0bbf25fbcc57
This commit is contained in:
srowen 2012-08-06 10:22:55 +00:00
parent 9e815a73b7
commit 12c113004d
3 changed files with 115 additions and 167 deletions
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5
android/src/com/google/zxing/client/android/HttpHelper.java
View file

@ -16,6 +16,8 @@
package com.google.zxing.client.android;
import android.util.Log;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
@ -35,6 +37,8 @@ import java.util.HashSet;
*/
public final class HttpHelper {
private static final String TAG = HttpHelper.class.getSimpleName();
private static final Collection<String> REDIRECTOR_DOMAINS = new HashSet<String>(Arrays.asList(
"amzn.to", "bit.ly", "bitly.com", "fb.me", "goo.gl", "is.gd", "j.mp", "lnkd.in", "ow.ly",
"R.BEETAGG.COM", "r.beetagg.com", "SCN.BY", "su.pr", "t.co", "tinyurl.com", "tr.im"
@ -75,6 +79,7 @@ public final class HttpHelper {
}
private static String downloadViaHttp(String uri, String contentTypes) throws IOException {
Log.i(TAG, "Downloading " + uri);
URL url = new URL(uri);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestProperty("Accept", contentTypes);

76
android/src/com/google/zxing/client/android/book/NetworkWorker.java
View file

@ -1,76 +0,0 @@
/*
* Copyright (C) 2010 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.zxing.client.android.book;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import com.google.zxing.client.android.HttpHelper;
import com.google.zxing.client.android.LocaleManager;
import com.google.zxing.client.android.R;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
final class NetworkWorker implements Runnable {
private static final String TAG = NetworkWorker.class.getSimpleName();
private final String isbn;
private final String query;
private final Handler handler;
NetworkWorker(String isbn, String query, Handler handler) {
this.isbn = isbn;
this.query = query;
this.handler = handler;
}
@Override
public void run() {
try {
// These return a JSON result which describes if and where the query was found. This API may
// break or disappear at any time in the future. Since this is an API call rather than a
// website, we don't use LocaleManager to change the TLD.
String uri;
if (LocaleManager.isBookSearchUrl(isbn)) {
int equals = isbn.indexOf('=');
String volumeId = isbn.substring(equals + 1);
uri = "http://www.google.com/books?id=" + volumeId + "&jscmd=SearchWithinVolume2&q=" + query;
} else {
uri = "http://www.google.com/books?vid=isbn" + isbn + "&jscmd=SearchWithinVolume2&q=" + query;
}
try {
String content = HttpHelper.downloadViaHttp(uri, HttpHelper.ContentType.JSON);
JSONObject json = new JSONObject(content);
Message message = Message.obtain(handler, R.id.search_book_contents_succeeded);
message.obj = json;
message.sendToTarget();
} catch (IOException ioe) {
Message message = Message.obtain(handler, R.id.search_book_contents_failed);
message.sendToTarget();
}
} catch (JSONException je) {
Log.w(TAG, "Error accessing book search", je);
Message message = Message.obtain(handler, R.id.search_book_contents_failed);
message.sendToTarget();
}
}
}

201
android/src/com/google/zxing/client/android/book/SearchBookContentsActivity.java
View file

@ -18,9 +18,8 @@ package com.google.zxing.client.android.book;
import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.KeyEvent;
import android.view.LayoutInflater;
@ -31,10 +30,12 @@ import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import com.google.zxing.client.android.HttpHelper;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
@ -58,29 +59,12 @@ public final class SearchBookContentsActivity extends Activity {
private static final Pattern QUOTE_ENTITY_PATTERN = Pattern.compile("&#39;");
private static final Pattern QUOT_ENTITY_PATTERN = Pattern.compile("&quot;");
private Thread networkThread;
private String isbn;
private EditText queryTextView;
private Button queryButton;
private ListView resultListView;
private TextView headerView;
private final Handler handler = new Handler() {
@Override
public void handleMessage(Message message) {
switch (message.what) {
case R.id.search_book_contents_succeeded:
handleSearchResults((JSONObject) message.obj);
resetForNewQuery();
break;
case R.id.search_book_contents_failed:
resetForNewQuery();
headerView.setText(R.string.msg_sbc_failed);
break;
}
}
};
private final Button.OnClickListener buttonListener = new Button.OnClickListener() {
@Override
public void onClick(View view) {
@ -150,86 +134,121 @@ public final class SearchBookContentsActivity extends Activity {
queryTextView.selectAll();
}
private void resetForNewQuery() {
networkThread = null;
queryTextView.setEnabled(true);
queryTextView.selectAll();
queryButton.setEnabled(true);
}
private void launchSearch() {
if (networkThread == null) {
String query = queryTextView.getText().toString();
if (query != null && query.length() > 0) {
networkThread = new Thread(new NetworkWorker(isbn, query, handler));
networkThread.start();
headerView.setText(R.string.msg_sbc_searching_book);
resultListView.setAdapter(null);
queryTextView.setEnabled(false);
queryButton.setEnabled(false);
}
}
}
// Currently there is no way to distinguish between a query which had no results and a book
// which is not searchable - both return zero results.
private void handleSearchResults(JSONObject json) {
try {
int count = json.getInt("number_of_results");
headerView.setText(getString(R.string.msg_sbc_results) + " : " + count);
if (count > 0) {
JSONArray results = json.getJSONArray("search_results");
SearchBookContentsResult.setQuery(queryTextView.getText().toString());
List<SearchBookContentsResult> items = new ArrayList<SearchBookContentsResult>(count);
for (int x = 0; x < count; x++) {
items.add(parseResult(results.getJSONObject(x)));
}
resultListView.setOnItemClickListener(new BrowseBookListener(this, items));
resultListView.setAdapter(new SearchBookContentsAdapter(this, items));
} else {
String searchable = json.optString("searchable");
if ("false".equals(searchable)) {
headerView.setText(R.string.msg_sbc_book_not_searchable);
}
resultListView.setAdapter(null);
}
} catch (JSONException e) {
Log.w(TAG, "Bad JSON from book search", e);
String query = queryTextView.getText().toString();
if (query != null && query.length() > 0) {
NetworkTask networkTask = new NetworkTask();
networkTask.execute(query, isbn);
headerView.setText(R.string.msg_sbc_searching_book);
resultListView.setAdapter(null);
headerView.setText(R.string.msg_sbc_failed);
queryTextView.setEnabled(false);
queryButton.setEnabled(false);
}
}
// Available fields: page_id, page_number, page_url, snippet_text
private SearchBookContentsResult parseResult(JSONObject json) {
try {
String pageId = json.getString("page_id");
String pageNumber = json.getString("page_number");
if (pageNumber.length() > 0) {
pageNumber = getString(R.string.msg_sbc_page) + ' ' + pageNumber;
} else {
// This can happen for text on the jacket, and possibly other reasons.
pageNumber = getString(R.string.msg_sbc_unknown_page);
}
private final class NetworkTask extends AsyncTask<String,Object,JSONObject> {
// Remove all HTML tags and encoded characters. Ideally the server would do this.
String snippet = json.optString("snippet_text");
boolean valid = true;
if (snippet.length() > 0) {
snippet = TAG_PATTERN.matcher(snippet).replaceAll("");
snippet = LT_ENTITY_PATTERN.matcher(snippet).replaceAll("<");
snippet = GT_ENTITY_PATTERN.matcher(snippet).replaceAll(">");
snippet = QUOTE_ENTITY_PATTERN.matcher(snippet).replaceAll("'");
snippet = QUOT_ENTITY_PATTERN.matcher(snippet).replaceAll("\"");
} else {
snippet = '(' + getString(R.string.msg_sbc_snippet_unavailable) + ')';
valid = false;
@Override
protected JSONObject doInBackground(String... args) {
try {
// These return a JSON result which describes if and where the query was found. This API may
// break or disappear at any time in the future. Since this is an API call rather than a
// website, we don't use LocaleManager to change the TLD.
String theQuery = args[0];
String theIsbn = args[1];
String uri;
if (LocaleManager.isBookSearchUrl(theIsbn)) {
int equals = theIsbn.indexOf('=');
String volumeId = theIsbn.substring(equals + 1);
uri = "http://www.google.com/books?id=" + volumeId + "&jscmd=SearchWithinVolume2&q=" + theQuery;
} else {
uri = "http://www.google.com/books?vid=isbn" + theIsbn + "&jscmd=SearchWithinVolume2&q=" + theQuery;
}
String content = HttpHelper.downloadViaHttp(uri, HttpHelper.ContentType.JSON);
return new JSONObject(content);
} catch (IOException ioe) {
Log.w(TAG, "Error accessing book search", ioe);
return null;
} catch (JSONException je) {
Log.w(TAG, "Error accessing book search", je);
return null;
}
return new SearchBookContentsResult(pageId, pageNumber, snippet, valid);
} catch (JSONException e) {
// Never seen in the wild, just being complete.
return new SearchBookContentsResult(getString(R.string.msg_sbc_no_page_returned), "", "", false);
}
@Override
protected void onPostExecute(JSONObject result) {
if (result == null) {
headerView.setText(R.string.msg_sbc_failed);
} else {
handleSearchResults(result);
}
queryTextView.setEnabled(true);
queryTextView.selectAll();
queryButton.setEnabled(true);
}
// Currently there is no way to distinguish between a query which had no results and a book
// which is not searchable - both return zero results.
private void handleSearchResults(JSONObject json) {
try {
int count = json.getInt("number_of_results");
headerView.setText(getString(R.string.msg_sbc_results) + " : " + count);
if (count > 0) {
JSONArray results = json.getJSONArray("search_results");
SearchBookContentsResult.setQuery(queryTextView.getText().toString());
List<SearchBookContentsResult> items = new ArrayList<SearchBookContentsResult>(count);
for (int x = 0; x < count; x++) {
items.add(parseResult(results.getJSONObject(x)));
}
resultListView.setOnItemClickListener(new BrowseBookListener(SearchBookContentsActivity.this, items));
resultListView.setAdapter(new SearchBookContentsAdapter(SearchBookContentsActivity.this, items));
} else {
String searchable = json.optString("searchable");
if ("false".equals(searchable)) {
headerView.setText(R.string.msg_sbc_book_not_searchable);
}
resultListView.setAdapter(null);
}
} catch (JSONException e) {
Log.w(TAG, "Bad JSON from book search", e);
resultListView.setAdapter(null);
headerView.setText(R.string.msg_sbc_failed);
}
}
// Available fields: page_id, page_number, page_url, snippet_text
private SearchBookContentsResult parseResult(JSONObject json) {
try {
String pageId = json.getString("page_id");
String pageNumber = json.getString("page_number");
if (pageNumber.length() > 0) {
pageNumber = getString(R.string.msg_sbc_page) + ' ' + pageNumber;
} else {
// This can happen for text on the jacket, and possibly other reasons.
pageNumber = getString(R.string.msg_sbc_unknown_page);
}
// Remove all HTML tags and encoded characters. Ideally the server would do this.
String snippet = json.optString("snippet_text");
boolean valid = true;
if (snippet.length() > 0) {
snippet = TAG_PATTERN.matcher(snippet).replaceAll("");
snippet = LT_ENTITY_PATTERN.matcher(snippet).replaceAll("<");
snippet = GT_ENTITY_PATTERN.matcher(snippet).replaceAll(">");
snippet = QUOTE_ENTITY_PATTERN.matcher(snippet).replaceAll("'");
snippet = QUOT_ENTITY_PATTERN.matcher(snippet).replaceAll("\"");
} else {
snippet = '(' + getString(R.string.msg_sbc_snippet_unavailable) + ')';
valid = false;
}
return new SearchBookContentsResult(pageId, pageNumber, snippet, valid);
} catch (JSONException e) {
// Never seen in the wild, just being complete.
return new SearchBookContentsResult(getString(R.string.msg_sbc_no_page_returned), "", "", false);
}
}
}
}