我无法让我的搜索活动发挥作用。在堆栈上获得大量帮助后，我现在有一个带有操作栏的搜索活动，该操作栏可以执行搜索并向用户显示结果。
我的问题是，我根据我的帮助将所有功能写入一个类。现在我已经学到了很多东西，我意识到这不是最好的方法，我应该有自己的类，我不知道如何转移我的代码，轻松获取每个活动的操作栏，而无需添加所有代码对每一项活动。
以下是我的搜索活动目前的内容：
public class Search extends Activity implements OnQueryTextListener {
private ListView lv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d("logIN", "starting activity");
setContentView(R.layout.activity_search);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
SearchView searchView = (SearchView) menu.findItem(R.id.menu_search).getActionView();
searchView.setOnQueryTextListener(this);
return true;
}
//get entered search and pop up a toast to show query entered
public boolean onQueryTextSubmit (String query) {
//toast query
Toast.makeText(this, "Searching for: " + query + "...", Toast.LENGTH_SHORT).show();
//make json variables to fill
// url to make request
String url = "searchURLWillGoHere";
try {
query = URLEncoder.encode(query, "UTF-8");
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String jsonUrl = url + query;
//todo: get json
new ReadJSONResult().execute(jsonUrl);
return false;
}
public class ReadJSONResult extends AsyncTask
<String, Void, String> {
protected String doInBackground(String... urls) {
return readJSONFeed(urls[0]);
}
protected void onPostExecute(String result) {
try {
//start progress bar
//requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
//setProgressBarIndeterminateVisibility(true);
///get
JSONObject json = new JSONObject(result);
//acces listview
lv = (ListView) findViewById(android.R.id.list);
//make array list for beer
final List<BeerData> beerList = new ArrayList<BeerData>();
//get json items
for(int i = 0; i < json.getJSONArray("data").length(); i++) {
String beerId = GetBeerDataFromJSON(i,"id", json);
String beerName = GetBeerDataFromJSON(i,"name", json);
String beerDescription = GetBeerDataFromJSON(i,"description" , json);
String beerAbv = GetBeerDataFromJSON(i,"abv" , json);
String beerIbu = GetBeerDataFromJSON(i,"ibu" , json);
String beerIcon = GetBeerIconsFromJSON(i, "icon",json );
String beerMediumIcon = GetBeerIconsFromJSON(i, "medium",json );
String beerLargeIcon = GetBeerIconsFromJSON(i, "large",json );
String beerGlass = GetBeerGlassFromJSON(i, json );
String beerStyle = GetBeerStyleFromJSON(i,"name", json );
String beerStyleDescription = GetBeerStyleFromJSON(i,"description", json );
String beerBreweryId = GetBeerBreweryInfoFromJSON(i, "id", json );
String beerBreweryName = GetBeerBreweryInfoFromJSON(i, "name", json );
String beerBreweryDescription = GetBeerBreweryInfoFromJSON(i, "description", json );
String beerBreweryWebsite = GetBeerBreweryInfoFromJSON(i, "website", json );
//get long and latt
String beerBreweryLat = GetBeerBreweryLocationJSON(i, "longitude", json );
String beerBreweryLong = GetBeerBreweryLocationJSON(i, "latitude", json );
String beerBreweryYear = GetBeerBreweryInfoFromJSON(i, "established", json );
String beerBreweryIcon = GetBeerBreweryIconsFromJSON(i,"large",json);
//create beer object
BeerData thisBeer = new BeerData(beerName, beerId, beerDescription, beerAbv, beerIbu, beerIcon,
beerMediumIcon,beerLargeIcon, beerGlass, beerStyle, beerStyleDescription, beerBreweryId, beerBreweryName,
beerBreweryDescription, beerBreweryYear, beerBreweryWebsite,beerBreweryIcon, beerBreweryLat, beerBreweryLong);
//add beer to list
beerList.add(thisBeer);
}
//update listview
BeerSearchAdapter adapter1 = new BeerSearchAdapter(Search.this ,R.layout.listview_item_row, beerList);
lv.setAdapter(adapter1);
//set up clicks
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
Intent i = new Intent(Search.this, BeerPage.class);
BeerData beerInfo = beerList.get(arg2);
//Toast.makeText(MainActivity.this, beerInfo.beerName, Toast.LENGTH_SHORT).show();
i.putExtra("myBeerObject", beerInfo);
i.setClass(Search.this, BeerPage.class);
startActivity(i);
}
});
//end progress bar
//setProgressBarIndeterminateVisibility(false);
} catch (Exception e) {
Log.d("ReadBeerDataTask", e.getLocalizedMessage());
}
}
}
private String GetBeerDataFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get icons
private String GetBeerBreweryIconsFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONArray("breweries").getJSONObject(0).getJSONObject("images").getString(whatIsTheKeyYouAreLookFor);;
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get icons
private String GetBeerIconsFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONObject("labels").getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get style information
private String GetBeerStyleFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONObject("style").getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get location data
private String GetBeerBreweryLocationJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONArray("breweries").getJSONObject(0).getJSONArray("locations").getJSONObject(0).getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get brewery information
//get style information
private String GetBeerBreweryInfoFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONArray("breweries").getJSONObject(0).getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get glass
private String GetBeerGlassFromJSON(int position, JSONObject json ) {
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONObject("glass").getString("name");
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//gets the json from the inputed url
public String readJSONFeed(String URL) {
StringBuilder stringBuilder = new StringBuilder();
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(URL);
try {
HttpResponse response = httpClient.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream inputStream = entity.getContent();
BufferedReader reader = new BufferedReader(
new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
stringBuilder.append(line);
}
inputStream.close();
} else {
Log.d("JSON", "Failed to download file");
}
} catch (Exception e) {
Log.d("readJSONFeed", e.getLocalizedMessage());
}
return stringBuilder.toString();
}
@Override
public boolean onQueryTextChange(String newText) {
// TODO Auto-generated method stub
return false;
}
}
更新：我在评论中提出了建议并使用了我的search.java并转到了我的beerPage并进行了扩展搜索：
public class BeerPage extends Search
我现在可以在BeerPage上进行搜索，但是当我尝试执行搜索时，它强制关闭此错误：
06-30 10:13:16.357: E/AndroidRuntime(22194): FATAL EXCEPTION: main
06-30 10:13:16.357: E/AndroidRuntime(22194): java.lang.NullPointerException: println needs a message
06-30 10:13:16.357: E/AndroidRuntime(22194): at android.util.Log.println_native(Native Method)
06-30 10:13:16.357: E/AndroidRuntime(22194): at android.util.Log.d(Log.java:138)
06-30 10:13:16.357: E/AndroidRuntime(22194): at com.example.beerportfoliopro.Search$ReadJSONResult.onPostExecute(Search.java:196)
06-30 10:13:16.357: E/AndroidRuntime(22194): at com.example.beerportfoliopro.Search$ReadJSONResult.onPostExecute(Search.java:1)
06-30 10:13:16.357: E/AndroidRuntime(22194): at android.os.AsyncTask.finish(AsyncTask.java:631)
06-30 10:13:16.357: E/AndroidRuntime(22194): at android.os.AsyncTask.access$600(AsyncTask.java:177)
06-30 10:13:16.357: E/AndroidRuntime(22194): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
06-30 10:13:16.357: E/AndroidRuntime(22194): at android.os.Handler.dispatchMessage(Handler.java:99)
06-30 10:13:16.357: E/AndroidRuntime(22194): at android.os.Looper.loop(Looper.java:155)
06-30 10:13:16.357: E/AndroidRuntime(22194): at android.app.ActivityThread.main(ActivityThread.java:5536)
06-30 10:13:16.357: E/AndroidRuntime(22194): at java.lang.reflect.Method.invokeNative(Native Method)
06-30 10:13:16.357: E/AndroidRuntime(22194): at java.lang.reflect.Method.invoke(Method.java:511)
06-30 10:13:16.357: E/AndroidRuntime(22194): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1074)
06-30 10:13:16.357: E/AndroidRuntime(22194): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:841)
06-30 10:13:16.357: E/AndroidRuntime(22194): at dalvik.system.NativeStart.main(Native Method)
我认为问题是啤酒页面没有列表视图，但搜索页面确实如此。我可以将其更改为搜索页面以显示啤酒页面搜索的结果吗？