在我的 Android 应用程序中，我有一个 EditText、一个 Button 和一个 Listview。当我在 EditText 字段中输入电影名称并按下 Button 时，我希望在 ListView 中填充与我在 EditText 字段中输入的内容匹配的烂番茄网站上的电影名称。
但我不知道如何使用Rotten Tomatoes JSON API 来获取电影数据。我该怎么做？
【问题讨论】：
标签： android json httprequest httpclient rotten-tomatoes
基本上，你需要做四件事：
http://api.rottentomatoes.com/api/public/v1.0/movies.json?apikey=[your_api_key]&q=[search_keyword]&page_limit=[page_limit]，如this 页面所示。我已经制作了一个小型演示应用程序来执行此操作。请尝试以下代码。
MainActivity.java
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
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 java.io.ByteArrayOutputStream;
import java.io.IOException;
public class MainActivity extends Activity
{
// the Rotten Tomatoes API key of your application! get this from their website
private static final String API_KEY = <your api key!>;
// the number of movies you want to get in a single request to their web server
private static final int MOVIE_PAGE_LIMIT = 10;
private EditText searchBox;
private Button searchButton;
private ListView moviesList;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
searchBox = (EditText) findViewById(R.id.text_search_box);
searchButton = (Button) findViewById(R.id.button_search);
searchButton.setOnClickListener(new OnClickListener()
{
// send an API request when the button is pressed
@Override
public void onClick(View arg0)
{
new RequestTask().execute("http://api.rottentomatoes.com/api/public/v1.0/movies.json?apikey=" + API_KEY + "&q=" + searchBox.getText().toString().trim() + "&page_limit=" + MOVIE_PAGE_LIMIT);
}
});
moviesList = (ListView) findViewById(R.id.list_movies);
}
private void refreshMoviesList(String[] movieTitles)
{
moviesList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, movieTitles));
}
private class RequestTask extends AsyncTask<String, String, String>
{
// make a request to the specified url
@Override
protected String doInBackground(String... uri)
{
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response;
String responseString = null;
try
{
// make a HTTP request
response = httpclient.execute(new HttpGet(uri[0]));
StatusLine statusLine = response.getStatusLine();
if (statusLine.getStatusCode() == HttpStatus.SC_OK)
{
// request successful - read the response and close the connection
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
out.close();
responseString = out.toString();
}
else
{
// request failed - close the connection
response.getEntity().getContent().close();
throw new IOException(statusLine.getReasonPhrase());
}
}
catch (Exception e)
{
Log.d("Test", "Couldn't make a successful request!");
}
return responseString;
}
// if the request above completed successfully, this method will
// automatically run so you can do something with the response
@Override
protected void onPostExecute(String response)
{
super.onPostExecute(response);
if (response != null)
{
try
{
// convert the String response to a JSON object,
// because JSON is the response format Rotten Tomatoes uses
JSONObject jsonResponse = new JSONObject(response);
// fetch the array of movies in the response
JSONArray movies = jsonResponse.getJSONArray("movies");
// add each movie's title to an array
String[] movieTitles = new String[movies.length()];
for (int i = 0; i < movies.length(); i++)
{
JSONObject movie = movies.getJSONObject(i);
movieTitles[i] = movie.getString("title");
}
// update the UI
refreshMoviesList(movieTitles);
}
catch (JSONException e)
{
Log.d("Test", "Failed to parse the JSON response!");
}
}
}
}
}
res/layouts/activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#E9E9E9"
android:focusable="true"
android:focusableInTouchMode="true"
android:orientation="horizontal"
android:padding="3dip" >
<EditText
android:id="@+id/text_search_box"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1.0"
android:gravity="center" />
<Button
android:id="@+id/button_search"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:drawableRight="@android:drawable/ic_search_category_default" />
</LinearLayout>
<ListView
android:id="@+id/list_movies"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_weight="1.0" />
</LinearLayout>
并将这一行添加到您的AndroidManifest.xml（它授予您的 Android 应用程序使用互联网的权限，您显然需要向 Rotten Tomatoes 的网络服务器发出请求）：
<uses-permission android:name="android.permission.INTERNET" />
奖励答案：
如果您想在 EditText 字段中键入搜索关键字时获得“实时”搜索结果，请通过 EditText 的 addTextChangedListener() 方法添加一个 TextWatcher，并使其在 onTextChanged() 中执行 HTTP 请求。
【讨论】：
解决此类问题的典型方法是：
创建一个AsyncTask 来处理您的请求和响应的网络和解析，因为在主（或 UI）线程中长时间运行操作是一个坏主意。在 AsyncTask 中，您使用 HttpClient 与 API 服务器通信，并使用 JSON 解析器库（例如 Google's gson）解析 JSON 请求/响应。
你可以找到很多关于如何使用 HttpClient 与远程服务器通信的教程，这里是其中之一（我不能保证它的质量）：
http://www.mysamplecode.com/2011/09/android-asynctask-httpclient-with.html
【讨论】：