Google API for Java 示例代码

Google API for Java 示例代码

Google API for Java是由Google开发的一个Java客户端类库，用于访问其提供的各种基于HTTP的服务。具有灵活、高效、强大等特点。这是访问基于REST或JSON-RPC的Google API推荐类库。

[代码] BigQuerySample.java

import com.google.api.client.googleapis.*;
import com.google.api.client.googleapis.auth.clientlogin.*;
import com.google.api.client.googleapis.json.*;
import com.google.api.client.http.*;
import java.io.*;

public class BigQuerySample {
  public static void main(String[] args) throws IOException {
    HttpTransport transport = GoogleTransport.create();
    transport.addParser(new JsonCParser());
    try {
      // authenticate with ClientLogin
      ClientLogin authenticator = new ClientLogin();
      authenticator.authTokenType = "ndev";
      authenticator.username = "...";
      authenticator.password = "...";
      authenticator.authenticate().setAuthorizationHeader(transport);
      // make query request
      HttpRequest request = transport.buildGetRequest();
      request.setUrl("https://www.googleapis.com/bigquery/v1/query");
      request.url.put(
          "q", "select count(*) from [bigquery/samples/shakespeare];");
      System.out.println(request.execute().parseAsString());
    } catch (HttpResponseException e) {
      System.err.println(e.response.parseAsString());
      throw e;
    }
  }
}

[代码] YouTubeSample.java

import com.google.api.client.googleapis.json.*;
import com.google.api.client.http.*;
import com.google.api.client.util.*;
import java.io.*;
import java.util.*;

public class YouTubeSample {

  public static class VideoFeed {
    @Key List<Video> items;
  }

  public static class Video {
    @Key String title;
    @Key String description;
    @Key Player player;
  }
 
  public static class Player {
    @Key("default") String defaultUrl;
  }

  public static class YouTubeUrl extends GenericUrl {
    @Key final String alt = "jsonc";
    @Key String author;
    @Key("max-results") Integer maxResults;
   
    YouTubeUrl(String url) { super(url); }
  }

  public static void main(String[] args) throws IOException {
    // setup up the HTTP transport
    HttpTransport transport = new HttpTransport();
    transport.defaultHeaders.put("GData-Version", "2");
    transport.addParser(new JsonCParser());
    // build the HTTP GET request and URL
    HttpRequest request = transport.buildGetRequest();
    YouTubeUrl url = new YouTubeUrl("https://gdata.youtube.com/feeds/api/videos");
    url.author = "searchstories";
    url.maxResults = 2;
    request.url = url;
    // execute the request and the parse video feed
    VideoFeed feed = request.execute().parseAs(VideoFeed.class);
    for (Video video : feed.items) {
      System.out.println();
      System.out.println("Video title: " + video.title);
      System.out.println("Description: " + video.description);
      System.out.println("Play URL: " + video.player.defaultUrl);
    }
  }
}

[代码] PicasaAndroidSample.java

public final class PicasaAndroidSample extends ListActivity {
...

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
...
    gotAccount(false);
  }

  @Override
  protected Dialog onCreateDialog(int id) {
    switch (id) {
      case DIALOG_ACCOUNTS:
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Select a Google account");
        final AccountManager manager = AccountManager.get(this);
        final Account[] accounts = manager.getAccountsByType("com.google");
        final int size = accounts.length;
        String[] names = new String[size];
        for (int i = 0; i < size; i++) {
          names[i] = accounts[i].name;
        }
        builder.setItems(names, new DialogInterface.OnClickListener() {
          public void onClick(DialogInterface dialog, int which) {
            gotAccount(manager, accounts[which]);
          }
        });
        return builder.create();
    }
    return null;
  }

  private void gotAccount(boolean tokenExpired) {
    SharedPreferences settings = getSharedPreferences(PREF, 0);
    String accountName = settings.getString("accountName", null);
    if (accountName != null) {
      AccountManager manager = AccountManager.get(this);
      Account[] accounts = manager.getAccountsByType("com.google");
      int size = accounts.length;
      for (int i = 0; i < size; i++) {
        Account account = accounts[i];
        if (accountName.equals(account.name)) {
          if (tokenExpired) {
            manager.invalidateAuthToken("com.google", this.authToken);
          }
          gotAccount(manager, account);
          return;
        }
      }
    }
    showDialog(DIALOG_ACCOUNTS);
  }

  private void gotAccount(final AccountManager manager, final Account account) {
    SharedPreferences settings = getSharedPreferences(PREF, 0);
    SharedPreferences.Editor editor = settings.edit();
    editor.putString("accountName", account.name);
    editor.commit();
    new Thread() {

      @Override
      public void run() {
        try {
          final Bundle bundle =
              manager.getAuthToken(account, AUTH_TOKEN_TYPE, true, null, null)
                  .getResult();
          runOnUiThread(new Runnable() {

            public void run() {
              try {
                if (bundle.containsKey(AccountManager.KEY_INTENT)) {
                  Intent intent =
                      bundle.getParcelable(AccountManager.KEY_INTENT);
                  int flags = intent.getFlags();
                  flags &= ~Intent.FLAG_ACTIVITY_NEW_TASK;
                  intent.setFlags(flags);
                  startActivityForResult(intent, REQUEST_AUTHENTICATE);
                } else if (bundle.containsKey(AccountManager.KEY_AUTHTOKEN)) {
                  authenticatedClientLogin(
                      bundle.getString(AccountManager.KEY_AUTHTOKEN));
                }
              } catch (Exception e) {
                handleException(e);
              }
            }
          });
        } catch (Exception e) {
          handleException(e);
        }
      }
    }.start();
  }

  @Override
  protected void onActivityResult(
      int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    switch (requestCode) {
      case REQUEST_AUTHENTICATE:
        if (resultCode == RESULT_OK) {
          gotAccount(false);
        } else {
          showDialog(DIALOG_ACCOUNTS);
        }
        break;
    }
  }

  private void authenticatedClientLogin(String authToken) {
    this.authToken = authToken;
    ((GoogleHeaders) transport.defaultHeaders).setGoogleLogin(authToken);
    authenticated();
  }
}