/* Copyright (c) 2006 Google Inc.
*
* 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 sample.gbase.basic;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.StringTokenizer;
/**
* Add a new item to Google Base using the Google Base data API server.
*/
public class InsertExample {
/**
* URL of the authenticated customer feed.
*/
private static final String ITEMS_FEED = "http://base.google.com/base/feeds/items";
/**
* The data item we are going to insert, in XML/Atom format.
*/
private static final String DATA_ITEM =
"<?xml version='1.0'?>\n" +
"<entry xmlns='http://www.w3.org/2005/Atom'\n" +
" xmlns:g='http://base.google.com/ns/1.0'>\n" +
" <g:item_type type='text'>testrecipes</g:item_type>\n" +
" <title type='text'>Fabulous cheese cake</title>\n" +
" <content type='xhtml'>All that you need is lots of patience.</content>\n" +
"</entry>";
/**
* URL used for authenticating and obtaining an authentication token.
* More details about how it works:
* <code>http://code.google.com/apis/accounts/AuthForInstalledApps.html<code>
*/
private static final String AUTHENTICATION_URL = "https://www.google.com/accounts/ClientLogin";
/**
* Fill in your Google Account email here.
*/
private static final String EMAIL = "";
/**
* Fill in your Google Account password here.
*/
private static final String PASSWORD = "";
/**
* The main method constructs a <code>InsertExample</code> instance, obtains an
* authorization token and posts a new item to Google Base.
*/
public static void main(String[] args) throws MalformedURLException, IOException {
InsertExample insertExample = new InsertExample();
String token = insertExample.authenticate();
System.out.println("Obtained authorization token: " + token);
insertExample.postItem(token);
}
/**
* Inserts <code>DATA_ITEM</code> by making a POST request to
* <code>ITEMS_URL<code>.
* @param token authentication token obtained using <code>authenticate</code>
* @throws IOException if an I/O exception occurs while creating/writing/
* reading the request
*/
public void postItem(String token) throws IOException {
HttpURLConnection connection = (HttpURLConnection)(new URL(ITEMS_FEED)).openConnection();
connection.setDoInput(true);
connection.setDoOutput(true);
// Set the properties of the connection: the Http method, the content type
// of the POST request and the authorization header
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/atom+xml");
connection.setRequestProperty("Authorization", "GoogleLogin auth=" + token);
// Post the data item
OutputStream outputStream = connection.getOutputStream();
outputStream.write(DATA_ITEM.getBytes());
outputStream.close();
// Retrieve the output
int responseCode = connection.getResponseCode();
InputStream inputStream;
if (responseCode == HttpURLConnection.HTTP_CREATED) {
inputStream = connection.getInputStream();
} else {
inputStream = connection.getErrorStream();
}
// write the output to the console
System.out.println(toString(inputStream));
}
/**
* Retrieves the authentication token for the provided set of credentials.
* @return the authorization token that can be used to access authenticated
* Google Base data API feeds
*/
public String authenticate() {
// create the login request
String postOutput = null;
try {
URL url = new URL(AUTHENTICATION_URL);
postOutput = makeLoginRequest(url);
} catch (IOException e) {
System.out.println("Could not connect to authentication server: "
+ e.toString());
System.exit(1);
}
// Parse the result of the login request. If everything went fine, the
// response will look like
// HTTP/1.0 200 OK
// Server: GFE/1.3
// Content-Type: text/plain
// SID=DQAAAGgA...7Zg8CTN
// LSID=DQAAAGsA...lk8BBbG
// Auth=DQAAAGgA...dk3fA5N
// so all we need to do is look for "Auth" and get the token that comes after it
StringTokenizer tokenizer = new StringTokenizer(postOutput, "=\n ");
String token = null;
while (tokenizer.hasMoreElements()) {
if (tokenizer.nextToken().equals("Auth")) {
if (tokenizer.hasMoreElements()) {
token = tokenizer.nextToken();
}
break;
}
}
if (token == null) {
System.out.println("Authentication error. Response from server:\n" + postOutput);
System.exit(1);
}
return token;
}
/**
* Makes a HTTP POST request to the provided {@code url} given the provided
* {@code parameters}. It returns the output from the POST handler as a
* String object.
*
* @param url the URL to post the request
* @return the output from the handler
* @throws IOException if an I/O exception occurs while
* creating/writing/reading the request
*/
private String makeLoginRequest(URL url)
throws IOException {
// Create a login request. A login request is a POST request that looks like
// POST /accounts/ClientLogin HTTP/1.0
// Content-type: application/x-www-form-urlencoded
// Email=johndoe@gmail.com&Passwd=north23AZ&service=gbase&source=Insert Example
// Open connection
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
// Set properties of the connection
urlConnection.setRequestMethod("POST");
urlConnection.setDoInput(true);
urlConnection.setDoOutput(true);
urlConnection.setUseCaches(false);
urlConnection.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
// Form the POST parameters
StringBuilder content = new StringBuilder();
content.append("Email=").append(URLEncoder.encode(EMAIL, "UTF-8"));
content.append("&Passwd=").append(URLEncoder.encode(PASSWORD, "UTF-8"));
content.append("&source=").append(URLEncoder.encode("Google Base data API example", "UTF-8"));
content.append("&service=").append(URLEncoder.encode("gbase", "UTF-8"));
OutputStream outputStream = urlConnection.getOutputStream();
outputStream.write(content.toString().getBytes("UTF-8"));
outputStream.close();
// Retrieve the output
int responseCode = urlConnection.getResponseCode();
InputStream inputStream;
if (responseCode == HttpURLConnection.HTTP_OK) {
inputStream = urlConnection.getInputStream();
} else {
inputStream = urlConnection.getErrorStream();
}
return toString(inputStream);
}
/**
* Writes the content of the input stream to a <code>String<code>.
*/
private String toString(InputStream inputStream) throws IOException {
String string;
StringBuilder outputBuilder = new StringBuilder();
if (inputStream != null) {
BufferedReader reader =
new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
while (null != (string = reader.readLine())) {
outputBuilder.append(string).append('\n');
}
}
return outputBuilder.toString();
}
}