/
UrlShortener.java
78 lines (72 loc) · 3.15 KB
/
UrlShortener.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
/*
* Copyright 2016 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 com.example.appengine.appidentity;
import com.google.appengine.api.appidentity.AppIdentityService;
import com.google.appengine.api.appidentity.AppIdentityServiceFactory;
import com.google.common.io.CharStreams;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import org.json.JSONObject;
import org.json.JSONTokener;
@SuppressWarnings("serial")
class UrlShortener {
// [START asserting_identity_to_Google_APIs]
/**
* Returns a shortened URL by calling the Google URL Shortener API.
*
* <p>Note: Error handling elided for simplicity.
*/
public String createShortUrl(String longUrl) throws Exception {
ArrayList<String> scopes = new ArrayList<String>();
scopes.add("https://www.googleapis.com/auth/urlshortener");
final AppIdentityService appIdentity = AppIdentityServiceFactory.getAppIdentityService();
final AppIdentityService.GetAccessTokenResult accessToken = appIdentity.getAccessToken(scopes);
// The token asserts the identity reported by appIdentity.getServiceAccountName()
JSONObject request = new JSONObject();
request.put("longUrl", longUrl);
URL url = new URL("https://www.googleapis.com/urlshortener/v1/url?pp=1");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.addRequestProperty("Content-Type", "application/json");
connection.addRequestProperty("Authorization", "Bearer " + accessToken.getAccessToken());
OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream());
request.write(writer);
writer.close();
if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
// Note: Should check the content-encoding.
// Any JSON parser can be used; this one is used for illustrative purposes.
JSONTokener responseTokens = new JSONTokener(connection.getInputStream());
JSONObject response = new JSONObject(responseTokens);
return (String) response.get("id");
} else {
try (InputStream s = connection.getErrorStream();
InputStreamReader r = new InputStreamReader(s, StandardCharsets.UTF_8)) {
throw new RuntimeException(String.format(
"got error (%d) response %s from %s",
connection.getResponseCode(),
CharStreams.toString(r),
connection.toString()));
}
}
}
// [END asserting_identity_to_Google_APIs]
}