GAE Java - Day4 About CloudStorage and CloudSQL

1. GAE Developer - Day4
Simon @ MiCloud
2014Q1

2. Last Class
● Memcache basic
● Task Queue concept
● Push Queue
● Pull Queue

3. ● Create a Bucket
● Create a CloudSQL
Before Today

4. Create a Bucket
$ gcloud auth login
$ gcloud config set project [my-project-id]
$ gsutil mb gs://[my-bucket]
$ gsutil ls gs://[my-bucket]

5. Sample Database
http://www.mysqltutorial.org/mysql-sample-database.aspx

6. Create a CloudSQL
$ gcloud sql -h
$ gcloud sql instances create [inst-name]
$ gcloud sql instances list
$ gcloud sql instances import instance-name --uri
gs://your-bucket/sql-dump-file.gz
$ gcloud sql instances patch --assign-ip [inst-name]
$ gcloud sql instances get [inst-name]

7. Create a CloudSQL
$ gcloud sql instances set-root-password test-sql
-p [password]
$ gcloud sql instances patch test-sql
--authorized-networks=[your-ip-address]

8. Connect Cloud SQL - MySQL Workbench
http://www.mysql.com/products/workbench/

9. Today
● Use CloudStorage - BlobStore
● Connect CloudSQL

10. Using Cloud Storage

11. Use CloudStorage - BlobStore

12. Create Upload Url
BlobstoreService blobstoreService =
BlobstoreServiceFactory.getBlobstoreService();
UploadOptions uploadOptions =
UploadOptions.Builder.withGoogleStorageBucketName(
"BUCKET-NAME"); //Name without “gs://”
String uploadUrl = blobstoreService.createUploadUrl(
"/callback-url", uploadOptions);
resp.getWriter().println("<form action=" + uploadUrl
+ " method="post" enctype="multipart/form-data">");
resp.getWriter().println("<input type="file" name="field-name"");

13. public void doPost(HttpServletRequest req,
HttpServletResponse resp) throws IOException {
BlobstoreService blobstoreService =
BlobstoreServiceFactory.getBlobstoreService();
Map<String, List<FileInfo>> blobs = blobstoreService.getFileInfos(req);
List<FileInfo> keys = blobs.get("field-name"); //input file name on
form
if (keys != null && keys.size() > 0) {
FileInfo fileKey = keys.get(0);
String objectUploaded = fileKey.getGsObjectName();
…. (Save the objectUploaded mapping to datastore or database)
Create Callback Handler

14. Serving Data
public void doGet(HttpServletRequest req, HttpServletResponse resp){
BlobstoreService blobstoreService =
BlobstoreServiceFactory.getBlobstoreService();
BlobKey blobKey =
blobstoreService.createGsBlobKey("/gs/<bucket>/<object>");
try {
blobstoreService.serve(blobKey, resp);
} catch (IOException e){
e.printStackTrace();
}
….

15. Other Storage API
● Image API
● Cloud Storage Client Library

16. Connect Cloud SQL

17. Before Connect
● CloudSQL instance ready
● Authorized
○ root password
○ instance ip address
○ access ip address

18. Configure Connectors
● Hostname is Cloud SQL instance IP address
● Connection URL includes instance IP and
database name
● Java connection is:
jdbc:mysql://<instance-ip>:3306/

19. Local Test Configure
appengine-web.xml
<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
<application>mitac-cp300</application>
<version>eord</version>
….
<use-google-connector-j>true</use-google-connector-j>
….
</appengine-web-app>

20. Connect from App Engine
● JDBC
● Java Persistence API (JPA)
● Java Data Objects (JDO)
● Other JPAs custom additions: Hibernate, EclipseLink
jdbc:google:mysql://...
(instead of jdbc:mysql://...)

21. Detect running environment
Connection conn = null;
if (SystemProperty.environment.value() ==
SystemProperty.Environment.Value.Production) {
// app is running in production
Class.forName("com.mysql.jdbc.GoogleDriver");
String url= "jdbc:google:mysql://instance-name/";
conn = DriverManager.getConnection(url);
...
} else {
// app is running on localhost
Class.forName("com.mysql.jdbc.Driver");
String url= "jdbc:mysql://db-ip-address/";
conn = DriverManager.getConnection(url);
...
}
conn.~

22. DriverManager.registerDriver(new AppEngineDriver());
conn = DriverManager.getConnection(connUrl);
String sql = "SELECT count(*) as total FROM " + tableName + "";
PreparedStatement stmt = conn.prepareStatement(sql);
ResultSet results = stmt.executeQuery();
while (results.next()) {
int total = results.getInt("total");
…
}
Query Example - Standard JDBC

23. Other Frameworks
Popular frameworks for programming MySQL
● Hibernate (Java)
● JOOQ (Java)
● JPA ( Java )
● Django (Python)