Yet Another Google App Engine Datastore ORM with a twirl! (We need your support, fork it, and try it)
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:: twirl :: Object Mapping ::
twirl aims to provide a lightweight Object mapping framework. Without adding complexity into the api.
Persisting POJO's, Maps and (soon Primitive types) directly into the Datastore.
##Sample
Usage sample can be found here: https://github.com/kerbymart/twirl-appengine-guestbook-java
##Setup
@Inject
ObjectStore store;
Friend friend = createComplexFriend();
Key key = store.put(friend);
Friend saved = store.get(Friend.class, friend.getId());
Iterator<Friend> all = store.find(Friend.class).greaterThanOrEqual("name", "Joe").now();
Friend one = store.findOne(Friend.class).greaterThanOrEqual("name", "Joe").now();Note that you can also use static import for store:
import static com.dotweblabs.twirl.ObjectStoreService.store;
store().put(friend);##Updating
####Save
Passing an object to the put(..) method will do the job.
Friend joe = new Friend("Joe", 27);
store.put(joe);
joe.age = 28;
store.put(joe);####Update
store.update(Friend.class).equals("name", "Joe").increment("age",1).now();
store.update(Friend.class).equals("name", "Joe").set("address", new Address(...)).now();
store.update(Friend.class).equals("name", "Joe").with(new Friend(..)).now();####Insert
store.put(new Friend(..));
store.put(new Friend(..), new Friend(..));####Remove
store.delete(key);
store.delete(friend.getId());##Object Mapping
@Entity(name="CloseFriends") // Optional name
public class Friend {
@Id
private long id; // Can be long, Long or String only
@Parent
private Circle circle;
@Child
private Box box;
@Embedded
private Map map;
private List<String> notes;
}##Querying
###Find & FindOne
Iterator<Friend> all = store.find(Friend.class).greaterThanOrEqual("name", "Joe").now();
Friend one = store.findOne(Friend.class).greaterThanOrEqual("name", "Joe").now();####Projection and Field selection
store.find(Friend.class).projection("firstName", "address").greaterThanOrEqual("name", "Joe").now();####Sorting
store.find(Friend.class).sortAscending("firstName").now();
store.find(Friend.class).sortDescending("lastName").now();####Skip and Limit
store.find(Friend.class).skip(20).now();
store.find(Friend.class).limit(10).now();####Cursors
String cursor = getRequestFromWebQuery();
// Should be empty String
// or valid cursor String only
Cursor startCursor = new Cursor(cursor);
ListResult<Post> posts = store.find(Post.class)
.limit(10)
.withCursor(startCursor)
.sortAscending("date")
.asList();
Cursor nextCursor = posts.getCursor();
return nextCursor.getWebSafeString();; ##Features
####Easy for JSON storage
// Note: Working but needs more work:
String jsonString = "{\"content\" : {\"Sample post\"}";
Map deserialized = deserialize(jsonString);
deserialized.put("__kind__", "Post");
store.put(deserialized);Or using a POJO :
public class JSONEntity {
@Kind
private String kind;
@Id
private String id;
@Flat
private Map<String,Object> fields;
}
JSONEntity entity = new JSONEntity();
entity.setKind("Post");
entity.setId("msgid:456");
entity.getFields().put("content", "Sample post");
entity.getFields().put("uid", 123);
store.put(entity);####Storing Primitive and Basic Java types
Using the keyvalue-extenstion:
KeyValueStore<String,String> messages = new StringKeyValueStore("Messages");
messages.put("uid:123:msgid:456", "Ahoy! We are saving primitives.");
String message = messages.get("uid:123:msgid:456");See: https://github.com/dotweblabs/twirl-keyvalue-extension
0.0.1
twirl uses a number of open source projects to work properly:
- [GAE SDK] - SDK for the AppEngine platform (GAE, AppScale or CapeDwarf)
- boon
mvn clean install
or add this to your POM:
<repositories>
<repository>
<id>dropbox.repo</id>
<url>http://maven.weblabs.ph/mvn-repostory</url>
</repository>
</repositories>
From JFrog (not updated ATM):
<repositories>
<!-- Snapshot repository -->
<repository>
<id>oss-jfrog-artifactory-snapshots</id>
<name>oss-jfrog-artifactory-snapshots</name>
<url>http://oss.jfrog.org/artifactory/oss-snapshot-local</url>
</repository>
</repositories>
<dependency>
<groupId>com.dotweblabs</groupId>
<artifactId>twirl</artifactId>
<version>0-SNAPSHOT</version>
</dependency>
- Anyone is welcome to contribute, implement feature or fix bugs.
Apache License, Version 2.0