Play! framework for neo4j database

Features

• embedded database (Only, no REST API for now)
• create your graph by annotation, module do mapping for you
• for each of your model, plugin generate an unique id (key)
• you can declare an index by annotation
• define relationships with annotation @RelatedTo
• define relationships class with properties with annotation @RelatedToVia

Installation

add this to your application.conf

## NEO4J ----
module.neo4j=lib/
neo4j.path=db
%test.neo4j.path=dbTest

Place play-neo4j.jar in your "lib" directory

look in sample app to know wich libs you must import

Usage

Simple model

app/models/User.java

@Neo4jEntity
public class User extends Neo4jModel {
    public String login;
}

app/controllers/Application.java

User johndoe = new User();
johndoe.login = "johndoe";
try {
    johndoe.save();
} catch (Neo4jException e) {
    e.printStackTrace();
}

Graph

Will create this graph

then when adding a second user

Simple relationship (working but in progress)

app/models/User.java

@Neo4jEntity
public class User extends Neo4jModel {
    public String login;

    @RelatedTo(type = "KNOWS")
    public Set<User> friends;
}

app/controllers/Application.java

User johndoe = new User();
johndoe.login = "johndoe";
try {
    johndoe.save();
} catch (Neo4jException e) {
    e.printStackTrace();
}

User foobar = new User();
foobar.login = "foobar";
try {
    foobar.save();
} catch (Neo4jException e) {
    e.printStackTrace();
}
foobar.friends.add(johndoe);

Graph

Will create this graph

Relationship with attributes

app/models/User.java

@Neo4jEntity
public class User extends Neo4jModel {
    public String login;

    @RelatedTo(type = "KNOWS")
    public Set<User> friends;

    @RelatedToVia
    public Iterator<Bookmark> bookmarks;
}

app/models/Bookmark.java

 @Neo4jEdge(type = "BOOKMARKED")
 public class Bookmark extends Neo4jRelationship {
     @StartNode
     public User user;

     @EndNode
     public Post post;

     public int stars;
 }

app/models/Post.java

@Neo4jEntity
public class Post extends Neo4jModel {
    public String title;
    public String content;
}

app/controllers/Application.java

User johndoe = new User();
johndoe.login = "johndoe";
johndoe.save();

User foobar = new User();
foobar.login = "foobar";
foobar.save();
foobar.friends.add(johndoe);

Post myPost = new Post();
myPost.title = "nice !";
myPost.content = "blabla blabla bla";
myPost.save();

Bookmark bookmark = new Bookmark();
bookmark.post = myPost;
bookmark.user = foobar;
bookmark.stars = 5;
bookmark.save();

Graph

Will create this graph

See Junit Test in sample application for more !

TODO

• import / export from an YML format
• Adding more documentation