Passing MongoDB ObjectId in Play Framework URL

Question

Hi I'm learning Play Framework 2 with Java and have a problem. I use MongoDB, and have a simple class User with ObjectId as unique id.

public class User {


    @JsonProperty
    public ObjectId id;

..

in my view I want to add a button to delete current user, something like this :

 @form(routes.Application.deleteUser(user.id)) {
       <input type="submit" value="Delete">
 }

and in my routes file :

POST    /users/:id/delete               controllers.Application.deleteUser(id: org.bson.types.ObjectId)

But now I got an error :

"No URL path binder found for type org.bson.types.ObjectId. Try to implement an implicit PathBindable for this type"

I tried a lot of things, for example I tried to pass only the ObjectId value as a String, but nothing worked for me. Can anyone please help me with this ?

There are binders in Scala, take a look, may be you could rewrite it in Java https://github.com/leon/play-salat/blob/master/src/main/scala/se/radley/plugin/salat/Binders.scala — lambdas, Dec 29 '12 at 07:31

lambdas · Accepted Answer · 2012-12-29T07:43:18.057

4

You could use play-salat which have neccessary binders, just add it as a dependency to your project/Build.scala and import it to your routes and templates:

import sbt._
import Keys._
import PlayProject._

object ApplicationBuild extends Build {

  val appDependencies = Seq(
    "se.radley" %% "play-plugins-salat" % "1.2-SNAPSHOT"
  )

  val main = PlayProject(appName, appVersion, appDependencies, mainLang = JAVA).settings(
    resolvers       += "OSS Snapshots" at "https://oss.sonatype.org/content/repositories/snapshots/",
    routesImport    += "se.radley.plugin.salat.Binders._",
    templatesImport += "org.bson.types.ObjectId"
  )
}

Also take a look to this example application.

edited Dec 29 '12 at 07:43

answered Dec 29 '12 at 07:38

lambdas

3,990
2
29
54

That would be great, but I need something in Java – Dawid Dec 29 '12 at 14:19
1

I know, but still think it would work for you. It is ok to use Scala libraries in Java application. – lambdas Dec 29 '12 at 15:43
I got another problem. There is an error : [NullPointerException: null] on line : Call("POST", "/users/" + implicitly[PathBindable[ObjectId]].unbind("id", id) + "/delete") – Dawid Dec 30 '12 at 12:36
Are you sure you passing id in this line `@form(routes.Application.deleteUser(user.id)) {`? Could you check by displaying it? It looks like your `user` is null. – lambdas Dec 30 '12 at 15:07
Thats a strange thing. For example in mongo console : > db.users.find() { "_id" : ObjectId("50d76439ba472c9cee2c5435"), "name" : "Franek" } { "_id" : ObjectId("50e0a25c4fbea3f0450d3690"), "name" : "Ziomek" } But when I want to display it in application : @for(user <- users) {
@(user.id)
@(user.name)

Dawid

Dec 30 '12 at 20:30

Ok I found what was wrong there. I just didnt add '("_id")' to the id field in User class. Thanks for your help! – Dawid Dec 30 '12 at 21:04

score 0 · Answer 2 · answered Dec 30 '12 at 04:26

Might you be looking for Morphia, MongoDB ORM for Java, afterall? For Morphia a good kick-start might be this tutorial in Slideshare.

Btw, i find for _id username String better contra Mongo's ObjectId.

Small example:

//Routes
GET     /add/:username     controllers.Application.createTestPerson(username)
GET    /delete/:username   controllers.Application.delete(username)

//Controller
public class Application extends Controller {
  ...
  public static Result createTestPerson(String username){
      //DB connection and Morphia Datastore
      DBConn conn = new DBConn("test");
      Datastore ds = conn.getDatastore();
      //Person document for saving
      Person person = new Person(username);
      person.setName("John", "Doe");
      //save person to Mongo
      ds.save(person);  
      return ok("user \""+username+"\" saved");
  }

  public static Result delete(String username){
      //DB connection and Morphia Datastore
      DBConn conn = new DBConn("test");
      Datastore ds = conn.getDatastore();
      ds.delete(Person.class,username);
      return ok("user \""+username+"\" deleted");
  }
}

//models Person.java
import com.google.code.morphia.annotations.*;
import org.bson.types.ObjectId;

@Entity("persons")
public class Person {

    @Id
    String userName;
    Name name;

    public Person(String u){ userName = u; }

    public void setName(String first, String last){
        name = new Name(first, last);
    }
}
@Embedded
class Name {
    String first, last;

    public Name(){ }
    public Name(String first, String last) {
        this.first = first;
        this.last = last;
    }
}


//models DBConn.java
import com.google.code.morphia.Datastore;
import com.google.code.morphia.Morphia;
import com.mongodb.Mongo;
import java.net.UnknownHostException;

public class DBConn implements AutoCloseable{
    Morphia morphia;
    Mongo mongo;
    Datastore ds;

    public DBConn(){
        new DBConn("test");
    }
    public DBConn(String collection){
        morphia = new Morphia();
        try {
            mongo = new Mongo();
        } catch (UnknownHostException ex) {
            System.out.println("[Error] MongoDB Error");
        }
        ds = morphia.createDatastore(mongo, collection);
        System.out.println("DB conn success ["+ ds.getDB().getName() + "]");
    }
    public Datastore getDatastore(){
        return ds;
    }
    public void close() throws Exception {
        mongo.close();
    }
}

So with

localhost:9000/delete/what-ever-here

localhost:9000/createTestPerson/what-ever-here

You should be able to manage Mongo Collection and see results in Mongo console:

> db.persons.find()
{ "_id" : "johndoe", "className" : "models.Person", "name" : { "first" : "John",
 "last" : "Doe" } }
>

I'm trying to work with Jongo and really would like to use ObjectId — Dawid, Dec 30 '12 at 12:37

score 0 · Answer 3 · answered Jul 08 '15 at 13:51

For Play 2.3.x with Java, on your build.sbt

import play.PlayImport.PlayKeys._

name := "test"

version := "1.0-SNAPSHOT"

lazy val root = (project in file(".")).enablePlugins(PlayJava)

scalaVersion := "2.11.6"

libraryDependencies ++= Seq(
  javaJdbc,
  cache,
  javaWs,
  filters,
  "org.mongodb" % "mongo-java-driver" % "3.0.1",
  "se.radley" %% "play-plugins-salat" % "1.5.0"
)

val main = Project("test", file(".")).enablePlugins(play.PlayJava).settings(
    routesImport += "se.radley.plugin.salat.Binders._"
)

and on your routes, you can use it by below way

controllers.Application.index(id: ObjectId)

Passing MongoDB ObjectId in Play Framework URL

3 Answers3