# Problem with Java.Object

**URL:** <https://forums.fusetools.com/t/problem-with-java-object/6926>\
**Category:** General\
**Created:** [February 20, 2018, 8:14am UTC](https://forums.fusetools.com/t/problem-with-java-object/6926 "2018-02-20T08:14:21Z")\
**Posts on this page:** 10\
**Page:** 1

<div class="post-metadata">

**Author:** ![Uwadia\_Emovon](https://avatars.discourse-cdn.com/v4/letter/u/cdc98d/32.png) [@Uwadia\_Emovon](https://forums.fusetools.com/u/Uwadia_Emovon)\
**Post date:** [February 20, 2018, 8:14am UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/1 "2018-02-20T08:14:21Z")

</div>

Hello,  
I am trying to integrate an Android SMS Catcher Library into my Fuse App using Uno. I keep getting the error below:

```auto
Compiling syntax tree
SmsCatcher\SmsCatcher.uno(19.10): E3111: 'Java' does not contain type or namespace 'Object'. Could you be missing a package reference?
D:\PROJECTS\MOBILE\FUSE\HikerPlay\SmsCatcher\SmsCatcher.uno(19,11): Error E3111: 'Java' does not contain type or namespace 'Object'. Could you be missing a package reference?SmsCatcher\SmsCatcher.uno(19.10): E3111: 'Java' does not contain type or namespace 'Object'. Could you be missing a package reference?
D:\PROJECTS\MOBILE\FUSE\HikerPlay\SmsCatcher\SmsCatcher.uno(19,11): Error E3111: 'Java' does not contain type or namespace 'Object'. Could you be missing a package reference?0.48 s

```

from this line

```auto
Java.Object _smsCatcher;

```

If I change that line to

```auto
object _smsCatcher;

```

then the lines below

```auto
        this.AddMember(new NativeFunction("Start", (NativeCallback)Start));
        this.AddMember(new NativeFunction("Stop", (NativeCallback)Stop));

```

gives the following error

```auto
Compiling syntax tree
SmsCatcher\SmsCatcher.uno(36.68): E2029: '<method_group>' has no defined cast to type Fuse.Scripting.NativeCallback
D:\PROJECTS\MOBILE\FUSE\HikerPlay\SmsCatcher\SmsCatcher.uno(36,69): Error E2029: '<method_group>' has no defined cast to type Fuse.Scripting.NativeCallbackSmsCatcher\SmsCatcher.uno(37.67): E2029: '<method_group>' has no defined cast to type Fuse.Scripting.NativeCallback
D:\PROJECTS\MOBILE\FUSE\HikerPlay\SmsCatcher\SmsCatcher.uno(37,68): Error E2029: '<method_group>' has no defined cast to type Fuse.Scripting.NativeCallback0.98 s

```

Here is the full source code

```auto
using Uno;
using Fuse;
using Uno.UX;
using Android;
using Fuse.Platform;
using Fuse.Reactive;
using Fuse.Scripting;
using Uno.Threading;
using Uno.Permissions;
using Uno.Compiler.ExportTargetInterop;

[extern(Android) ForeignInclude(Language.Java, "android.content.Intent")]
[extern(Android) ForeignInclude(Language.Java, "android.util.Log")]
[extern(Android) ForeignInclude(Language.Java, "com.goldenseed.smscatcher.*")]
[extern(Android) ForeignInclude(Language.Java, "com.fuse.Activity")]
[UXGlobalModule]
public class SmsCatcher : NativeEventEmitterModule
{
    Java.Object _smsCatcher; // <====== PROBLEM LINE
    static readonly SmsCatcher _instance;
    static readonly string PLATFORM_NOT_SUPPORTED = "Non Android Platforms are not Supported";

    public SmsCatcher() : base(true, "SMSRECEIVED", "SMSERROR", "PermissionReceived", "PermissionDenied")
    {
        if defined(Android)
        {
            Permissions.Request(Permissions.Android.INTERNET).Then(OnPermissionsPermitted,OnPermissionsRejected);
            Permissions.Request(Permissions.Android.READ_SMS).Then(OnPermissionsPermitted,OnPermissionsRejected);
            Permissions.Request(Permissions.Android.RECEIVE_SMS).Then(OnPermissionsPermitted,OnPermissionsRejected);
        }

        if (_instance != null) return;

	_instance = this;
	Uno.UX.Resource.SetGlobalKey(_instance, "SmsCatcher");
        this.AddMember(new NativeFunction("Start", (NativeCallback)Start));// <====== PROBLEM LINE
        this.AddMember(new NativeFunction("Stop", (NativeCallback)Stop));// <====== PROBLEM LINE
    }

    extern(Android) void Start(Fuse.Scripting.Context c, object[] args)
    {
		if (this._smsCatcher == null) {
            this.Init();
        }

        if (args.Length > 0){
            if (args[0] != null){
                var phoneNumberFilter = (string)args[0];
                this.SetPhoneNumberFilter(phoneNumberFilter);
            }

            if (args.Length > 1){
                if (args[1] != null){
                    var regexFilter = (string)args[1];
                    this.SetRegexFilter(regexFilter);
                }
            }
        }

        this.StartSmsCatcher();
    }
    extern(!Android) void Start(Fuse.Scripting.Context c, object[] args)
    {
        debug_log PLATFORM_NOT_SUPPORTED;
        this.Emit("SMSERROR", PLATFORM_NOT_SUPPORTED);
    }

    extern(Android) void Stop()
    {
        if (this._smsCatcher != null) {
            this.StopSmsCatcher();
        }
    }
    extern(!Android) void Stop()
    {
        debug_log PLATFORM_NOT_SUPPORTED;
        this.Emit("SMSERROR", PLATFORM_NOT_SUPPORTED);
    }

    public void onSmsMessage(string smsMessage)
    {
        this.Emit("SMSRECEIVED", smsMessage);
    }

    extern(Android) void OnPermissionsPermitted(PlatformPermission p)
    {
        this.Emit("PermissionReceived", "Permissions allowed" + p);
    }

    extern(Android) void OnPermissionsRejected(Exception e)
    {
        this.Emit("PermissionDenied", "PermissionDenied "+ e);
    }

    [Foreign(Language.Java)]
    extern(Android) void StartSmsCatcher()
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.onStart();
    @}

    [Foreign(Language.Java)]
    extern(Android) void StopSmsCatcher()
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.onStop();

    @}

    [Foreign(Language.Java)]
    extern(Android) void SetRegexFilter(string regexFiler)
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.setFilter(regexFiler);
    @}

    [Foreign(Language.Java)]
    extern(Android) void SetPhoneNumberFilter(string phoneNumber)
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.setPhoneNumberFilter(phoneNumber);
    @}

    [Foreign(Language.Java)]
    extern(Android) void Init()
    @{
        AndroidSmsCatcher smsCatcher = new AndroidSmsCatcher(Activity.getRootActivity(), new OnSmsCatchListener<String>() {
            @Override
            public void onSmsCatch(String message) {
                 @{SmsCatcher:Of(_this).onSmsMessage(string):Call(message)};
            }
        });

        @{SmsCatcher:Of(_this)._smsCatcher:Set(smsCatcher)};
    @}
}

```

The java source files are bundled with the project  
I have tried `uno clean` but no luck  
What am I doing wrong? I have been on this for 2 days.  
I am new to Fuse but experienced in C#;

---

<div class="post-metadata">

**Author:** ![Uldis](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/uldis/32/657_2.png) [@Uldis](https://forums.fusetools.com/u/Uldis)\
**Post date:** [February 20, 2018, 8:44am UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/2 "2018-02-20T08:44:15Z")

</div>

Your `AddMember()` lines are fine. And looking for `Java.Object` while in Uno doesn’t seem right, you still need to work with Uno-types.

The problem is that the callback functions do not match the signature of a `NativeCallback`.

It’s the actual callback methods that need to return an `object`, and accept the right arguments. Fixed your code so that it compiles for me without any errors (but didn’t test if it actually does anything):

```auto
using Uno;
using Fuse;
using Uno.UX;
using Android;
using Fuse.Platform;
using Fuse.Reactive;
using Fuse.Scripting;
using Uno.Threading;
using Uno.Permissions;
using Uno.Compiler.ExportTargetInterop;

[extern(Android) ForeignInclude(Language.Java, "android.content.Intent")]
[extern(Android) ForeignInclude(Language.Java, "android.util.Log")]
[extern(Android) ForeignInclude(Language.Java, "com.goldenseed.smscatcher.*")]
[extern(Android) ForeignInclude(Language.Java, "com.fuse.Activity")]
[UXGlobalModule]
public class SmsCatcher : NativeEventEmitterModule
{
    object _smsCatcher; // <====== PROBLEM LINE
    static readonly SmsCatcher _instance;
    static readonly string PLATFORM_NOT_SUPPORTED = "Non Android Platforms are not Supported";

    public SmsCatcher() : base(true, "SMSRECEIVED", "SMSERROR", "PermissionReceived", "PermissionDenied")
    {
        if defined(Android)
        {
            Permissions.Request(Permissions.Android.INTERNET).Then(OnPermissionsPermitted,OnPermissionsRejected);
            Permissions.Request(Permissions.Android.READ_SMS).Then(OnPermissionsPermitted,OnPermissionsRejected);
            Permissions.Request(Permissions.Android.RECEIVE_SMS).Then(OnPermissionsPermitted,OnPermissionsRejected);
        }

        if (_instance != null) return;

    _instance = this;
    Uno.UX.Resource.SetGlobalKey(_instance, "SmsCatcher");
        this.AddMember(new NativeFunction("Start", (NativeCallback)Start));// <====== PROBLEM LINE
        this.AddMember(new NativeFunction("Stop", (NativeCallback)Stop));// <====== PROBLEM LINE
    }

    extern(Android) object Start(Fuse.Scripting.Context c, object[] args)
    {
        if (this._smsCatcher == null) {
            this.Init();
        }

        if (args.Length > 0){
            if (args[0] != null){
                var phoneNumberFilter = (string)args[0];
                this.SetPhoneNumberFilter(phoneNumberFilter);
            }

            if (args.Length > 1){
                if (args[1] != null){
                    var regexFilter = (string)args[1];
                    this.SetRegexFilter(regexFilter);
                }
            }
        }

        this.StartSmsCatcher();

        return null;
    }
    extern(!Android) object Start(Fuse.Scripting.Context c, object[] args)
    {
        debug_log PLATFORM_NOT_SUPPORTED;
        this.Emit("SMSERROR", PLATFORM_NOT_SUPPORTED);
        return null;
    }

    extern(Android) object Stop(Fuse.Scripting.Context c, object[] args)
    {
        if (this._smsCatcher != null) {
            this.StopSmsCatcher();
        }
        return null;
    }
    extern(!Android) object Stop(Fuse.Scripting.Context c, object[] args)
    {
        debug_log PLATFORM_NOT_SUPPORTED;
        this.Emit("SMSERROR", PLATFORM_NOT_SUPPORTED);
        return null;
    }

    public void onSmsMessage(string smsMessage)
    {
        this.Emit("SMSRECEIVED", smsMessage);
    }

    extern(Android) void OnPermissionsPermitted(PlatformPermission p)
    {
        this.Emit("PermissionReceived", "Permissions allowed" + p);
    }

    extern(Android) void OnPermissionsRejected(Exception e)
    {
        this.Emit("PermissionDenied", "PermissionDenied "+ e);
    }

    [Foreign(Language.Java)]
    extern(Android) void StartSmsCatcher()
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.onStart();
    @}

    [Foreign(Language.Java)]
    extern(Android) void StopSmsCatcher()
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.onStop();

    @}

    [Foreign(Language.Java)]
    extern(Android) void SetRegexFilter(string regexFiler)
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.setFilter(regexFiler);
    @}

    [Foreign(Language.Java)]
    extern(Android) void SetPhoneNumberFilter(string phoneNumber)
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.setPhoneNumberFilter(phoneNumber);
    @}

    [Foreign(Language.Java)]
    extern(Android) void Init()
    @{
        AndroidSmsCatcher smsCatcher = new AndroidSmsCatcher(Activity.getRootActivity(), new OnSmsCatchListener<String>() {
            @Override
            public void onSmsCatch(String message) {
                 @{SmsCatcher:Of(_this).onSmsMessage(string):Call(message)};
            }
        });

        @{SmsCatcher:Of(_this)._smsCatcher:Set(smsCatcher)};
    @}
}

```

---

<div class="post-metadata">

**Author:** ![Uwadia\_Emovon](https://avatars.discourse-cdn.com/v4/letter/u/cdc98d/32.png) [@Uwadia\_Emovon](https://forums.fusetools.com/u/Uwadia_Emovon)\
**Post date:** [February 20, 2018, 8:54am UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/3 "2018-02-20T08:54:30Z")

</div>

Thanks for the Fast Response. Does your fix take care of the `Java.Object` problem?  
I will Test your fix and get back to you.  
Thanks

---

<div class="post-metadata">

**Author:** ![Uldis](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/uldis/32/657_2.png) [@Uldis](https://forums.fusetools.com/u/Uldis)\
**Post date:** [February 20, 2018, 9:09am UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/4 "2018-02-20T09:09:01Z")

</div>

Yeah, it does fix the `Java.Object` problem, since there is no reference to `Java.Object` any more.

As I said above, I fixed the code so that it compiles without any errors, but I didn’t test if it does what it’s supposed to do. That’s on you.

---

<div class="post-metadata">

**Author:** ![Uwadia\_Emovon](https://avatars.discourse-cdn.com/v4/letter/u/cdc98d/32.png) [@Uwadia\_Emovon](https://forums.fusetools.com/u/Uwadia_Emovon)\
**Post date:** [February 20, 2018, 9:59am UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/5 "2018-02-20T09:59:15Z")

</div>

My problem with `AddMember()` is fixed now, but I still have issues with this code

```auto
Java.Object _smsCatcher;

```

`_smsCatcher` is a variable in Uno that I want store a native Java Object in so I can use later when I need to call a method on it but I keep getting compile error

```auto
Compiling syntax tree
SmsCatcher\SmsCatcher.uno(19.10): E3111: 'Java' does not contain type or namespace 'Object'. Could you be missing a package reference?
D:\PROJECTS\MOBILE\FUSE\HikerPlay\SmsCatcher\SmsCatcher.uno(19,11): Error E3111: 'Java' does not contain type or namespace 'Object'. Could you be missing a package reference?SmsCatcher\SmsCatcher.uno(19.10): E3111: 'Java' does not contain type or namespace 'Object'. Could you be missing a package reference?
D:\PROJECTS\MOBILE\FUSE\HikerPlay\SmsCatcher\SmsCatcher.uno(19,11): Error E3111: 'Java' does not contain type or namespace 'Object'. Could you be missing a package reference?0.41 s

```

# From Fuse Docs,

[So what happens when we want to return a Java or Objective-C object from a foreign method? The answer is that we get an opaque object representing the foreign object.

An Objective-C object (id) is an `ObjC.Object` and a Java object (Object) is a ```Java.Object`` in Uno."]

I am on Fuse 1.6.1, it appears Java.Object does not exist in my setup, but I have compiled and previewed sample projects that make use of ```Java.Object`` successfully.

In what Uno namespace do I find `ObjC.Object` and ```Java.Object``?

How do I store a return value from a Java Foreign method in Uno?

---

<div class="post-metadata">

**Author:** ![Uldis](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/uldis/32/657_2.png) [@Uldis](https://forums.fusetools.com/u/Uldis)\
**Post date:** [February 20, 2018, 10:13am UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/6 "2018-02-20T10:13:15Z")

</div>

Oh, I see your point now.

`Java.Object` is only available to code running on Android target, while `ObjC.Object` is when you’re on iOS. You can take a look at [one of these libraries](https://github.com/fuse-compound/) since many of them use both.

For example, take a look [at this line](https://github.com/fuse-compound/Fuse.StreamingPlayer/blob/ffdbaa16fea6312db543fcf4286afb077d998e80/src/Android/StreamingPlayer.uno#L29). Note the use of `extern(Android)` in the method signature - meaning, this code gets compiled for Android.

---

<div class="post-metadata">

**Author:** ![Uwadia\_Emovon](https://avatars.discourse-cdn.com/v4/letter/u/cdc98d/32.png) [@Uwadia\_Emovon](https://forums.fusetools.com/u/Uwadia_Emovon)\
**Post date:** [February 20, 2018, 11:28am UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/7 "2018-02-20T11:28:14Z")

</div>

Your last reply was the MAGIC WAND I needed to move forward. What I eventually did was to create two classes, one for Android and another one for other platforms as shown below:

```auto
[UXGlobalModule]
extern(!Android) public class SmsCatcher : NativeEventEmitterModule
{
    static readonly string PLATFORM_NOT_SUPPORTED = "Non Android Platforms are not Supported";

    public SmsCatcher() : base(true, "SMSRECEIVED", "SMSERROR", "PermissionReceived", "PermissionDenied")
    {
        this.AddMember(new NativeFunction("Start", (NativeCallback)Start));
        this.AddMember(new NativeFunction("Stop", (NativeCallback)Stop));
    }

    extern(!Android) object Start(Fuse.Scripting.Context c, object[] args)
    {
        debug_log PLATFORM_NOT_SUPPORTED;
        this.Emit("SMSERROR", PLATFORM_NOT_SUPPORTED);
        return null;
    }

    extern(!Android) object Stop(Fuse.Scripting.Context c, object[] args)
    {
        debug_log PLATFORM_NOT_SUPPORTED;
        this.Emit("SMSERROR", PLATFORM_NOT_SUPPORTED);
        return null;
    }
}

```

AND

```auto
[extern(Android) ForeignInclude(Language.Java, "android.content.Intent")]
[extern(Android) ForeignInclude(Language.Java, "android.util.Log")]
[extern(Android) ForeignInclude(Language.Java, "com.goldenseed.smscatcher.*")]
[extern(Android) ForeignInclude(Language.Java, "com.fuse.Activity")]
[UXGlobalModule]
extern(Android) public class SmsCatcher : NativeEventEmitterModule
{
    Java.Object _smsCatcher;
    static readonly SmsCatcher _instance;

    public SmsCatcher() : base(true, "SMSRECEIVED", "SMSERROR", "PermissionReceived", "PermissionDenied")
    {
        if defined(Android)
        {
            Permissions.Request(Permissions.Android.INTERNET).Then(OnPermissionsPermitted,OnPermissionsRejected);
            Permissions.Request(Permissions.Android.READ_SMS).Then(OnPermissionsPermitted,OnPermissionsRejected);
            Permissions.Request(Permissions.Android.RECEIVE_SMS).Then(OnPermissionsPermitted,OnPermissionsRejected);
        }

        if (_instance != null) return;

	_instance = this;
	Uno.UX.Resource.SetGlobalKey(_instance, "SmsCatcher");
        this.AddMember(new NativeFunction("Start", (NativeCallback)Start));
        this.AddMember(new NativeFunction("Stop", (NativeCallback)Stop));
    }

    extern(Android) object Start(Fuse.Scripting.Context c, object[] args)
    {
        if (this._smsCatcher == null) {
            this.Init();
        }

        if (args.Length > 0){
            if (args[0] != null){
                var phoneNumberFilter = (string)args[0];
                this.SetPhoneNumberFilter(phoneNumberFilter);
            }

            if (args.Length > 1){
                if (args[1] != null){
                    var regexFilter = (string)args[1];
                    this.SetRegexFilter(regexFilter);
                }
            }
        }

        this.StartSmsCatcher();

        return null;
    }

    extern(Android) object Stop(Fuse.Scripting.Context c, object[] args)
    {
        if (this._smsCatcher != null) {
            this.StopSmsCatcher();
        }
        return null;
    }

    public void onSmsMessage(string smsMessage)
    {
        this.Emit("SMSRECEIVED", smsMessage);
    }

    extern(Android) void OnPermissionsPermitted(PlatformPermission p)
    {
        this.Emit("PermissionReceived", "Permissions allowed" + p);
    }

    extern(Android) void OnPermissionsRejected(Exception e)
    {
        this.Emit("PermissionDenied", "PermissionDenied "+ e);
    }

    [Foreign(Language.Java)]
    extern(Android) void StartSmsCatcher()
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.onStart();
    @}

    [Foreign(Language.Java)]
    extern(Android) void StopSmsCatcher()
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.onStop();

    @}

    [Foreign(Language.Java)]
    extern(Android) void SetRegexFilter(string regexFiler)
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.setFilter(regexFiler);
    @}

    [Foreign(Language.Java)]
    extern(Android) void SetPhoneNumberFilter(string phoneNumber)
    @{
        AndroidSmsCatcher smsCatcher = (AndroidSmsCatcher)@{SmsCatcher:Of(_this)._smsCatcher:Get()};
        smsCatcher.setPhoneNumberFilter(phoneNumber);
    @}

    [Foreign(Language.Java)]
    extern(Android) void Init()
    @{
        AndroidSmsCatcher smsCatcher = new AndroidSmsCatcher(Activity.getRootActivity(), new OnSmsCatchListener<String>() {
            @Override
            public void onSmsCatch(String message) {
                 @{SmsCatcher:Of(_this).onSmsMessage(string):Call(message)};
            }
        });

        @{SmsCatcher:Of(_this)._smsCatcher:Set(smsCatcher)};
    @}
}

```

Now my project compiles with no errors. I only need to test on a real android device

Thanks @Uldis for your patience;

I am amazed at the creativity that goes into creating a Mobile Platform like Fuse. Having done WPF and Silverlight from Microsoft, I feel like I am on familiar grounds and that this is WPF made perfect.

---

<div class="post-metadata">

**Author:** ![Uldis](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/uldis/32/657_2.png) [@Uldis](https://forums.fusetools.com/u/Uldis)\
**Post date:** [February 20, 2018, 1:08pm UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/8 "2018-02-20T13:08:48Z")

</div>

Wonderful! It’s great you got it working. The approach with native modules in Fuse is usually exactly that: writing 3 different implementations for the actual functionality targeting each platform (local preview, Android and iOS), and having a common base class that serves as a single entry-point.

Thanks for the kind words 🙂

---

<div class="post-metadata">

**Author:** ![Uwadia\_Emovon](https://avatars.discourse-cdn.com/v4/letter/u/cdc98d/32.png) [@Uwadia\_Emovon](https://forums.fusetools.com/u/Uwadia_Emovon)\
**Post date:** [February 20, 2018, 8:54pm UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/9 "2018-02-20T20:54:26Z")

</div>

@Uldis I tested it on my Android device and it worked. I will be sharing the full code with the community in the coming days.

I think the Docs should be updated to point out that `Java.Object` is only available to code running on Android target, while `ObjC.Object` is only available when you’re on iOS.

The take away for me is to always partition your Foreign code using `extern()` to target your platform of choice while providing dummy implementation for platforms you don’t intend to support

Thanks a lot.

---

<div class="post-metadata">

**Author:** ![aeq](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/aeq/32/129_2.png) [@aeq](https://forums.fusetools.com/u/aeq)\
**Post date:** [May 31, 2018, 5:21pm UTC](https://forums.fusetools.com/t/problem-with-java-object/6926/10 "2018-05-31T17:21:01Z")

</div>

I came across the same issue, the compiler kept throwing this error:  
`E3111: 'Java' does not contain type or namespace 'Object'. Could you be missing a package reference?`

Thanks guys!

I added:

`using Android;`

and made sure to use `extern(Android)` for functions that may include a Java object, even if the Uno function isn’t written with the Java language but includes a Java object (in my case type `Java.Object`) as input from a function call inside a function using Java.