Re: [go-nuts] Re: x/mobile: Samples for reverse binding in gomobile
Hello Elias,
*First of all, Thank you very much for help. :)*
*After I remove the static from function it worked well. *
*Thanks*
On Thursday, September 12, 2019 at 4:31:05 PM UTC+5:30, Elias Naur wrote:
>
> On Thu Sep 12, 2019 at 2:35 AM Jay Sharma wrote:
> >
> > *Hello Elias,*
> >
> > *Following is my java file: *
> >
> >
> > package reversebinding;
> >
> > public class RBinding {
> > public static String getStringFromJava() {
> > return "Hello from java !!";
> > }
> > }
> >
> >
> >
>
> Your Java method is declared as "static"; static methods are exported as
> regular functions in reverse bindings. Remove "static" and you might have
> better luck calling it.
>
> >
> > *I tried the following in my go file : *
> >
> >
> >
> > import "Java/reversebinding/RBinding"
> >
> >
> > // creating object like this:
> >
> > javaObj := JavaAPI.New()
> > javaObj.GetStringFromJava()
> >
> > *But while building using the gomobile it is giving following error: *
> > JavaObj.GetStringFromJava undefined (type Java.Reversebinding_JavaAPI
> has
> > no field or method GetStringFromJava)
> > undefined: val
> >
> >
>
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Re: [go-nuts] Re: x/mobile: Samples for reverse binding in gomobile
*Hello Elias,*
*Following is my java file: *
package reversebinding;
public class RBinding {
public static String getStringFromJava() {
return "Hello from java !!";
}
}
*I tried the following in my go file : *
import "Java/reversebinding/RBinding"
// creating object like this:
javaObj := JavaAPI.New()
javaObj.GetStringFromJava()
*But while building using the gomobile it is giving following error: *
JavaObj.GetStringFromJava undefined (type Java.Reversebinding_JavaAPI has
no field or method GetStringFromJava)
undefined: val
*If I call using class name: it is working fine. but with object it is not
working.*
*Can you please provide your suggestion ? *
*Thanks.*
On Thursday, September 12, 2019 at 1:14:21 PM UTC+5:30, Jay Sharma wrote:
>
> Hello Elias,
>
> Following are the lines from proposals:
> Creating new Java instances
>
> To create a new instance of a Java class, use the New function defined in
> the class package. For example:
>
> import (
> "Java/java/lang/Object" "Java/java/lang"
> )
>
> func NewObject() lang.Object {
> return Object.New()
> }
>
> *How can I modify it for my class ? *
>
> I know, It is too much to ask. I got confused.
>
> *Thanks for your help.*
>
>
>
>
> On Wednesday, September 11, 2019 at 9:41:13 PM UTC+5:30, Elias Naur wrote:
>>
>> On Wed Sep 11, 2019 at 7:20 AM Jay Sharma wrote:
>> >
>> >
>> > *Now, I want to create object of this class in go and want to call
>> method
>> > using that object from go. *
>> >
>> > I was checking your proposal (https://github.com/golang/go/issues/16876)
>>
>> > but could not able to make it. :(
>>
>> The proposal suggests calling the generated New method on the object.
>> Did you try that? If so, what went wrong?
>>
>> -- elias
>>
>
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Re: [go-nuts] Re: x/mobile: Samples for reverse binding in gomobile
Hello Elias,
Following are the lines from proposals:
Creating new Java instances
To create a new instance of a Java class, use the New function defined in
the class package. For example:
import (
"Java/java/lang/Object" "Java/java/lang"
)
func NewObject() lang.Object {
return Object.New()
}
*How can I modify it for my class ? *
I know, It is too much to ask. I got confused.
*Thanks for your help.*
On Wednesday, September 11, 2019 at 9:41:13 PM UTC+5:30, Elias Naur wrote:
>
> On Wed Sep 11, 2019 at 7:20 AM Jay Sharma wrote:
> >
> >
> > *Now, I want to create object of this class in go and want to call
> method
> > using that object from go. *
> >
> > I was checking your proposal (https://github.com/golang/go/issues/16876)
>
> > but could not able to make it. :(
>
> The proposal suggests calling the generated New method on the object.
> Did you try that? If so, what went wrong?
>
> -- elias
>
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Re: [go-nuts] Re: x/mobile: Samples for reverse binding in gomobile
*Thank you very much Elias : with your suggestion it is working fine.*
Just last query:
Currently, I called *static method* of my java class:
package reversebinding;
public class RBinding {
public static String getStringFromJava() {
return "Hello from java !!";
}
}
*Now, I want to create object of this class in go and want to call method
using that object from go. *
I was checking your proposal (https://github.com/golang/go/issues/16876)
but could not able to make it. :(
Can you please help me , how to do that?
*Thanks*.
On Wednesday, September 11, 2019 at 4:36:20 PM UTC+5:30, Elias Naur wrote:
>
> On Wed Sep 11, 2019 at 3:51 AM Jay Sharma wrote:
> >
> >
> > I have one doubt when we build using gomobile in that I am giving the
> > classpath to my .class java file.
> > *Will it be included in .aar or I have to include that .class file along
> > with .aar in my android application. *
> >
>
> The class file is not automatically included, that wasn't clear from my
> earlier
> reply. Please include the class file in your project and try my suggestion
> to
> call your code from Java.
>
> -- elias
>
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Re: [go-nuts] Re: x/mobile: Samples for reverse binding in gomobile
Hi Elias,
The provided logs:
2019-09-10 16:36:54.199 9400-9430/com.sample E/GoLog: 2019/09/10 11:06:54
test.go:134: testFunction [Test]
2019-09-10 16:36:54.199 9400-9430/com.sample E/GoLog: 2019/09/10 11:06:54
test.go:136: [Test] Now going to call a java system function
(System.CurrentTimeMillis())..
2019-09-10 16:36:54.200 9400-9434/com.sample E/GoLog: 2019/09/10 11:06:54
test.go:138: [Test] Called java function return value is: 1568113614199
*In this you can see I am able to call System.CurrentTimeMillis() and
printing in logs.*
*This is the next line of code where I am trying to call my own class java
function from go: *
2019-09-10 16:36:54.200 9400-9434/com.sample E/GoLog: 2019/09/10 11:06:54
test.go:140: [Test] Now going to call my java function
After this log I am actually calling like this:
*RBinding.getStringFromJava() and it is crashing. *
I have one doubt when we build using gomobile in that I am giving the
classpath to my .class java file.
*Will it be included in .aar or I have to include that .class file along
with .aar in my android application. *
Thanks.
On Tuesday, September 10, 2019 at 8:55:47 PM UTC+5:30, Elias Naur wrote:
>
> On Tue Sep 10, 2019 at 4:26 AM Jay Sharma wrote:
> > --=_Part_1258_983331168.1568114760099
> > Content-Type: text/plain; charset="UTF-8"
> >
> > Hello @elias,
> >
> > I tried the following:
> >
> > 1. Created a java class :
> >
> > package reversebinding;
> >
> > public class RBinding {
> > public static String getStringFromJava() {
> > return "Hello from java !!";
> > }
> > }
> >
> > 2. Generated the .class file for this file.
> >
> > 3. Generated the android binding using gomobile tool and used
> > -classpath="Path to my .class file"
> >
> > 4. Binding is generated successfully.
> >
> > *But when I used that generated (.aar) file in my android app and tried
> to
> > trigger the api it is crashing; *
> >
> > 2019-09-10 16:36:54.199 9400-9430/com.sample E/GoLog: 2019/09/10
> 11:06:54
> > test.go:134: testFunction [Test]
> > 2019-09-10 16:36:54.199 9400-9430/com.sample E/GoLog: 2019/09/10
> 11:06:54
> > test.go:136: [Test] Now going to call a java system function
> > (System.CurrentTimeMillis()).
> > 2019-09-10 16:36:54.200 9400-9434/com.sample E/GoLog: 2019/09/10
> 11:06:54
> > test.go:138: [Test] Called java function return value is: 1568113614199
> > 2019-09-10 16:36:54.200 9400-9434/com.sample E/GoLog: 2019/09/10
> 11:06:54
> > test.go:140: [Test] Now going to call my java function.
> > 2019-09-10 16:36:54.203 9400-0/com.sample E/Go: panic: runtime error:
> > invalid memory address or nil pointer dereference
> > 2019-09-10 16:36:54.203 9400-0/com.sample E/Go: [signal SIGSEGV:
> > segmentation violation code=0x1 addr=0x0 pc=0x7568010708]
> > 2019-09-10 16:36:54.203 9400-0/com.sample E/Go: goroutine 17 [running,
> > locked to thread]:
> > 2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
> > test.testFunction(0x400738)
> > 2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
> > /home/test/2019/test/test.go:141 +0x190
> > 2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
> > main.proxytest__testFunction(...)
> > 2019-09-10 16:36:54.203 9400-0/com.sample com.sample E/Go:
> > /tmp/gomobile-work-071468276/src/gobind/go_testmain.go:199
> > 2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
> >
> main._cgoexpwrap_5427a26f9204_proxytest__testFunction(0x8020080280200802)
> > 2019-09-10 16:36:54.203 9400-0/com.sample E/Go: _cgo_gotypes.go:606
> > +0x1c
> > 2019-09-10 16:36:54.204 9400-9423/com.sample A/libc: Fatal signal 6
> > (SIGABRT), code -6 in tid 9423 (Thread-2)
> >
>
> The error is arguably not very helpful. Are you sure there is not another
> error
> before the nil pointer exception? In any case, did you ensure that the
> .class
> is included in the Android apk? An easy check is to try to call your
> method
> from Java before trying from Go.
>
> -- elias
>
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Re: [go-nuts] Re: x/mobile: Samples for reverse binding in gomobile
Just one more information:
I am calling from my go code like this:
RBinding.GetStringFromJava()
On Tuesday, September 10, 2019 at 4:56:00 PM UTC+5:30, Jay Sharma wrote:
>
> Hello @elias,
>
> I tried the following:
>
> 1. Created a java class :
>
> package reversebinding;
>
> public class RBinding {
> public static String getStringFromJava() {
> return "Hello from java !!";
> }
> }
>
> 2. Generated the .class file for this file.
>
> 3. Generated the android binding using gomobile tool and used
> -classpath="Path to my .class file"
>
> 4. Binding is generated successfully.
>
> *But when I used that generated (.aar) file in my android app and tried to
> trigger the api it is crashing; *
>
> 2019-09-10 16:36:54.199 9400-9430/com.sample E/GoLog: 2019/09/10 11:06:54
> test.go:134: testFunction [Test]
> 2019-09-10 16:36:54.199 9400-9430/com.sample E/GoLog: 2019/09/10 11:06:54
> test.go:136: [Test] Now going to call a java system function
> (System.CurrentTimeMillis()).
> 2019-09-10 16:36:54.200 9400-9434/com.sample E/GoLog: 2019/09/10 11:06:54
> test.go:138: [Test] Called java function return value is: 1568113614199
> 2019-09-10 16:36:54.200 9400-9434/com.sample E/GoLog: 2019/09/10 11:06:54
> test.go:140: [Test] Now going to call my java function.
> 2019-09-10 16:36:54.203 9400-0/com.sample E/Go: panic: runtime error:
> invalid memory address or nil pointer dereference
> 2019-09-10 16:36:54.203 9400-0/com.sample E/Go: [signal SIGSEGV:
> segmentation violation code=0x1 addr=0x0 pc=0x7568010708]
> 2019-09-10 16:36:54.203 9400-0/com.sample E/Go: goroutine 17 [running,
> locked to thread]:
> 2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
> test.testFunction(0x400738)
> 2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
> /home/test/2019/test/test.go:141 +0x190
> 2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
> main.proxytest__testFunction(...)
> 2019-09-10 16:36:54.203 9400-0/com.sample com.sample E/Go:
> /tmp/gomobile-work-071468276/src/gobind/go_testmain.go:199
> 2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
> main._cgoexpwrap_5427a26f9204_proxytest__testFunction(0x8020080280200802)
> 2019-09-10 16:36:54.203 9400-0/com.sample E/Go: _cgo_gotypes.go:606
> +0x1c
> 2019-09-10 16:36:54.204 9400-9423/com.sample A/libc: Fatal signal 6
> (SIGABRT), code -6 in tid 9423 (Thread-2)
>
> *Can you please provide you opinion. Let me know if any other information
> is needed. *
>
> Thanks
>
>
> On Monday, September 9, 2019 at 5:40:25 PM UTC+5:30, Elias Naur wrote:
>>
>> On Mon Sep 9, 2019 at 3:09 AM Jay Sharma wrote:
>> >
>> > *Next I want to try with my own classes in java.. I want to define
>> class
>> > and call it from go. *
>> > *Can you please suggest, in that case how to build with gomobile ?*
>> >
>>
>> I think you can use the -classpath option to gomobile.
>>
>> -- elias
>>
>
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Re: [go-nuts] Re: x/mobile: Samples for reverse binding in gomobile
Hello @elias,
I tried the following:
1. Created a java class :
package reversebinding;
public class RBinding {
public static String getStringFromJava() {
return "Hello from java !!";
}
}
2. Generated the .class file for this file.
3. Generated the android binding using gomobile tool and used
-classpath="Path to my .class file"
4. Binding is generated successfully.
*But when I used that generated (.aar) file in my android app and tried to
trigger the api it is crashing; *
2019-09-10 16:36:54.199 9400-9430/com.sample E/GoLog: 2019/09/10 11:06:54
test.go:134: testFunction [Test]
2019-09-10 16:36:54.199 9400-9430/com.sample E/GoLog: 2019/09/10 11:06:54
test.go:136: [Test] Now going to call a java system function
(System.CurrentTimeMillis()).
2019-09-10 16:36:54.200 9400-9434/com.sample E/GoLog: 2019/09/10 11:06:54
test.go:138: [Test] Called java function return value is: 1568113614199
2019-09-10 16:36:54.200 9400-9434/com.sample E/GoLog: 2019/09/10 11:06:54
test.go:140: [Test] Now going to call my java function.
2019-09-10 16:36:54.203 9400-0/com.sample E/Go: panic: runtime error:
invalid memory address or nil pointer dereference
2019-09-10 16:36:54.203 9400-0/com.sample E/Go: [signal SIGSEGV:
segmentation violation code=0x1 addr=0x0 pc=0x7568010708]
2019-09-10 16:36:54.203 9400-0/com.sample E/Go: goroutine 17 [running,
locked to thread]:
2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
test.testFunction(0x400738)
2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
/home/test/2019/test/test.go:141 +0x190
2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
main.proxytest__testFunction(...)
2019-09-10 16:36:54.203 9400-0/com.sample com.sample E/Go:
/tmp/gomobile-work-071468276/src/gobind/go_testmain.go:199
2019-09-10 16:36:54.203 9400-0/com.sample E/Go:
main._cgoexpwrap_5427a26f9204_proxytest__testFunction(0x8020080280200802)
2019-09-10 16:36:54.203 9400-0/com.sample E/Go: _cgo_gotypes.go:606
+0x1c
2019-09-10 16:36:54.204 9400-9423/com.sample A/libc: Fatal signal 6
(SIGABRT), code -6 in tid 9423 (Thread-2)
*Can you please provide you opinion. Let me know if any other information
is needed. *
Thanks
On Monday, September 9, 2019 at 5:40:25 PM UTC+5:30, Elias Naur wrote:
>
> On Mon Sep 9, 2019 at 3:09 AM Jay Sharma wrote:
> >
> > *Next I want to try with my own classes in java.. I want to define class
> > and call it from go. *
> > *Can you please suggest, in that case how to build with gomobile ?*
> >
>
> I think you can use the -classpath option to gomobile.
>
> -- elias
>
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[go-nuts] x/mobile: Samples for reverse binding in gomobile
Hello All, *I can not see any samples for reverse binding (Calling function from go layer of java layer) in gomobile.* Is anybody tried any samples of reverse binding. Thank in advance. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/4e960e3d-e543-4735-a9ba-de23387dff16%40googlegroups.com.
[go-nuts] x/mobile: Launch a android application with given package name [String] in go
Hello All,
*Following is the function written in go:*
func LaunchApplication(packageName string) {
Query :
how can I execute application with given packageName
}
Generated the java binding [.aar] using *gomobile*.
I want to include .aar generated in my android application and call
*LaunchApplication("com.package.name")* from java layer to native go layer
and go layer should run the application.
*In java application*, following is the way to run apk using package name:
Process process = Runtime.getRuntime().exec("am start -n
com.package.name/com.package.name.ActivityName");
I tried the same in go using:
*os.exec()* function but it is giving error that "am not found in the $PATH"
*Is there is any way to do that ?*
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[go-nuts] Re: Regarding string immutablity
*@Jan*, The example you shown it is copying a string to new variable. but my question was related to same variable. I want to know if I have variable : x := "testsring" Now it overwrite the content of same variable x to some other value: x = "new1string" Will it overwrite the same memory or it will create some copy ? @Jake Montgomery, It is about *security*. I have some keys and I want to delete the content of key, when no longer required. Here my API is expecting a string key. On Tuesday, August 28, 2018 at 8:25:27 PM UTC+5:30, Jay Sharma wrote: > > Hi All, > > I went through documentation and many post. Every where it is specified > *strings > are immutable*. > > I have some string : > > x := "teststring" > > > I want to *wipe out/overwrite* the content of this string x from > disk/memory. > > As per me the simplest way to do this: > > x = "" > > > or If I want to overwrite it with some new content, I can do this: [*Here > length of new string is equal to length of old string*] > > x = "new1string" > > > As I am overwriting the content with new content, Is it *inplace > replacement* [same memory is being updated] or a new copy will be created > with new content and old content will be there in the memory ? > > > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[go-nuts] Regarding string immutablity
Hi All, I went through documentation and many post. Every where it is specified *strings are immutable*. I have some string : x := "teststring" I want to *wipe out/overwrite* the content of this string x from disk/memory. As per me the simplest way to do this: x = "" or If I want to overwrite it with some new content, I can do this: [*Here length of new string is equal to length of old string*] x = "new1string" As I am overwriting the content with new content, Is it *inplace replacement* [same memory is being updated] or a new copy will be created with new content and old content will be there in the memory ? -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
