Call a C code in Java

How is the best way to call a C code in Java ???
Socket? Dll? ...
And how can i do it ????
I am creating a Interpreter in C. But the simulation is apresented
graphically in a applet (Java).
Thanks

Look at the JNI section of the Java tutorial.
http://java.sun.com/docs/books/tutorial/native1.1/index.html

Similar Messages

How to call C/C++ - Code from Java?

I would like to know if it is possible to call C or C++ - Code from Java and how to do.

In short, yes you can do this.
Have a look at http://java.sun.com/docs/books/tutorial/native1.1/concepts/index.html
to see how...
Good luck!

How to call a .bat file from java code?

How to call a .bat file from java code? and how can i pass parameters to that .bat file?
Thanks in advance

thanks for ur reply
but still i am getting the same error.
I am trying to run a .bat file of together tool, my code looks like below
import java.lang.Runtime;
import java.lang.Process;
import java.io.File;
class SysCall{
     public static void main(String args[]){
          String cmd="D://Borland//Together6.2//bin//Together.bat -script:com.togethersoft.modules.qa.QA -metrics out:D://MySamples//Metrics// -fmt:html D://Borland//Together6.2//samples//java//CashSales//CashSales.tpr";
          //String path="D://Borland//Together6.2//bin//Together.bat ";
          Runtime r= Runtime.getRuntime(); //Declare the system call
          try{
               System.out.println("Before batch is called");
               Process p=r.exec(cmd);
               System.out.println(" Exit value =" + p.exitValue());
               System.out.println("After batch is called");
          /*can produce errors which must be caught*/
          catch(Exception e) {
               e.printStackTrace();
               System.out.println (e.toString());
I am getting the below exception
Before batch is called
java.lang.IllegalThreadStateException: process has not exited
at java.lang.Win32Process.exitValue(Native Method)
at SysCall.main(SysCall.java:17)
java.lang.IllegalThreadStateException: process has not exited

Problem while Calling a CGI pgm From Java with code sample

Hey guys,
I am calling a CGI program from java servlet, while calling cgi program I am passing encoded(Base64) content via post process,
My problem is the encoded data is not posted as expected, the encoded data is corrupting. But when I send encoded data in a text file, cgi program is perfectly decoding and working fine.
Here I am doing Base64 encoding as per requirement, I cannot avoid this encoding.
My doubt is about OutputStreamWriter constructor argument , In OutputStream Constructor I am passing one argument is OutputStream object and another argument is encoding type. I tried with ASCII, US-ASCII & UTF-8 .
My code is as follows, please help me to resolve this issue.
URL url = new URL("CGI server path");
URLConnection urlConnection = url.openConnection();
urlConnection.setDoOutput(true);
OutputStream os = urlConnection.getOutputStream();
BufferedOutputStream buffer = new BufferedOutputStream(os);
OutputStreamWriter writer = new
OutputStreamWriter(buffer, "US-ASCII");
writer.write(encodedPDF-Content);
writer.write("\r\n");
writer.flush();
writer.close();
here encodedPDF-Content is String and it's size is 9565 bytes

Whenever you read something in java into string (with Reader implementation) it expects source to contain text in encoding you specified. It then decodes it and makes 16 bit unicode string from it. Whenever you store string using Writers it does reverse operation with specified encoding (may be different than this which you used to read source) and stores text as a sequence of bytes made of 16 bit unicode string. So, passing text back and forth between programs with the help of files or I/O you can make mistake at both reading and writing encoding. Check for it.
Now, when C programm or other application reads file it may take another assumptions about encoding or may even completly ignore it and read source as a binary file. Then, if you have a source text as a file and have to pass it to other application never do it using Reader/Writer. User raw InputStream/OutputStream instead what will preserve all information unchanged.
here encodedPDF-Content is String and it's size is 9565 byteHow id you get this info? String.length() gets you how many chars is in it, it will be half the number of bytes. If you see your input file beeing 9565 bytes long, see my above statements.

Calling Customer code in java application

Hi,
in my java application running on WAS 6.40 I want to call some customer code.
Basically I create a data structure (DOM XML tree) and want to pass this to customer code to be able to modify it as needed.
My idea would be to define an interface which would than be implemented by customer java classes. But how do I load these classes?
In theory I would create a configuration table in my app where the customer would specify the classname of his classes implementing this interface and I would do a Class.forName("...")
But those classes will be unknown to my application'S classloader, right? Because they won't be deployed with my application and I can't have references as I do not know if and what the customer will deploy. What's the best approach to this? WOuld EJBs help better?
Thanks
Bruno

Hi Bruno,
We did this for our application. We needed a weak reference from our deployable DC to a specific DC (e.g. DC\customerExit) The customer then creates this DC and adds their classes to it. Since it is a weak reference, it does not need to exist for your application to work. You can use the customizing to be able to lookup the specific class name that they created.
hope this helps,
Rich

How to call web-service using only java code

Hello, how to call web-service using only java code. I can call it from BPM process or Web Dynpro Java Application, but if I need to call it from ejb component?

I'm found answer:
Java and SAP Portal blog: How to call web service from java code example

How to call IAC Iview from WebDynpro java code

Hi Team,
I am tring to call IAC Iview from WebDynpro Java code. we are passing value but blank page displayed and there is no error show on error log.
Below is Java Code which i am calling.
public void wdDoInit()
      try {
            String strURL = "portal_content/TestSRM/iView/TestSRM";                           //WDProtocolAdapter.getProtocolAdapter().getRequestParameter("application");
             String random = WDProtocolAdapter.getProtocolAdapter().getRequestObject().getParameter("random_code");
             //wdContext.currentContextElement().setRandomNumber(random);
//below we are call URL
WDPortalNavigation.navigateAbsolute("ROLES://portal_content/TestSRM/iView/TestSRM?VAL="+random,WDPortalNavigationMode.SHOW_INPLACE,(String)null, (String)null,
                   WDPortalNavigationHistoryMode.NO_DUPLICATIONS,(String)null,(String)null, " ");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
I am passing value from URL.
http://<host Name>:<port>/webdynpro/resources/local/staruser/StarUser?random_code=111111111
when we call above URL we getting blank screen.
Regards
Pankaj Kamble

Hi Vinod,
read this document (from pages 7 ).
<a href="https://www.sdn.sap.comhttp://www.sdn.sap.comhttp://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/b5380089-0c01-0010-22ae-bd9fa40ddc62">https://www.sdn.sap.comhttp://www.sdn.sap.comhttp://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/b5380089-0c01-0010-22ae-bd9fa40ddc62</a>
In addition lok at these links: (Navigation Between Web Dynpro Applications in the Portal)
<a href="http://help.sap.com/saphelp_erp2005/helpdata/en/ae/36d93f130f9115e10000000a155106/frameset.htm">http://help.sap.com/saphelp_erp2005/helpdata/en/ae/36d93f130f9115e10000000a155106/frameset.htm</a>
<a href="http://help.sap.com/saphelp_erp2004/helpdata/en/b5/424f9c88970f48ba918ad68af9a656/frameset.htm">http://help.sap.com/saphelp_erp2004/helpdata/en/b5/424f9c88970f48ba918ad68af9a656/frameset.htm</a>
It may be helpful for you.
Best regards,
Gianluca Barile

Calling native Objective C code from Java Script

Hi,
I want to call native objective C code from Java script.
I know one way by using : webView:shouldStartLoadWithRequest:navigationType
Is there another way of doing same?
Thanks,
Ganesh Pisal
Vavni Inc

Are any of those threads calling java code? If yes then are you calling the Attach method?

How to call SAP Webservice in standalone java program

Hi,
In our Java application, we want to use the SAP Webservices. I dont know much about authentication mechanism used by SAP. Can any one please help me with any sample code how to Call SAP webservice in Standalone Jave Program. I searched alot on the web regarding this, but helpless. Please help me.
Thanks,
Mohan

Hi Mohan,
You need an account for the ES Workplace. I'm afraid this is not free, e.g. check [SAP NetWeaver, Composition Subscription|https://www.sdn.sap.com/irj/sdn/subscriptions/composition].
But I thought you wanted to play with a WSDL [you already had at hand|Sample code to access BAPI Web services from JAVA required;?

Problem calling two perl modules from java in seperate threads(JVM CRASHES)

Dear Friends,
I have one severe problem regarding calling perl modules from java
I had to call two perl modules simultaneously (i.e.) from two threads,,, but jvm crashes when one of the perl calls is exiting earlier
I am unable to spot out why ....
For calling perl from java ...., We are first calling C code from java using JNI and then Perl code from C
All works fine if we call only one perl call at a time.... If we call them in a synchronized manner the JVM is not crashing .... But we don't want blocking..
The following is the code snippet
<JAVA FILE>
class Sample
     static {
          System.loadLibrary("xyz"); // Here xyz is the library file generated by compiling c code
     public native void call_PrintList();
     public native void call_PrintListNew();
     Sample()
          new Thread1(this).start();
     public static void main(String args[])
          System.out.println("In the main Method");
          new Sample().call_PrintList();
     class Thread1 extends Thread
          Sample sample;
          Thread1(Sample sam)
               sample=sam;
          public void run()
               sample.call_PrintListNew();
}<C FILE>
#include <EXTERN.h>
#include <perl.h>
static PerlInterpreter *my_perl;
static char * words[] = {"alpha", "beta", "gamma", "delta", NULL } ;
static void
call_PrintList(){
     printf("\nIn the Call method of string.c\n");
        char *wor[] = {"hello", "sudha", NULL } ;
           char *my_argv[] = { "", "string.pl" };
           PERL_SYS_INIT3(&argc,&argv,&env);
           my_perl = perl_alloc();
               PL_perl_destruct_level = 1; //// We have mentioned this also and tried removing destruct call
           perl_construct( my_perl );
           perl_parse(my_perl, NULL, 2, my_argv, (char**)NULL);
          PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
           perl_run(my_perl);
     dSP ;
        perl_call_argv("PrintList", G_DISCARD, wor) ;
PL_perl_destruct_level = 1;
//     perl_destruct(my_perl);
//          perl_free(my_perl);
//           PERL_SYS_TERM();
static void
call_PrintListNew(){
printf("In the new call method\n");
char *wor[] = {"Hiiiiiiiiiiiiiii", "Satyam123333", NULL } ;
        char *my_argv[] = { "", "string.pl" };
        PERL_SYS_INIT3(&argc,&argv,&env);
        my_perl = perl_alloc();
PL_perl_destruct_level = 1;
        perl_construct( my_perl );
        perl_parse(my_perl, NULL, 2, my_argv, (char**)NULL);
        PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
        perl_run(my_perl);
        dSP ;
        perl_call_argv("PrintListNew", G_DISCARD, wor) ;
PL_perl_destruct_level = 1;
//      perl_destruct(my_perl);
//      perl_free(my_perl);
   //     PERL_SYS_TERM();
void callNew()
call_PrintListNew();
void call ( )
call_PrintList();
//char *wor[] = {"hello","sudha",NULL};
/*   char *my_argv[] = { "", "string.pl" };
      PERL_SYS_INIT3(&argc,&argv,&env);
      my_perl = perl_alloc();
      perl_construct( my_perl );
      perl_parse(my_perl, NULL, 2, my_argv, (char**)NULL);
     PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
      perl_run(my_perl);*/
   //   call_PrintList();                      /*** Compute 3 ** 4 ***/
/*      perl_destruct(my_perl);
      perl_free(my_perl);
      PERL_SYS_TERM();*/
    }And Finally the perl code
sub PrintList
            my(@list) = @_ ;
            foreach (@list) { print "$_\n" }
sub PrintListNew
            my(@list) = @_ ;
            foreach (@list) { print "$_\n" }
        }Please help me in this regard

Dear Friends,
I have one severe problem regarding calling perl modules from java
I had to call two perl modules simultaneously (i.e.) from two threads,,, but jvm crashes when one of the perl calls is exiting earlier
I am unable to spot out why ....
For calling perl from java ...., We are first calling C code from java using JNI and then Perl code from C
All works fine if we call only one perl call at a time.... If we call them in a synchronized manner the JVM is not crashing .... But we don't want blocking..
The following is the code snippet
<JAVA FILE>
class Sample
     static {
          System.loadLibrary("xyz"); // Here xyz is the library file generated by compiling c code
     public native void call_PrintList();
     public native void call_PrintListNew();
     Sample()
          new Thread1(this).start();
     public static void main(String args[])
          System.out.println("In the main Method");
          new Sample().call_PrintList();
     class Thread1 extends Thread
          Sample sample;
          Thread1(Sample sam)
               sample=sam;
          public void run()
               sample.call_PrintListNew();
}<C FILE>
#include <EXTERN.h>
#include <perl.h>
static PerlInterpreter *my_perl;
static char * words[] = {"alpha", "beta", "gamma", "delta", NULL } ;
static void
call_PrintList(){
     printf("\nIn the Call method of string.c\n");
        char *wor[] = {"hello", "sudha", NULL } ;
           char *my_argv[] = { "", "string.pl" };
           PERL_SYS_INIT3(&argc,&argv,&env);
           my_perl = perl_alloc();
               PL_perl_destruct_level = 1; //// We have mentioned this also and tried removing destruct call
           perl_construct( my_perl );
           perl_parse(my_perl, NULL, 2, my_argv, (char**)NULL);
          PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
           perl_run(my_perl);
     dSP ;
        perl_call_argv("PrintList", G_DISCARD, wor) ;
PL_perl_destruct_level = 1;
//     perl_destruct(my_perl);
//          perl_free(my_perl);
//           PERL_SYS_TERM();
static void
call_PrintListNew(){
printf("In the new call method\n");
char *wor[] = {"Hiiiiiiiiiiiiiii", "Satyam123333", NULL } ;
        char *my_argv[] = { "", "string.pl" };
        PERL_SYS_INIT3(&argc,&argv,&env);
        my_perl = perl_alloc();
PL_perl_destruct_level = 1;
        perl_construct( my_perl );
        perl_parse(my_perl, NULL, 2, my_argv, (char**)NULL);
        PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
        perl_run(my_perl);
        dSP ;
        perl_call_argv("PrintListNew", G_DISCARD, wor) ;
PL_perl_destruct_level = 1;
//      perl_destruct(my_perl);
//      perl_free(my_perl);
   //     PERL_SYS_TERM();
void callNew()
call_PrintListNew();
void call ( )
call_PrintList();
//char *wor[] = {"hello","sudha",NULL};
/*   char *my_argv[] = { "", "string.pl" };
      PERL_SYS_INIT3(&argc,&argv,&env);
      my_perl = perl_alloc();
      perl_construct( my_perl );
      perl_parse(my_perl, NULL, 2, my_argv, (char**)NULL);
     PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
      perl_run(my_perl);*/
   //   call_PrintList();                      /*** Compute 3 ** 4 ***/
/*      perl_destruct(my_perl);
      perl_free(my_perl);
      PERL_SYS_TERM();*/
    }And Finally the perl code
sub PrintList
            my(@list) = @_ ;
            foreach (@list) { print "$_\n" }
sub PrintListNew
            my(@list) = @_ ;
            foreach (@list) { print "$_\n" }
        }Please help me in this regard

How can i call a CGI script from java?

The subject pretty much says it all. I want to call a perl cgi script so i can read from/write to files on a server. I don't know how to sign applets and this would be the easiest way for me, if someone could please tell me.

Let me get this clear. Basically what u want to do is to just call a URL, right?
U can do it by using the following code:
import java.applet.*;
import java.net.*;
import java.io.*;
public class testhttp
public static void main(String[] args)
try
URL url = new URL ("http://../testcgi.cfm");
HttpURLConnection cxn =
(HttpURLConnection)url.openConnection();
cxn.setRequestMethod("POST");
cxn.setUseCaches(false);
cxn.setDoOutput(true);
cxn.setDoInput(true);
ByteArrayOutputStream bytes = new
ByteArrayOutputStream(400);
PrintWriter writer = new PrintWriter (bytes,true);
writer.print("application=map&release=1&items=prog1");
writer.flush();
cxn.setRequestProperty("Content-
Length",String.valueOf(bytes.size()));
cxn.setRequestProperty("Content-
Type","application/x-www-form-urlencoded");
bytes.writeTo(cxn.getOutputStream());
System.out.println(bytes);
String currentLine;
BufferedReader in = new BufferedReader (new
InputStreamReader(cxn.getInputStream(),"8859_1"));
while((currentLine = in.readLine()) != null) {
System.out.println(currentLine); }
catch(Exception e) { e.printStackTrace(); }
There is also a library called HTTP client which can be found at:
http://www.innovation.ch/java/HTTPClient/index.html
It's very simple to use and the documentation is all there, but their web server seems to be down right now.
Anyway, hope my post helps.

How to call a shell script in Java ?

Hi there,
i try to call a shell script in java but it wont work.
please can anybody help me.
my Code :
import java.io.*;
public class SendMessage{
Runtime rt;
public SendMessage(){
rt = Runtime.getRuntime();
public void send(){
try{
rt.exec("sendMessage.sh");
System.out.println("Message was Send");
catch(IOException ex)
ex.printStackTrace();
the file called sendMessage.sh is also stored in the same directory as the class File.
the exception never cames up but the script also never starts.
what is wrong ??? :-((
need help !
}

rt.exec("sendMessage.sh");Oh, sorry, I didn't see that you tried under UNIX.
BTW you should check for the OS - this stuff is very os and os release dependent.
I have not experimented with this under unix.
But something must interpret that sendMessage.sh file.
Perhaps the hash bang info is used by exec() (did you put a
#!/bin/sh as first line in your .sh file?
If not, try
rt.exec("/bin/sh sendMessage.sh");Regards,
Marc

Calling a Web Service in Java

Hi All,
I would like to call a webservice using a java code?
How can i go about it?
Should i directly use the SOAPEnvelope Interface and call the wsdl?
Rgds
Aditya

Google for a JAX-WS tutorial.

Calling a Web Service from Java

Our java guru (who is out sick....AHHHH) created all the calls that are needed to access the web service that he has running. For example the call getLongList(String user, String password) will return a list of all outstanding transactions. He made a jar file that has service has class files for PortType, Service, Service Locator and Soap Binding stub.
How do I call this web service from java? Do I have to import it into my classpath? or just call these parameters from within my java code?

never mind...i got it

Calling a Web Service from Java Webdynpro

Hi,
Can any one give me step by setp details on how to call a Web Service from Java Webdynpro ?
I tried creating a model using Import Web Service Model but when I completed creating the model, I got some errors as shown below.
Error The method setRouteGeometryLineArray(double[][]) in the type Trip is not applicable for the arguments (double[]) ComplexType_Trip.java WS_INVOKE/gen_wdp/packages/com/cintas/test/model/p1 line 249
thanks
SBK

Hi SBK,
I assume you may already have read the [help guide|http://help.sap.com/saphelp_nw70/helpdata/EN/81/12703e5da3e946e10000000a114084/content.htm] This gives a pretty good idea of how to do it (step by step).
Is there a typo in the error you pasted?
Error The method setRouteGeometryLineArray(double][) in the type Trip is not applicable for the arguments (double[]) ComplexType_Trip.java WS_INVOKE/gen_wdp/packages/com/cintas/test/model/p1 line 249
The square brackets [] after double in the method call appear to be reversed. Is that also in the code? or just a mistake here?
Hope this points you in the right direction.
BRgds,
Simon

Call a C code in Java

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