How to pass a return value from a jar file to a batch file

[simhadri1985]

Hello All,
                I am running a jar (test.jar) file from a batch file(mybatch.bat) using the command "java -jar test.jar input1". The jar is executed properly. Now in a method in the jar file i am setting a flag bit(true/false) in an if condition. I want to retrieve this value in to batch file(mybatch.bat) which called the jar file and store it in a variable in the same batch file. In this batch file I will put an if condition which will run another jar. The second batch will be called only if the IF condition in the batch file is satisfied.

I am struggling to retrieve the flag bit value from the first jar into the same batch file after the execution of first jar is completed.

[Salmon Trout]

if the jar file can echo to the console (stdout) then you can use FOR to capture the output, or if it can write a file you can read that file.

[simhadri1985]

Suppose If i have the code like this,

class  Test
{
   public static void main(String[] args)
   {
    Test test = new Test();
    int ret = test.doNothing();
System.out.println("------------ ret ------------"+ret);
   }

   int doNothing(){
      int i = 33;
      return i;
   }
}

Now if the ret value is printed on the console as :

------------ ret ------------"33

Now how can i capture the value 33. Can you please provide me the code for that.

[Salmon Trout]

Did you miss a double quote off the beginning of your specimen output?

Did you mean

"------------ ret ------------"33

Or did you mean

------------ ret ------------33

?

Are the quotes actually present in the console output?

[simhadri1985]

Sorry.

I mean

------------ ret -----------33

[Salmon Trout]

By setting the token delimiter to be the minus sign - we can separate the second token from the output and put it into a variable

Please try this

Code: [Select]

for /f "tokens=1-2 delims=-" %%A in ( ' java -jar test.jar input1 ' ) do set token2=%%B
echo The second token is %token2%


[simhadri1985]

This is working. Thank you.


But now I wanted to print the value directly using:

System.out.println(ret);

Now I have just the value 33.

So without using deliminators how can i directly capture this value

[Salmon Trout]

I do not understand what you are asking.

[BatchFileBasics]

i believe he wants to capture the output with out deliminators 

[simhadri1985]

In the previous case when the output in the console is

------------ ret ------------33

So you have given the code which uses deliminators


Now i modified my java program like this


class  Test
{
   public static void main(String[] args)
   {
    Test test = new Test();
    int ret = test.doNothing();
System.out.println(ret);
   }

   int doNothing(){
      int i = 33;
      return i;
   }
}


which will just print the value:

33


Now what is the code to just store the value "33" in a variable in the batch file.

[BatchFileBasics]

ohh,

Code: [Select]

for /f "tokens=1-2" %%A in ( ' java -jar test.jar input1 ' ) do set token2=%%B
echo The second token is %token2%
just remove the delims

[simhadri1985]

Thank you very much. Will this works if the batch file in executed in silent mode.

Actually When i perfrom some action in my application this bat file will be run in silent mode. I mean user can not see any command prompt window open. This batch file will be copied from server into user's local PC in C:\temp path and will be run in a hidden mode.

So is it possible to capture the value "33" in this case.

[BatchFileBasics]

so your saying is it possible to capture the "33" in 'silent mode'?
yes.

or do you want to know how to make it in 'silent mode'?

[simhadri1985]

I just wanted to know is it possible to capture the value 33 with the code which you have given

[Salmon Trout]

I used delimiters and tokens because you showed the java output to be in this format:


------token1-------token2


and you said you wanted token2

 

if the output is just one single string then the code to capture the output becomes simpler.

Code: [Select]

for /f "delims=" %%A in ( ' java -jar test.jar input1 ' ) do set retvalue=%%A