How to get the output from .jar execution in python codes?
Question: I'm programming the python module that executes SQL to DBMS and retrieves
data. I'm trying to use jdbc jar files instead of native DB drivers. I'm
wondering how to executes jar file in python and get output from jar
execution. And I'd like to know how to pass SQL string to jar argument. Here
is the simplified code. Any help is greatly appreciated.

[ java code ]

    
    
    public class GetDBResults {
        public static void main(String[] args) {
    
            // return sql results
            for(int i=0; i<=100; i++){
                // Is this the proper way to generate the output?
                System.out.println(i+"/t"+i*100+1);
        }
      }
    }
    

[ python code ]

    
    
    subprocess.call( [ 'java','-jar','./GET_DB_DATA.jar' )
    
    # how to get results from jar execution?
    # how to pass SQL string to jar execution?
    


Answer: You can read the output through pipe:

    
    
    >>> from subprocess import Popen, PIPE, STDOUT
    >>> p = Popen(['java', '-jar', './GET_DB_DATA.jar'], stdout=PIPE, stderr=STDOUT)
    >>> for line in p.stdout:
        print line
    

As regards passing string to stdin, you can achieve it this way:

    
    
    >>> p = Popen(['cat'], stdin=PIPE, stdout=PIPE, stderr=STDOUT)
    >>> stdout, stderr = p.communicate(input='passed_string')
    >>> print stdout
    passed_string
    

