Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Questions on Runtime.getRuntime()

Posted on 2006-06-30
7
Medium Priority
?
215 Views
Last Modified: 2010-03-31
Guys couple of quick questions on Runtime.getRuntime()

First question ... waitFor?  Is it onyl used for cleanup?  If not for what?
exitCode = p.waitFor();  abnormal termations?


Second question if I want to obtain the output from running an application this way
I know I get via  InputStreamReader and BufferedReader if I was to loop
through the BufferedReader response

while ( (line = br.readLine()) != null)
{
             response=response+line;
}

it would give me all output from the program correct?  (Assuming no abnormal terminations


public static boolean executeObject(byte[] bs)
      {
            boolean resultcode = false;
            String programdir="";
            String programName="";
            String response="";

            
            
            String[] command = new String[2];
            
            
            
            try
            {
                  programdir="D:/ryno71;
                  programName="ryno71.exe";
            } catch (Exception e1)
            {
                  // TODO Auto-generated catch block
                  e1.printStackTrace();
            }
            
            command[0] = programdir+programName;
            String byte_to_string= new String(bs, 0, bs.length);

            command[1] = byte_to_string;  //put what I am executing with ryno71.exe
            //cmd[2] = "param2";
            
            InputStreamReader isr=null;
            BufferedReader br = null;
            try
            {
                  Runtime program = Runtime.getRuntime();
                  Process p = program.exec(command);
                  InputStream stdin = p.getInputStream();
                  
                  
                  
                  
                  try
                  {
                        
                        isr = new InputStreamReader(stdin);
                  }
                  
                  finally
                  {
                        try
                        {
                              if (isr != null) isr.close();
                        }
                        catch(IOException ie)
                        {
                              
                              ie.printStackTrace();
                              
                        };
                        
                        
                  }
                  
                  try
                  {
                        
                        br = new BufferedReader(isr);
                  }
                  
                  finally
                  {
                        
                        try
                        {
                              if (br != null) br.close();
                        }
                        catch(IOException e)
                        {
                              e.printStackTrace();
                              
                        };
                        
                  }
                  
                  String line=null;
                  while ( (line = br.readLine()) != null)
                  {
                                                  response=response+line;
                                                }
                                                //System.out.println(line);
                  
                  //write abnormal out somewhere here.
                  
                  
                  int exitCode = 0;
                  try
                  {
                  exitCode = p.waitFor();  
                                                /*exitCode <= used for errors if you dont want to
                                                     use a separate thread for Process.getErrorStream ?
                                                    Whats waitFor used for????
                                                 */

                  } catch (InterruptedException e)
                  {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                  }
                  if (exitCode != 0)
                  {
                        resultcode=false;
//                        
                        e1.printStackTrace();
                  }
                                                else
                                                {
                                                          resultcode=true;
                                                }

                  
            } catch (IOException e)
            {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
            }
            
            
            return resultcode;
      }

As always thanks for the input
0
Comment
Question by:ryno71
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 3
7 Comments
 
LVL 86

Accepted Solution

by:
CEHJ earned 500 total points
ID: 17018328
>>exitCode = p.waitFor();  abnormal termations?

Normal *and* abnormal

>>it would give me all output from the program correct?

You need to treat the streams on separate threads. See

http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html
0
 

Author Comment

by:ryno71
ID: 17018483
Thanks for the quick response.  If I am limited in opening additional new threads... (not allowed to open additional threads) what I have would work for normal output, correct?
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 17018498
It's difficult to say whether it would work. Try it out
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 

Author Comment

by:ryno71
ID: 17018507
Would I run into issues if I don't pay attention to the ErrorStream and only worry about the InputStream?
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 17018518
Again it's difficult to say
0
 

Author Comment

by:ryno71
ID: 17019824
thanks nothing abnormal, but might see something if I am playing with large amounts of data.

Have a nice weekend

ryno71
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 17019837
:-)
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This was posted to the Netbeans forum a Feb, 2010 and I also sent it to Verisign. Who didn't help much in my struggles to get my application signed. ------------------------- Start The idea here is to target your cell phones with the correct…
Java functions are among the best things for programmers to work with as Java sites can be very easy to read and prepare. Java especially simplifies many processes in the coding industry as it helps integrate many forms of technology and different d…
Video by: Michael
Viewers learn about how to reduce the potential repetitiveness of coding in main by developing methods to perform specific tasks for their program. Additionally, objects are introduced for the purpose of learning how to call methods in Java. Define …
The viewer will learn how to implement Singleton Design Pattern in Java.
Suggested Courses

618 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question