Using winRAR with Java (help)

Newbie & Debugging Questions
#1

Using winRAR with java. I’m trying to use winrar through command line.

If I run this code the window’s title is “rar a compressed text.txt” (read “start”'s help file and it said that if a command is not provided, but a string is then the string will be the title of the window). I put winRAR in my PATH so I can run rar.exe from anywhere in cmd, but It’s not seeing it as a command, just a string.

Runtime.getRuntime().exec(new String[] {"cmd.exe", "/c", "start", "rar a compressed text.txt"});

also tried

Runtime.getRuntime().exec(new String[] {"cmd.exe", "/c", "start", "rar", "a compressed text.txt"});

which will run rar.exe (blazes through the parameters) but then disappears without RARing text.txt -> compressed.rar

Any thoughts?

#2
  1. does it work on the command-line?
  2. do you grab and read the STDERR/STDOUT from the process, so they will don’t suffer from full buffers, blocking WinRAR ?
#3

  1. Works in command line

  2. Not to sure what you are asking, so probably no

Here’s the code:

import java.io.File;
import java.io.IOException;

public class rarAllFolders
{
	
	public static void main(String args[])
	{
		File directory = new File(System.getProperty("user.dir"));
		File folders[] = directory.listFiles();

		for(int i = 0; i < folders.length; i++)
		{
			if(folders[i].getName().indexOf(".") == -1)
			{
				//rar all the folders
				try {
					System.out.println(folders[i].getName()+"                  " + folders[i]);
					Runtime.getRuntime().exec(new String[] {"cmd.exe", "/c", "start", "rar", "a compressed text.txt"}); //" + folders[i].getName() + " " + folders[i].getName()});
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		
	}
	
}

This program when run will rar all the folders in the current directory.

#4

Runtime.exec() returns a java.lang.Process object. You can use that to read the error and output streams to see what is going on.

#5

Thank You

I’m having trouble with buffered readers right now (probably because it’s late), but so far it just returns “-1” I don’t think i’m doing it right.
Been looking at

[url]http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html?page=4[/url]

Will play with it more in the morning, thank you ;D

Now the code looks like

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;

public class rarAllFolders
{
	
	public static void main(String args[])
	{
		File directory = new File(System.getProperty("user.dir"));
		File folders[] = directory.listFiles();

		for(int i = 0; i < folders.length; i++)
		{
			if(folders[i].getName().indexOf(".") == -1)
			{
				//rar all the folders
				try {
					System.out.println(folders[i].getName()+"                  " + folders[i]);
					Process pros = Runtime.getRuntime().exec(new String[] {"cmd.exe", "/c", "start", "rar a compressed text.txt"}); //" + folders[i].getName() + " " + folders[i].getName()});
			        BufferedReader in = new BufferedReader(
                            new InputStreamReader(
                            pros.getInputStream()));
				    String inputLine;
				
				    while ((inputLine = in.readLine()) != null) 
				        System.out.println(inputLine);
				    in.close();
				
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		
	}
	
}

But I don’t understand
grab and read the STDERR/STDOUT from the process, so they will don’t suffer from full buffers, blocking WinRAR

#6

you will need to read the error stream and output stream in a seperate thread as currently you are not actually running the process!

in pusedo code:


Consumer errConsumer=new Comsumer(pros.getErrStream());
Consumer outConsumer=new Comsumer(pros.getOutStream());

(new Thread(errConusmer,"ErrConsumer").start();
(new Thread(outConusmer.,"OutConsumer").start();

boolean result=pros.waitforexit();

if (result!=0) System.out.println("process failed");





class Consumer imlements Runnable
{
  // this is where you read in and postenially display from the stream;
}
#7

I’ll have to try this tomorrow. I am really thankful that no one has just spat the code at me, it’s nice thinking every once and awhile :stuck_out_tongue: