Need to execute a shell script from java

If you are looking for optimized solution for executing any scripts for your java class, then you can use Jsch with Google Expect4j libraries.

For jsch, go to http://www.jcraft.com/jsch/
For Expect4j, go to http://code.google.com/p/expect4j/

Following is small code sample for log in and executing file fro remote java class.

private Expect4j SSH(String hostname, String username,String password, int port) throws Exception {
    JSch jsch = new JSch();
    Session session = jsch.getSession(username, hostname, port);
    if (password != null) {         
        session.setPassword(password);
    }
    Hashtable<String,String> config = new Hashtable<String,String>();
    config.put("StrictHostKeyChecking", "no");
    session.setConfig(config);
    session.connect(60000);
    channel = (ChannelShell) session.openChannel("shell");
    Expect4j expect = new Expect4j(channel.getInputStream(), channel.getOutputStream());
    channel.connect();      
    return expect;
}  

This method will open up SSH stream to remote server which will be used by expect4j for sending commands.

private boolean executeCommands() {
        boolean isSuccess = true;
        Closure closure = new Closure() {
            public void run(ExpectState expectState) throws Exception {
                buffer.append(expectState.getBuffer());             
                expectState.exp_continue();
            }
        };
        List<Match> lstPattern =  new ArrayList<Match>();
        String[] regEx = SSHConstants.linuxPromptRegEx;  
        if (regEx != null && regEx.length > 0) {
            synchronized (regEx) {
                for (String regexElement : regEx) {//list of regx like,  :>, /> etc. it is possible command prompts of your remote machine
                    try {
                        RegExpMatch mat = new RegExpMatch(regexElement, closure);
                        lstPattern.add(mat);                        
                    } catch (MalformedPatternException e) {                     
                        return false;
                    } catch(Exception e) {                      
                        return false;
                    }
                }
                lstPattern.add(new EofMatch( new Closure() { // should cause entire page to be collected
                    public void run(ExpectState state) {
                    }
                }));
                lstPattern.add(new TimeoutMatch(defaultTimeOut, new Closure() {
                    public void run(ExpectState state) {
                    }
                }));
            }
        }
        try {
            Expect4j expect = SSH(objConfig.getHostAddress(), objConfig.getUserName(), objConfig.getPassword(), SSHConstants.SSH_PORT);
            expect.setDefaultTimeout(defaultTimeOut);       
            if(isSuccess) {
                for(String strCmd : lstCmds)
                    isSuccess = isSuccess(lstPattern,strCmd);
            }
            boolean isFailed = checkResult(expect.expect(lstPattern));
            return !isFailed;
        } catch (Exception ex) {            
            return false;
        } finally {
            closeConnection();
        }
    }


private boolean isSuccess(List<Match> objPattern,String strCommandPattern) {
        try {   
            boolean isFailed = checkResult(expect.expect(objPattern));

            if (!isFailed) {
                expect.send(strCommandPattern);         
                expect.send("\r");              
                return true;
            } 
            return false;
        } catch (MalformedPatternException ex) {    
            return false;
        } catch (Exception ex) {
            return false;
        }
    }

Hope this help.
Thanks.

new ProcessBuilder("ssh", "root@opmer3", command_).start();