How To Execute Shell Command From Java

In Java, you can use Runtime.getRuntime().exec to execute external shell command :

    p = Runtime.getRuntime().exec("host -t a " + domain);    p.waitFor();     BufferedReader reader =          new BufferedReader(new InputStreamReader(p.getInputStream()));     String line = "";    while ((line = reader.readLine())!= null) {sb.append(line + "\n");    }

1. PING example

Classical example to execute the ping command and print out its output.

ExecuteShellComand.java

package com.mkyong.shell; import java.io.BufferedReader;import java.io.InputStreamReader; public class ExecuteShellComand { public static void main(String[] args) { ExecuteShellComand obj = new ExecuteShellComand(); String domainName = "google.com"; //in mac oxsString command = "ping -c 3 " + domainName; //in windows//String command = "ping -n 3 " + domainName; String output = obj.executeCommand(command); System.out.println(output); } private String executeCommand(String command) { StringBuffer output = new StringBuffer(); Process p;try {p = Runtime.getRuntime().exec(command);p.waitFor();BufferedReader reader =                             new BufferedReader(new InputStreamReader(p.getInputStream()));                         String line = "";while ((line = reader.readLine())!= null) {output.append(line + "\n");} } catch (Exception e) {e.printStackTrace();} return output.toString(); } }

Output

PING google.com (74.125.135.x): 56 data bytes64 bytes from 74.125.135.x: icmp_seq=0 ttl=53 time=8.289 ms64 bytes from 74.125.135.x: icmp_seq=1 ttl=53 time=7.733 ms64 bytes from 74.125.135.x: icmp_seq=2 ttl=53 time=8.343 ms --- google.com ping statistics ---3 packets transmitted, 3 packets received, 0.0% packet lossround-trip min/avg/max/stddev = 7.733/8.122/8.343/0.276 msnull

2. HOST Example
Example to execute shell command host -t a google.com to get all the IP addresses that attached to google.com. Later, we use regular expression to grab all the IP addresses and display it.
P.S “host” command is available in *nix system only.
ExecuteShellComand.java
package com.mkyong.shell; import java.io.BufferedReader;import java.io.InputStreamReader;import java.util.ArrayList;import java.util.List;import java.util.regex.Matcher;import java.util.regex.Pattern; public class ExecuteShellComand { private static final String IPADDRESS_PATTERN = "([01]?\\d\\d?|2[0-4]\\d|25[0-5])" + "\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])" + "\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])" + "\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])"; private static Pattern pattern = Pattern.compile(IPADDRESS_PATTERN);private static Matcher matcher; public static void main(String[] args) { ExecuteShellComand obj = new ExecuteShellComand(); String domainName = "google.com";String command = "host -t a " + domainName; String output = obj.executeCommand(command); //System.out.println(output); List<String> list = obj.getIpAddress(output); if (list.size() > 0) {System.out.printf("%s has address : %n", domainName);for (String ip : list) {System.out.println(ip);}} else {System.out.printf("%s has NO address. %n", domainName);} } private String executeCommand(String command) { StringBuffer output = new StringBuffer(); Process p;try {p = Runtime.getRuntime().exec(command);p.waitFor();BufferedReader reader =                            new BufferedReader(new InputStreamReader(p.getInputStream())); String line = "";while ((line = reader.readLine())!= null) {output.append(line + "\n");} } catch (Exception e) {e.printStackTrace();} return output.toString(); } public List<String> getIpAddress(String msg) { List<String> ipList = new ArrayList<String>(); if (msg == null || msg.equals(""))return ipList; matcher = pattern.matcher(msg);while (matcher.find()) {ipList.add(matcher.group(0));} return ipList;}}


Output
google.com has address : 74.125.135.x74.125.135.x74.125.135.x74.125.135.x74.125.135.x74.125.135.x
转自:http://www.mkyong.com/java/how-to-execute-shell-command-from-java/