Cum să rulați comenzile terminalelor Windows, Linux, macOS în Java și să returnați rezultatul complet

Publicat: 2019-02-26

Executați comenzile Linux mkdir, ls -ltra și ping în Java

Executarea unei system command este relativ simplă – odată ce ați văzut-o făcută prima dată.

Implică utilizarea a două clase Java, clasa Runtime și clasa Process. Practic, utilizați exec method a clasei Runtime pentru a rula comanda ca proces separat.

Invocarea metodei exec returnează un obiect Process pentru gestionarea subprocesului. Apoi utilizați getInputStream() și getErrorStream() ale obiectului Process pentru a citi rezultatul normal al comenzii și rezultatul de eroare al comenzii. Ceea ce faceți cu rezultatul comenzii executate depinde în întregime de dvs. și de aplicația pe care o creați.

Metodele ProcessBuilder.start() și Runtime.exec creează un proces nativ și returnează o instanță a unei subclase de Process care poate fi folosită pentru a controla procesul și a obține informații despre acesta.

Clasa Process oferă metode pentru efectuarea intrărilor din proces, efectuarea ieșirii către proces, așteptarea finalizării procesului, verificarea stării de ieșire a procesului și distrugerea (uciderea) procesului.

Metodele care creează procese pot să nu funcționeze bine pentru procese speciale pe anumite platforme native, cum ar fi procesele native de ferestre, procesele demon, procesele Win16/DOS pe Microsoft Windows sau scripturile shell.

În mod implicit, subprocesul creat nu are propriul terminal sau consolă. Toate operațiunile sale standard I/O (adică stdin, stdout, stderr) vor fi redirecționate către procesul părinte, unde pot fi accesate prin fluxurile obținute folosind metodele getOutputStream() , getInputStream() și getErrorStream() .

Procesul părinte folosește aceste fluxuri pentru a alimenta intrarea și a obține rezultate din subproces. Deoarece unele platforme native oferă doar o dimensiune limitată a bufferului pentru fluxurile de intrare și de ieșire standard, eșecul de a scrie prompt fluxul de intrare sau de a citi fluxul de ieșire al subprocesului poate cauza blocarea subprocesului sau chiar blocarea.

Mai jos sunt două exemple simple Java pentru referință.

Exemplul-1. Executați mkdir, ls -ltra și ping în Java

  • Creați fișierul CrunchifyCommandJava.java
  • Executați mkdir /Users/ashah/Desktop/new-folder
  • Executați ls -ltra /Library
  • Executați ping crunchify.com

CrunchifyCommandJava.java
Java
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package crunchify . com . tutorials ;
 
import java . io . BufferedReader ;
import java . io . IOException ;
import java . io . InputStream ;
import java . io . InputStreamReader ;
 
/**
* @author Crunchify.com
* Execute Linux commands using Java. We are executing mkdir, ls -ltra and ping in this tutorial
*/
 
public class CrunchifyCommandJava {
public printOutput getStreamWrapper ( InputStream is , String type ) {
return new printOutput ( is , type ) ;
}
 
public static void main ( String [ ] args ) {
 
Runtime rt = Runtime . getRuntime ( ) ;
CrunchifyCommandJava rte = new CrunchifyCommandJava ( ) ;
printOutput errorReported , outputMessage ;
 
try {
Process proc = rt . exec ( "mkdir /Users/ashah/Desktop/new-folder" ) ;
errorReported = rte . getStreamWrapper ( proc . getErrorStream ( ) , "ERROR" ) ;
outputMessage = rte . getStreamWrapper ( proc . getInputStream ( ) , "OUTPUT" ) ;
errorReported . start ( ) ;
outputMessage . start ( ) ;
} catch ( IOException e ) {
e . printStackTrace ( ) ;
}
 
try {
Process proc = rt . exec ( "ls -ltra /Library" ) ;
errorReported = rte . getStreamWrapper ( proc . getErrorStream ( ) , "ERROR" ) ;
outputMessage = rte . getStreamWrapper ( proc . getInputStream ( ) , "OUTPUT" ) ;
errorReported . start ( ) ;
outputMessage . start ( ) ;
} catch ( IOException e ) {
e . printStackTrace ( ) ;
}
try {
Process proc = rt . exec ( "ping crunchify.com" ) ;
errorReported = rte . getStreamWrapper ( proc . getErrorStream ( ) , "ERROR" ) ;
outputMessage = rte . getStreamWrapper ( proc . getInputStream ( ) , "OUTPUT" ) ;
errorReported . start ( ) ;
outputMessage . start ( ) ;
} catch ( IOException e ) {
e . printStackTrace ( ) ;
}
 
}
 
private class printOutput extends Thread {
InputStream is = null ;
 
printOutput ( InputStream is , String type ) {
this . is = is ;
}
 
public void run ( ) {
String s = null ;
try {
BufferedReader br = new BufferedReader (
new InputStreamReader ( is ) ) ;
while ( ( s = br . readLine ( ) ) ! = null ) {
System . out . println ( s ) ;
}
} catch ( IOException ioe ) {
ioe . printStackTrace ( ) ;
}
}
}
}

Asigurați-vă că schimbați calea în mod corespunzător în programul de mai sus, conform setărilor sistemului dvs.

Ieșire consola Eclipse:

Doar rulați programul de mai sus ca o aplicație Java și veți vedea un rezultat similar.

result
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mkdir: /Users/ashah/Desktop/new-file-created.txt: File created
 
 
total 0
drwxr-xr-x    3 root  wheel    96 Aug 17  2018 Compositions
drwxr-xr-x@   2 root  wheel    64 Aug 17  2018 GPUBundles
drwxr-xr-x    2 root  wheel    64 Aug 17  2018 SystemProfiler
drwxr-xr-x    2 root  wheel    64 Aug 17  2018 ColorPickers
-rw-r--r--    1 root  wheel     0 Aug 17  2018 .localized
drwxr-xr-x    2 root  wheel    64 Aug 17  2018 StartupItems
drwxr-xr-x    3 root  wheel    96 Aug 17  2018 Speech
drwxr-xr-x    4 root  wheel   128 Aug 17  2018 Ruby
drwxr-xr-x@   2 root  wheel    64 Aug 17  2018 CoreAnalytics
drwxr-xr-x    3 root  wheel    96 Aug 17  2018 DirectoryServices
drwxr-xr-x    5 root  wheel   160 Aug 17  2018 WebServer
drwxr-xr-x    3 root  wheel    96 Aug 17  2018 Perl
drwxr-xr-x    2 root  wheel    64 Aug 17  2018 ScriptingAdditions
drwxr-xr-x    2 root  wheel    64 Aug 17  2018 Keyboard Layouts
drwxr-xr-x    3 root  wheel    96 Aug 17  2018 Graphics
drwxr-xr-x    3 root  wheel    96 Aug 17  2018 Python
drwxr-xr-x    8 root  wheel   256 Oct 11 16:51 User Pictures
drwxr-xr-x    3 root  wheel    96 Oct 11 16:51 Screen Savers
drwxr-xr-x   51 root  wheel  1632 Oct 11 16:51 Desktop Pictures
drwxr-xr-x    2 root  wheel    64 Oct 18 18:51 Contextual Menu Items
drwxr-xr-x    2 root  wheel    64 Oct 18 18:51 Components
drwxr-xr-x    5 root  wheel   160 Oct 21 16:03 OpenDirectory
drwxr-xr-x    2 root  wheel    64 Oct 23 20:43 Input Methods
drwxr-xr-x    4 root  wheel   128 Oct 29 23:49 Video
drwxr-xr-x    3 root  wheel    96 Nov  5 21:20 Messages
drwxr-xr-x@   3 root  wheel    96 Nov 12 22:37 MessageTracer
drwxr-xr-x    3 root  wheel    96 Nov 12 22:55 CoreMediaIO
drwxr-xr-x    3 root  wheel    96 Nov 29 23:38 Sandbox
drwxr-xr-x    3 root  wheel    96 Nov 29 23:38 Filesystems
drwxr-xr-x    8 root  wheel   256 Nov 29 23:40 Image Capture
drwxr-xr-x    4 root  wheel   128 Nov 29 23:41 Java
drwxr-xr-x    4 root  wheel   128 Nov 29 23:41 QuickTime
drwxr-xr-x   10 root  wheel   320 Nov 29 23:45 Scripts
drwxrwxr-t  182 root  admin  5824 Nov 29 23:47 Fonts
drwxr-xr-x    4 root  wheel   128 Nov 29 23:49 QuickLook
drwxr-xr-x    4 root  wheel   128 Nov 29 23:49 Spotlight
drwxr-xr-x   37 root  wheel  1184 Nov 29 23:50 Modem Scripts
drwxr-xr-x    4 root  wheel   128 Feb 11 13:00 ColorSync
drwxr-xr-x    4 root  wheel   128 Feb 11 13:04 Security
drwxr-xr-x    8 root  wheel   256 Feb 11 13:04 PDF Services
drwxr-xr-x    3 root  wheel    96 Feb 11 13:05 Catacomb
drwxr-xr-x    9 root  wheel   288 Feb 11 13:05 Frameworks
drwxr-xr-x    3 root  wheel    96 Feb 11 13:05 Automator
drwxr-xr-x   10 root  wheel   320 Feb 11 13:05 Audio
drwxr-xr-x    3 root  wheel    96 Feb 11 13:05 Tanium
drwxr-xr-x+  68 root  wheel  2176 Feb 11 13:05 .
drwxr-xr-x    3 root  admin    96 Feb 11 13:05 Developer
drwxr-xr-x    8 root  wheel   256 Feb 11 13:05 Documentation
drwxr-xr-x    4 root  wheel   128 Feb 11 13:05 DropboxHelperTools
drwxrwxr-x   14 root  admin   448 Feb 11 13:07 Receipts
drwxr-xr-x    4 root  wheel   128 Feb 11 13:07 SystemMigration
drwxr-xr-x@   4 root  wheel   128 Feb 11 13:10 StagedExtensions
drwxr-xr-x   14 root  wheel   448 Feb 11 18:26 Widgets
drwxr-xr-x   13 root  wheel   416 Feb 11 18:26 Extensions
drwxr-xr-x   29 root  wheel   928 Feb 11 18:35 ..
drwxr-xr-x    9 root  wheel   288 Feb 17 12:38 Logs
drwxrwxrwt   11 root  admin   352 Feb 22 13:29 Caches
drwxr-xr-x   11 root  wheel   352 Feb 22 13:36 LaunchAgents
drwxr-xr-x    2 root  wheel    64 Feb 22 13:36 PreferencePanes
drwxr-xr-x    9 root  wheel   288 Feb 22 13:36 Internet Plug-Ins
drwxr-xr-t    7 root  wheel   224 Feb 22 13:36 PrivilegedHelperTools
drwxr-xr-x   18 root  wheel   576 Feb 22 13:36 LaunchDaemons
drwxr-xr-x   25 root  admin   800 Feb 22 16:03 Application Support
dr-xr-xr-x    9 root  wheel   288 Feb 25 10:24 Printers
drwxr-xr-x@   5 root  wheel   160 Feb 25 10:24 Updates
drwxr-xr-x   10 root  wheel   320 Feb 25 14:12 Keychains
drwxr-xr-x   25 root  wheel   800 Feb 26 08:07 Managed Preferences
drwxr-xr-x   67 root  wheel  2144 Feb 26 08:07 Preferences
 
 
PING crunchify.com (35.197.114.216): 56 data bytes
64 bytes from 35.197.114.216: icmp_seq=0 ttl=54 time=70.275 ms
64 bytes from 35.197.114.216: icmp_seq=1 ttl=54 time=73.876 ms
64 bytes from 35.197.114.216: icmp_seq=2 ttl=54 time=68.134 ms
64 bytes from 35.197.114.216: icmp_seq=3 ttl=54 time=75.951 ms
64 bytes from 35.197.114.216: icmp_seq=4 ttl=54 time=70.205 ms

Exemplul-2.

  • CrunchifyRunCommand.java
  • Executați comanda ps -few pentru a obține lista tuturor proceselor care rulează pe sistemul dumneavoastră.

CrunchifyRunCommand.java
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package crunchify . com . tutorials ;
 
import java . io . BufferedReader ;
import java . io . IOException ;
import java . io . InputStreamReader ;
 
/**
* @author Crunchify.com
* Execute ps -few command in Java to get list of all processes
*/
 
public class CrunchifyRunCommand {
 
public static void main ( String [ ] args ) {
String s = null ;
 
try {
 
// Process provides control of native processes started by ProcessBuilder.start and Runtime.exec.
// getRuntime() returns the runtime object associated with the current Java application.
Process p = Runtime . getRuntime ( ) . exec ( "ps -few" ) ;
 
BufferedReader stdInput = new BufferedReader ( new InputStreamReader ( p . getInputStream ( ) ) ) ;
BufferedReader stdError = new BufferedReader ( new InputStreamReader ( p . getErrorStream ( ) ) ) ;
 
// read the output from the command
System . out . println ( "Here is the standard output of the command:\n" ) ;
while ( ( s = stdInput . readLine ( ) ) ! = null ) {
System . out . println ( s ) ;
}
 
// read any errors from the attempted command
System . out . println ( "Here is the standard error of the command (if any):\n" ) ;
while ( ( s = stdError . readLine ( ) ) ! = null ) {
System . out . println ( s ) ;
}
 
System . exit ( 0 ) ;
} catch ( IOException e ) {
System . out . println ( "exception happened - here's what I know: " ) ;
e . printStackTrace ( ) ;
System . exit ( - 1 ) ;
}
}
}

Ieșire consola Eclipse:

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Here is the standard output of the command :
 
   UID   PID   PPID    C STIME   TTY           TIME CMD
     0      1      0    0 Fri09PM ? ?          7 : 14.76 / sbin / launchd
     0      44      1    0 Fri09PM ? ?          0 : 09.67 / usr / sbin / syslogd
     0      45      1    0 Fri09PM ? ?          0 : 12.95 / usr / libexec / UserEventAgent ( System )
     0      49      1    0 Fri09PM ? ?          0 : 04.41 / System / Library / PrivateFrameworks / Uninstall . framework / Resources / uninstalld
     0      50      1    0 Fri09PM ? ?          0 : 26.75 / usr / libexec / kextd
     0      51      1    0 Fri09PM ? ?          2 : 00.76 / System / Library / Frameworks / CoreServices . framework / Versions / A / Frameworks / FSEvents . framework / Versions / A / Support / fseventsd
     0      53      1    0 Fri09PM ? ?          4 : 16.25 / usr / local / jamf / bin / jamf launchDaemon - enforceRestrictions - monitorNetworkStateChanges
     0      54      1    0 Fri09PM ? ?          0 : 01.29 / System / Library / PrivateFrameworks / MediaRemote . framework / Support / mediaremoted
   55      57      1    0 Fri09PM ? ?          0 : 01.23 / System / Library / CoreServices / appleeventsd -- server
     0      58      1    0 Fri09PM ? ?          4 : 21.14 / usr / sbin / systemstats -- daemon
     0      60      1    0 Fri09PM ? ?          0 : 41.10 / usr / libexec / configd
     0      61      1    0 Fri09PM ? ?          1 : 03.98 / System / Library / CoreServices / powerd . bundle / powerd
     0      62      1    0 Fri09PM ? ?          0 : 00.89 / Library / Application Support / JAMF / Jamf . app / Contents / MacOS / JamfDaemon . app / Contents / MacOS / JamfDaemon
     0      65      1    0 Fri09PM ? ?          0 : 43.84 / usr / libexec / logd
     0      66      1    0 Fri09PM ? ?          0 : 00.02 / usr / libexec / keybagd - t 15
     0      73      1    0 Fri09PM ? ?          3 : 26.45 / System / Library / Frameworks / CoreServices . framework / Frameworks / Metadata . framework / Support / mds
   240      74      1    0 Fri09PM ? ?          0 : 00.11 / System / Library / CoreServices / iconservicesd
     0      75      1    0 Fri09PM ? ?          0 : 03.39 / usr / libexec / diskarbitrationd
     0      79      1    0 Fri09PM ? ?          0 : 00.73 / System / Library / CoreServices / backupd . bundle / Contents / Resources / backupd - helper - launchd
     0      80      1    0 Fri09PM ? ?          0 : 03.84 / usr / libexec / coreduetd
     0      84      1    0 Fri09PM ? ?          2 : 30.59 / usr / libexec / opendirectoryd
     0      85      1    0 Fri09PM ? ?          0 : 17.45 / System / Library / PrivateFrameworks / ApplePushService . framework / apsd
     0      86      1    0 Fri09PM ? ?          0 : 00.67 / System / Library / PrivateFrameworks / Noticeboard . framework / Versions / A / Resources / nbstated
     0      87      1    0 Fri09PM ? ?          0 : 16.91 / System / Library / CoreServices / launchservicesd
   266      88      1    0 Fri09PM ? ?          0 : 06.48 / usr / libexec / timed
     0      89      1    0 Fri09PM ? ?          0 : 25.37 / usr / sbin / securityd - i
   213      90      1    0 Fri09PM ? ?          0 : 01.16 / System / Library / PrivateFrameworks / MobileDevice . framework / Versions / A / Resources / usbmuxd - launchd
   205      92      1    0 Fri09PM ? ?          0 : 59.64 / usr / libexec / locationd
     0      94      1    0 Fri09PM ? ?          0 : 00.08 autofsd
   244      95      1    0 Fri09PM ? ?          0 : 03.06 / usr / libexec / displaypolicyd - k 1
     0      98      1    0 Fri09PM ? ?          0 : 11.56 / usr / libexec / dasd
     0      99      1    0 Fri09PM ? ?          0 : 00.71 / System / Library / PrivateFrameworks / Heimdal . framework / Helpers / kdc
     0    103      1    0 Fri09PM ? ?          0 : 00.87 / Library / Tanium / TaniumClient / TaniumClient - d
110048994    104      1    0 Fri09PM ? ?          0 : 34.02 / System / Library / CoreServices / loginwindow . app / Contents / MacOS / loginwindow console
     0    105      1    0 Fri09PM ? ?          0 : 00.76 / System / Library / CoreServices / logind
     0    106      1    0 Fri09PM ? ?          0 : 00.66 / System / Library / PrivateFrameworks / GenerationalStorage . framework / Versions / A / Support / revisiond
     0    107      1    0 Fri09PM ? ?          0 : 00.03 / usr / sbin / KernelEventAgent
     0    109      1    0 Fri09PM ? ?          1 : 58.55 / usr / sbin / bluetoothd
   261    110      1    0 Fri09PM ? ?          13 : 48.55 / usr / libexec / hidd
     0    112      1    0 Fri09PM ? ?          0 : 06.37 / usr / libexec / corebrightnessd -- launchd
     0    113      1    0 Fri09PM ? ?          0 : 04.23 / usr / libexec / AirPlayXPCHelper
     0    114      1    0 Fri09PM ? ?          1 : 07.01 / usr / sbin / notifyd
   241    116      1    0 Fri09PM ? ?          0 : 11.70 / usr / sbin / distnoted daemon
     0    119      1    0 Fri09PM ? ?          0 : 03.99 / usr / libexec / amfid
     0    123      1    0 Fri09PM ? ?          0 : 09.47 / usr / libexec / syspolicyd
     0    124      1    0 Fri09PM ? ?          0 : 05.81 / System / Library / Frameworks / Security . framework / Versions / A / XPCServices / authd . xpc / Contents / MacOS / authd
     0    142      1    0 Fri09PM ? ?          1 : 31.63 / usr / sbin / cfprefsd daemon
     0    143      1    0 Fri09PM ? ?          0 : 23.54 / System / Library / CoreServices / coreservicesd
     0    166      1    0 Fri09PM ? ?          0 : 21.34 / System / Library / PrivateFrameworks / CoreDuetContext . framework / Resources / contextstored

Acestea sunt câteva dintre procesele care rulează pe MacBook Pro. Mai sunt destul de multe, dar lipite foarte puține.

Sper că acest tutorial vă ajută să rulați orice comenzi de terminale Linux, macOS folosind un program Java simplu. Anunță-mă pentru orice întrebări.