In Java come impostare l'autorizzazione del file su un file utilizzando PosixFilePermission? Comprensione del comando chmod
Pubblicato: 2021-06-28
Come impostare l'autorizzazione ai file in Java? Ecco un semplice esempio di configurazione dell'autorizzazione file su qualsiasi file fornito.
Se fai parte della business unit Operazioni di qualsiasi azienda, è molto importante automatizzare il flusso di lavoro di distribuzione, il flusso di lavoro di analisi e così via.
A volte il tuo programma Java esce con un'eccezione se tenti di eseguire qualche comando e in qualche modo per un determinato file non hai il permesso di eseguire il file di script.
Nel nostro caso, è il file Crunchify.sh .
Ecco un semplice programma Java che mostra come impostare l'autorizzazione file su un determinato file.
CrunchifySetFilePermission.java
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package crunchify . com . java . tutorials ; import java . io . IOException ; import java . nio . file . Files ; import java . nio . file . Paths ; import java . nio . file . attribute . PosixFilePermission ; import java . util . HashSet ; import java . util . Set ; import java . io . File ; /** * @author Crunchify.com * In Java how to Set File Permission on a File using PosixFilePermission? Understanding chmod command. */ public class CrunchifySetFilePermission { public static void main ( String [ ] args ) { // File class: An abstract representation of file and directory pathnames. // User interfaces and operating systems use system-dependent pathname strings to name files and directories. // This class presents an abstract, system-independent view of hierarchical pathnames. File file = new File ( "/Users/app/Download/crunchify.txt" ) ; /* -------------------------- Set Permission: 455 ----------------------- */ // A convenience method to set the owner's execute permission for this abstract pathname. // On some platforms it may be possible to start the Java virtual machine with special privileges that allow it to execute files that are not marked executable. file . setExecutable ( false ) ; // public boolean setExecutable(boolean executable) // A convenience method to set the owner's read permission for this abstract pathname. // On some platforms it may be possible to start the Java virtual machine with special privileges that allow it to read files that are marked as unreadable. file . setReadable ( false ) ; // A convenience method to set the owner's write permission for this abstract pathname. // On some platforms it may be possible to start the Java virtual machine with special privileges that allow it to modify files that disallow write operations. file . setWritable ( true ) ; /* -------------------------- Set Permission: 777 ----------------------- */ // public boolean setExecutable(boolean executable, boolean ownerOnly) file . setExecutable ( true , false ) ; file . setReadable ( true , false ) ; file . setWritable ( true , false ) ; // using PosixFilePermission to set file permissions 777. PosixFilePermission - defines the bits for use with the permissions attribute. // The PosixFilePermissions class defines methods for manipulating set of permissions // HashSet: Constructs a new, empty set; the backing HashMap instance has default initial capacity (16) and load factor (0.75). Set < PosixFilePermission > crunchifyPermissions = new HashSet < PosixFilePermission > ( ) ; // add() Adds the specified element to this set if it is not already present (optional operation). // More formally, adds the specified element e to this set if the set contains no element e2 such that Objects.equals(e, e2). // If this set already contains the element, the call leaves the set unchanged and returns false. // In combination with the restriction on constructors, this ensures that sets never contain duplicate elements. /* -------------------------- OWNER Permissions ----------------------- */ // Read permission, owner. crunchifyPermissions . add ( PosixFilePermission . OWNER_READ ) ; // Write permission, owner. crunchifyPermissions . add ( PosixFilePermission . OWNER_WRITE ) ; // Execute/search permission, owner. crunchifyPermissions . add ( PosixFilePermission . OWNER_EXECUTE ) ; /* -------------------------- GROUP Permissions ----------------------- */ // PosixFilePermission: Defines the bits for use with the permissions attribute. // The PosixFilePermissions class defines methods for manipulating set of permissions. // Read permission, group. crunchifyPermissions . add ( PosixFilePermission . GROUP_READ ) ; // Write permission, group. crunchifyPermissions . add ( PosixFilePermission . GROUP_WRITE ) ; // Execute/search permission, group. crunchifyPermissions . add ( PosixFilePermission . GROUP_EXECUTE ) ; /* -------------------------- OTHERS Permissions ----------------------- */ // Read permission, others. crunchifyPermissions . add ( PosixFilePermission . OTHERS_READ ) ; // Write permission, others. crunchifyPermissions . add ( PosixFilePermission . OTHERS_WRITE ) ; // Execute/search permission, others. crunchifyPermissions . add ( PosixFilePermission . OTHERS_EXECUTE ) ; try { // Sets a file's POSIX permissions. // The path parameter is associated with a FileSystem that supports the PosixFileAttributeView. This attribute view provides access to file // attributes commonly associated with files on file systems used by operating systems that implement the Portable Operating System Interface (POSIX) family of standards. Files . setPosixFilePermissions ( Paths . get ( "/Users/app/Download/crunchify.sh" ) , crunchifyPermissions ) ; // Paths: This class consists exclusively of static methods that return a Path by converting a path string or URI. System . out . println ( "File permission set successfully..." ) ; } catch ( IOException e ) { // Signals that an I/O exception of some sort has occurred. This class is the general class of exceptions produced by failed or interrupted I/O operations. e . printStackTrace ( ) ; } } } |
Basta eseguire sopra il programma Java e dovresti vedere il permesso del file Crunchify.sh come di seguito.
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- rwxrwxrwx 1 crunchify crunchify 65 Jun 23 14 : 42 crunchify . sh |
Se rimuovi o commenti sotto 3 file, cambierà l'autorizzazione come di seguito:
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// crunchifyPermissions.add(PosixFilePermission.OTHERS_READ); // crunchifyPermissions.add(PosixFilePermission.OTHERS_WRITE); // crunchifyPermissions.add(PosixFilePermission.OTHERS_EXECUTE); |
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- rwxrwx --- 1 crunchify crunchify 65 Jun 23 14 : 42 crunchify . sh |
Comprendiamo le autorizzazioni dei file Linux:
Ecco un elenco di tutti i permessi:
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Facci sapere se riscontri problemi durante l'esecuzione del programma sopra.
