Movatterモバイル変換

Class SecurityManager

java.lang.Object
- java.lang.SecurityManager

Direct Known Subclasses:
RMISecurityManager
```
public classSecurityManagerextendsObject
```
The security manager is a class that allows applications to implement a security policy. It allows an application to determine, before performing a possibly unsafe or sensitive operation, what the operation is and whether it is being attempted in a security context that allows the operation to be performed. The application can allow or disallow the operation.
TheSecurityManager class contains many methods with names that begin with the wordcheck. These methods are called by various methods in the Java libraries before those methods perform certain potentially sensitive operations. The invocation of such acheck method typically looks like this:
```
     SecurityManager security = System.getSecurityManager();     if (security != null) {         security.checkXXX(argument,  . . . );     }
```
The security manager is thereby given an opportunity to prevent completion of the operation by throwing an exception. A security manager routine simply returns if the operation is permitted, but throws aSecurityException if the operation is not permitted.
The current security manager is set by thesetSecurityManager method in classSystem. The current security manager is obtained by thegetSecurityManager method.
The special methodcheckPermission(java.security.Permission) determines whether an access request indicated by a specified permission should be granted or denied. The default implementation calls
```
   AccessController.checkPermission(perm);
```
If a requested access is allowed,checkPermission returns quietly. If denied, aSecurityException is thrown.
The default implementation of each of the othercheck methods inSecurityManager is to call theSecurityManager checkPermission method to determine if the calling thread has permission to perform the requested operation.
Note that thecheckPermission method with just a single permission argument always performs security checks within the context of the currently executing thread. Sometimes a security check that should be made within a given context will actually need to be done from within adifferent context (for example, from within a worker thread). ThegetSecurityContext method and thecheckPermission method that includes a context argument are provided for this situation. ThegetSecurityContext method returns a "snapshot" of the current calling context. (The default implementation returns an AccessControlContext object.) A sample call is the following:
```
   Object context = null;   SecurityManager sm = System.getSecurityManager();   if (sm != null) context = sm.getSecurityContext();
```
ThecheckPermission method that takes a context object in addition to a permission makes access decisions based on that context, rather than on that of the current execution thread. Code within a different context can thus call that method, passing the permission and the previously-saved context object. A sample call, using the SecurityManagersm obtained as in the previous example, is the following:
```
   if (sm != null) sm.checkPermission(permission, context);
```
Permissions fall into these categories: File, Socket, Net, Security, Runtime, Property, AWT, Reflect, and Serializable. The classes managing these various permission categories arejava.io.FilePermission,java.net.SocketPermission,java.net.NetPermission,java.security.SecurityPermission,java.lang.RuntimePermission,java.util.PropertyPermission,java.awt.AWTPermission,java.lang.reflect.ReflectPermission, andjava.io.SerializablePermission.
All but the first two (FilePermission and SocketPermission) are subclasses ofjava.security.BasicPermission, which itself is an abstract subclass of the top-level class for permissions, which isjava.security.Permission. BasicPermission defines the functionality needed for all permissions that contain a name that follows the hierarchical property naming convention (for example, "exitVM", "setFactory", "queuePrintJob", etc). An asterisk may appear at the end of the name, following a ".", or by itself, to signify a wildcard match. For example: "a.*" or "*" is valid, "*a" or "a*b" is not valid.
FilePermission and SocketPermission are subclasses of the top-level class for permissions (java.security.Permission). Classes like these that have a more complicated name syntax than that used by BasicPermission subclass directly from Permission rather than from BasicPermission. For example, for ajava.io.FilePermission object, the permission name is the path name of a file (or directory).
Some of the permission classes have an "actions" list that tells the actions that are permitted for the object. For example, for ajava.io.FilePermission object, the actions list (such as "read, write") specifies which actions are granted for the specified file (or for files in the specified directory).
Other permission classes are for "named" permissions - ones that contain a name but no actions list; you either have the named permission or you don't.
Note: There is also ajava.security.AllPermission permission that implies all permissions. It exists to simplify the work of system administrators who might need to perform multiple tasks that require all (or numerous) permissions.
SeePermissions in the Java Development Kit (JDK) for permission-related information. This document includes a table listing the various SecurityManagercheck methods and the permission(s) the default implementation of each such method requires. It also contains a table of the methods that require permissions, and for each such method tells which permission it requires.
Since:
1.0
See Also:
ClassLoader,SecurityException,getSecurityManager,setSecurityManager,AccessController,AccessControlContext,AccessControlException,Permission,BasicPermission,FilePermission,SocketPermission,PropertyPermission,RuntimePermission,AWTPermission,Policy,SecurityPermission,ProtectionDomain

Constructor Summary
Constructors
Constructor Description
SecurityManager()
Constructs a newSecurityManager.

Constructors
Constructor	Description
`SecurityManager()`	Constructs a new`SecurityManager`.

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`void`	`checkAccept(String host, int port)`	Throws a`SecurityException` if the calling thread is not permitted to accept a socket connection from the specified host and port number.
`void`	`checkAccess(Thread t)`	Throws a`SecurityException` if the calling thread is not allowed to modify the thread argument.
`void`	`checkAccess(ThreadGroup g)`	Throws a`SecurityException` if the calling thread is not allowed to modify the thread group argument.
`void`	`checkConnect(String host, int port)`	Throws a`SecurityException` if the calling thread is not allowed to open a socket connection to the specified host and port number.
`void`	`checkConnect(String host, int port,Object context)`	Throws a`SecurityException` if the specified security context is not allowed to open a socket connection to the specified host and port number.
`void`	`checkCreateClassLoader()`	Throws a`SecurityException` if the calling thread is not allowed to create a new class loader.
`void`	`checkDelete(String file)`	Throws a`SecurityException` if the calling thread is not allowed to delete the specified file.
`void`	`checkExec(String cmd)`	Throws a`SecurityException` if the calling thread is not allowed to create a subprocess.
`void`	`checkExit(int status)`	Throws a`SecurityException` if the calling thread is not allowed to cause the Java Virtual Machine to halt with the specified status code.
`void`	`checkLink(String lib)`	Throws a`SecurityException` if the calling thread is not allowed to dynamic link the library code specified by the string argument file.
`void`	`checkListen(int port)`	Throws a`SecurityException` if the calling thread is not allowed to wait for a connection request on the specified local port number.
`void`	`checkMulticast(InetAddress maddr)`	Throws a`SecurityException` if the calling thread is not allowed to use (join/leave/send/receive) IP multicast.
`void`	`checkMulticast(InetAddress maddr, byte ttl)`	Deprecated. Use #checkPermission(java.security.Permission) instead
`void`	`checkPackageAccess(String pkg)`	Throws a`SecurityException` if the calling thread is not allowed to access the specified package.
`void`	`checkPackageDefinition(String pkg)`	Throws a`SecurityException` if the calling thread is not allowed to define classes in the specified package.
`void`	`checkPermission(Permission perm)`	Throws a`SecurityException` if the requested access, specified by the given permission, is not permitted based on the security policy currently in effect.
`void`	`checkPermission(Permission perm,Object context)`	Throws a`SecurityException` if the specified security context is denied access to the resource specified by the given permission.
`void`	`checkPrintJobAccess()`	Throws a`SecurityException` if the calling thread is not allowed to initiate a print job request.
`void`	`checkPropertiesAccess()`	Throws a`SecurityException` if the calling thread is not allowed to access or modify the system properties.
`void`	`checkPropertyAccess(String key)`	Throws a`SecurityException` if the calling thread is not allowed to access the system property with the specified`key` name.
`void`	`checkRead(FileDescriptor fd)`	Throws a`SecurityException` if the calling thread is not allowed to read from the specified file descriptor.
`void`	`checkRead(String file)`	Throws a`SecurityException` if the calling thread is not allowed to read the file specified by the string argument.
`void`	`checkRead(String file,Object context)`	Throws a`SecurityException` if the specified security context is not allowed to read the file specified by the string argument.
`void`	`checkSecurityAccess(String target)`	Determines whether the permission with the specified permission target name should be granted or denied.
`void`	`checkSetFactory()`	Throws a`SecurityException` if the calling thread is not allowed to set the socket factory used by`ServerSocket` or`Socket`, or the stream handler factory used by`URL`.
`void`	`checkWrite(FileDescriptor fd)`	Throws a`SecurityException` if the calling thread is not allowed to write to the specified file descriptor.
`void`	`checkWrite(String file)`	Throws a`SecurityException` if the calling thread is not allowed to write to the file specified by the string argument.
`protectedClass<?>[]`	`getClassContext()`	Returns the current execution stack as an array of classes.
`Object`	`getSecurityContext()`	Creates an object that encapsulates the current execution environment.
`ThreadGroup`	`getThreadGroup()`	Returns the thread group into which to instantiate any new thread being created at the time this is being called.

Methods declared in class java.lang.Object
clone,equals,finalize,getClass,hashCode,notify,notifyAll,toString,wait,wait,wait

- Constructor Detail
  - SecurityManager
```
public SecurityManager()
```
    Constructs a newSecurityManager.
    If there is a security manager already installed, this method first calls the security manager'scheckPermission method with theRuntimePermission("createSecurityManager") permission to ensure the calling thread has permission to create a new security manager. This may result in throwing aSecurityException.
    Throws:
    SecurityException - if a security manager already exists and itscheckPermission method doesn't allow creation of a new security manager.
    See Also:
    System.getSecurityManager(),checkPermission,RuntimePermission
- Method Detail
  - getClassContext
```
protected Class<?>[] getClassContext()
```
    Returns the current execution stack as an array of classes.
    The length of the array is the number of methods on the execution stack. The element at index0 is the class of the currently executing method, the element at index1 is the class of that method's caller, and so on.
    Returns:
    the execution stack.
  - getSecurityContext
```
public Object getSecurityContext()
```
    Creates an object that encapsulates the current execution environment. The result of this method is used, for example, by the three-argumentcheckConnect method and by the two-argumentcheckRead method. These methods are needed because a trusted method may be called on to read a file or open a socket on behalf of another method. The trusted method needs to determine if the other (possibly untrusted) method would be allowed to perform the operation on its own.
    The default implementation of this method is to return anAccessControlContext object.
    Returns:
    an implementation-dependent object that encapsulates sufficient information about the current execution environment to perform some security checks later.
    See Also:
    checkConnect,checkRead,AccessControlContext
  - checkPermission
```
public void checkPermission(Permission perm)
```
    Throws aSecurityException if the requested access, specified by the given permission, is not permitted based on the security policy currently in effect.
    This method callsAccessController.checkPermission with the given permission.
    Parameters:
    perm - the requested permission.
    Throws:
    SecurityException - if access is not permitted based on the current security policy.
    NullPointerException - if the permission argument isnull.
    Since:
    1.2
  - checkPermission
```
public void checkPermission(Permission perm,Object context)
```
    Throws aSecurityException if the specified security context is denied access to the resource specified by the given permission. The context must be a security context returned by a previous call togetSecurityContext and the access control decision is based upon the configured security policy for that security context.
    Ifcontext is an instance ofAccessControlContext then theAccessControlContext.checkPermission method is invoked with the specified permission.
    Ifcontext is not an instance ofAccessControlContext then aSecurityException is thrown.
    Parameters:
    perm - the specified permission
    context - a system-dependent security context.
    Throws:
    SecurityException - if the specified security context is not an instance ofAccessControlContext (e.g., isnull), or is denied access to the resource specified by the given permission.
    NullPointerException - if the permission argument isnull.
    Since:
    1.2
    See Also:
    getSecurityContext(),AccessControlContext.checkPermission(java.security.Permission)
  - checkCreateClassLoader
```
public void checkCreateClassLoader()
```
    Throws aSecurityException if the calling thread is not allowed to create a new class loader.
    This method callscheckPermission with theRuntimePermission("createClassLoader") permission.
    If you override this method, then you should make a call tosuper.checkCreateClassLoader at the point the overridden method would normally throw an exception.
    Throws:
    SecurityException - if the calling thread does not have permission to create a new class loader.
    See Also:
    ClassLoader(),checkPermission
  - checkAccess
```
public void checkAccess(Thread t)
```
    Throws aSecurityException if the calling thread is not allowed to modify the thread argument.
    This method is invoked for the current security manager by thestop,suspend,resume,setPriority,setName, andsetDaemon methods of classThread.
    If the thread argument is a system thread (belongs to the thread group with anull parent) then this method callscheckPermission with theRuntimePermission("modifyThread") permission. If the thread argument isnot a system thread, this method just returns silently.
    Applications that want a stricter policy should override this method. If this method is overridden, the method that overrides it should additionally check to see if the calling thread has theRuntimePermission("modifyThread") permission, and if so, return silently. This is to ensure that code granted that permission (such as the JDK itself) is allowed to manipulate any thread.
    If this method is overridden, thensuper.checkAccess should be called by the first statement in the overridden method, or the equivalent security check should be placed in the overridden method.
    Parameters:
    t - the thread to be checked.
    Throws:
    SecurityException - if the calling thread does not have permission to modify the thread.
    NullPointerException - if the thread argument isnull.
    See Also:
    resume,setDaemon,setName,setPriority,stop,suspend,checkPermission
  - checkAccess
```
public void checkAccess(ThreadGroup g)
```
    Throws aSecurityException if the calling thread is not allowed to modify the thread group argument.
    This method is invoked for the current security manager when a new child thread or child thread group is created, and by thesetDaemon,setMaxPriority,stop,suspend,resume, anddestroy methods of classThreadGroup.
    If the thread group argument is the system thread group ( has anull parent) then this method callscheckPermission with theRuntimePermission("modifyThreadGroup") permission. If the thread group argument isnot the system thread group, this method just returns silently.
    Applications that want a stricter policy should override this method. If this method is overridden, the method that overrides it should additionally check to see if the calling thread has theRuntimePermission("modifyThreadGroup") permission, and if so, return silently. This is to ensure that code granted that permission (such as the JDK itself) is allowed to manipulate any thread.
    If this method is overridden, thensuper.checkAccess should be called by the first statement in the overridden method, or the equivalent security check should be placed in the overridden method.
    Parameters:
    g - the thread group to be checked.
    Throws:
    SecurityException - if the calling thread does not have permission to modify the thread group.
    NullPointerException - if the thread group argument isnull.
    See Also:
    destroy,resume,setDaemon,setMaxPriority,stop,suspend,checkPermission
  - checkExit
```
public void checkExit(int status)
```
    Throws aSecurityException if the calling thread is not allowed to cause the Java Virtual Machine to halt with the specified status code.
    This method is invoked for the current security manager by theexit method of classRuntime. A status of0 indicates success; other values indicate various errors.
    This method callscheckPermission with theRuntimePermission("exitVM."+status) permission.
    If you override this method, then you should make a call tosuper.checkExit at the point the overridden method would normally throw an exception.
    Parameters:
    status - the exit status.
    Throws:
    SecurityException - if the calling thread does not have permission to halt the Java Virtual Machine with the specified status.
    See Also:
    exit,checkPermission
  - checkExec
```
public void checkExec(String cmd)
```
    Throws aSecurityException if the calling thread is not allowed to create a subprocess.
    This method is invoked for the current security manager by theexec methods of classRuntime.
    This method callscheckPermission with theFilePermission(cmd,"execute") permission if cmd is an absolute path, otherwise it callscheckPermission withFilePermission("<<ALL FILES>>","execute").
    If you override this method, then you should make a call tosuper.checkExec at the point the overridden method would normally throw an exception.
    Parameters:
    cmd - the specified system command.
    Throws:
    SecurityException - if the calling thread does not have permission to create a subprocess.
    NullPointerException - if thecmd argument isnull.
    See Also:
    Runtime.exec(java.lang.String),Runtime.exec(java.lang.String, java.lang.String[]),Runtime.exec(java.lang.String[]),Runtime.exec(java.lang.String[], java.lang.String[]),checkPermission
  - checkLink
```
public void checkLink(String lib)
```
    Throws aSecurityException if the calling thread is not allowed to dynamic link the library code specified by the string argument file. The argument is either a simple library name or a complete filename.
    This method is invoked for the current security manager by methodsload andloadLibrary of classRuntime.
    This method callscheckPermission with theRuntimePermission("loadLibrary."+lib) permission.
    If you override this method, then you should make a call tosuper.checkLink at the point the overridden method would normally throw an exception.
    Parameters:
    lib - the name of the library.
    Throws:
    SecurityException - if the calling thread does not have permission to dynamically link the library.
    NullPointerException - if thelib argument isnull.
    See Also:
    Runtime.load(java.lang.String),Runtime.loadLibrary(java.lang.String),checkPermission
  - checkRead
```
public void checkRead(FileDescriptor fd)
```
    Throws aSecurityException if the calling thread is not allowed to read from the specified file descriptor.
    This method callscheckPermission with theRuntimePermission("readFileDescriptor") permission.
    If you override this method, then you should make a call tosuper.checkRead at the point the overridden method would normally throw an exception.
    Parameters:
    fd - the system-dependent file descriptor.
    Throws:
    SecurityException - if the calling thread does not have permission to access the specified file descriptor.
    NullPointerException - if the file descriptor argument isnull.
    See Also:
    FileDescriptor,checkPermission
  - checkRead
```
public void checkRead(String file)
```
    Throws aSecurityException if the calling thread is not allowed to read the file specified by the string argument.
    This method callscheckPermission with theFilePermission(file,"read") permission.
    If you override this method, then you should make a call tosuper.checkRead at the point the overridden method would normally throw an exception.
    Parameters:
    file - the system-dependent file name.
    Throws:
    SecurityException - if the calling thread does not have permission to access the specified file.
    NullPointerException - if thefile argument isnull.
    See Also:
    checkPermission
  - checkRead
```
public void checkRead(String file,Object context)
```
    Throws aSecurityException if the specified security context is not allowed to read the file specified by the string argument. The context must be a security context returned by a previous call togetSecurityContext.
    Ifcontext is an instance ofAccessControlContext then theAccessControlContext.checkPermission method will be invoked with theFilePermission(file,"read") permission.
    Ifcontext is not an instance ofAccessControlContext then aSecurityException is thrown.
    If you override this method, then you should make a call tosuper.checkRead at the point the overridden method would normally throw an exception.
    Parameters:
    file - the system-dependent filename.
    context - a system-dependent security context.
    Throws:
    SecurityException - if the specified security context is not an instance ofAccessControlContext (e.g., isnull), or does not have permission to read the specified file.
    NullPointerException - if thefile argument isnull.
    See Also:
    getSecurityContext(),AccessControlContext.checkPermission(java.security.Permission)
  - checkWrite
```
public void checkWrite(FileDescriptor fd)
```
    Throws aSecurityException if the calling thread is not allowed to write to the specified file descriptor.
    This method callscheckPermission with theRuntimePermission("writeFileDescriptor") permission.
    If you override this method, then you should make a call tosuper.checkWrite at the point the overridden method would normally throw an exception.
    Parameters:
    fd - the system-dependent file descriptor.
    Throws:
    SecurityException - if the calling thread does not have permission to access the specified file descriptor.
    NullPointerException - if the file descriptor argument isnull.
    See Also:
    FileDescriptor,checkPermission
  - checkWrite
```
public void checkWrite(String file)
```
    Throws aSecurityException if the calling thread is not allowed to write to the file specified by the string argument.
    This method callscheckPermission with theFilePermission(file,"write") permission.
    If you override this method, then you should make a call tosuper.checkWrite at the point the overridden method would normally throw an exception.
    Parameters:
    file - the system-dependent filename.
    Throws:
    SecurityException - if the calling thread does not have permission to access the specified file.
    NullPointerException - if thefile argument isnull.
    See Also:
    checkPermission
  - checkDelete
```
public void checkDelete(String file)
```
    Throws aSecurityException if the calling thread is not allowed to delete the specified file.
    This method is invoked for the current security manager by thedelete method of classFile.
    This method callscheckPermission with theFilePermission(file,"delete") permission.
    If you override this method, then you should make a call tosuper.checkDelete at the point the overridden method would normally throw an exception.
    Parameters:
    file - the system-dependent filename.
    Throws:
    SecurityException - if the calling thread does not have permission to delete the file.
    NullPointerException - if thefile argument isnull.
    See Also:
    File.delete(),checkPermission
  - checkConnect
```
public void checkConnect(String host,                         int port)
```
    Throws aSecurityException if the calling thread is not allowed to open a socket connection to the specified host and port number.
    A port number of-1 indicates that the calling method is attempting to determine the IP address of the specified host name.
    This method callscheckPermission with theSocketPermission(host+":"+port,"connect") permission if the port is not equal to -1. If the port is equal to -1, then it callscheckPermission with theSocketPermission(host,"resolve") permission.
    If you override this method, then you should make a call tosuper.checkConnect at the point the overridden method would normally throw an exception.
    Parameters:
    host - the host name port to connect to.
    port - the protocol port to connect to.
    Throws:
    SecurityException - if the calling thread does not have permission to open a socket connection to the specifiedhost andport.
    NullPointerException - if thehost argument isnull.
    See Also:
    checkPermission
  - checkConnect
```
public void checkConnect(String host,                         int port,Object context)
```
    Throws aSecurityException if the specified security context is not allowed to open a socket connection to the specified host and port number.
    A port number of-1 indicates that the calling method is attempting to determine the IP address of the specified host name.
    Ifcontext is not an instance ofAccessControlContext then aSecurityException is thrown.
    Otherwise, the port number is checked. If it is not equal to -1, thecontext'scheckPermission method is called with aSocketPermission(host+":"+port,"connect") permission. If the port is equal to -1, then thecontext'scheckPermission method is called with aSocketPermission(host,"resolve") permission.
    If you override this method, then you should make a call tosuper.checkConnect at the point the overridden method would normally throw an exception.
    Parameters:
    host - the host name port to connect to.
    port - the protocol port to connect to.
    context - a system-dependent security context.
    Throws:
    SecurityException - if the specified security context is not an instance ofAccessControlContext (e.g., isnull), or does not have permission to open a socket connection to the specifiedhost andport.
    NullPointerException - if thehost argument isnull.
    See Also:
    getSecurityContext(),AccessControlContext.checkPermission(java.security.Permission)
  - checkListen
```
public void checkListen(int port)
```
    Throws aSecurityException if the calling thread is not allowed to wait for a connection request on the specified local port number.
    This method callscheckPermission with theSocketPermission("localhost:"+port,"listen").
    If you override this method, then you should make a call tosuper.checkListen at the point the overridden method would normally throw an exception.
    Parameters:
    port - the local port.
    Throws:
    SecurityException - if the calling thread does not have permission to listen on the specified port.
    See Also:
    checkPermission
  - checkAccept
```
public void checkAccept(String host,                        int port)
```
    Throws aSecurityException if the calling thread is not permitted to accept a socket connection from the specified host and port number.
    This method is invoked for the current security manager by theaccept method of classServerSocket.
    This method callscheckPermission with theSocketPermission(host+":"+port,"accept") permission.
    If you override this method, then you should make a call tosuper.checkAccept at the point the overridden method would normally throw an exception.
    Parameters:
    host - the host name of the socket connection.
    port - the port number of the socket connection.
    Throws:
    SecurityException - if the calling thread does not have permission to accept the connection.
    NullPointerException - if thehost argument isnull.
    See Also:
    ServerSocket.accept(),checkPermission
  - checkMulticast
```
public void checkMulticast(InetAddress maddr)
```
    Throws aSecurityException if the calling thread is not allowed to use (join/leave/send/receive) IP multicast.
    This method callscheckPermission with thejava.net.SocketPermission(maddr.getHostAddress(), "accept,connect") permission.
    If you override this method, then you should make a call tosuper.checkMulticast at the point the overridden method would normally throw an exception.
    Parameters:
    maddr - Internet group address to be used.
    Throws:
    SecurityException - if the calling thread is not allowed to use (join/leave/send/receive) IP multicast.
    NullPointerException - if the address argument isnull.
    Since:
    1.1
    See Also:
    checkPermission
  - checkMulticast
```
@Deprecated(since="1.4")public void checkMulticast(InetAddress maddr,                           byte ttl)
```
    Deprecated.
    Use #checkPermission(java.security.Permission) instead
    Throws aSecurityException if the calling thread is not allowed to use (join/leave/send/receive) IP multicast.
    This method callscheckPermission with thejava.net.SocketPermission(maddr.getHostAddress(), "accept,connect") permission.
    If you override this method, then you should make a call tosuper.checkMulticast at the point the overridden method would normally throw an exception.
    Parameters:
    maddr - Internet group address to be used.
    ttl - value in use, if it is multicast send. Note: this particular implementation does not use the ttl parameter.
    Throws:
    SecurityException - if the calling thread is not allowed to use (join/leave/send/receive) IP multicast.
    NullPointerException - if the address argument isnull.
    Since:
    1.1
    See Also:
    checkPermission
  - checkPropertiesAccess
```
public void checkPropertiesAccess()
```
    Throws aSecurityException if the calling thread is not allowed to access or modify the system properties.
    This method is used by thegetProperties andsetProperties methods of classSystem.
    This method callscheckPermission with thePropertyPermission("*", "read,write") permission.
    If you override this method, then you should make a call tosuper.checkPropertiesAccess at the point the overridden method would normally throw an exception.
    Throws:
    SecurityException - if the calling thread does not have permission to access or modify the system properties.
    See Also:
    System.getProperties(),System.setProperties(java.util.Properties),checkPermission
  - checkPropertyAccess
```
public void checkPropertyAccess(String key)
```
    Throws aSecurityException if the calling thread is not allowed to access the system property with the specifiedkey name.
    This method is used by thegetProperty method of classSystem.
    This method callscheckPermission with thePropertyPermission(key, "read") permission.
    If you override this method, then you should make a call tosuper.checkPropertyAccess at the point the overridden method would normally throw an exception.
    Parameters:
    key - a system property key.
    Throws:
    SecurityException - if the calling thread does not have permission to access the specified system property.
    NullPointerException - if thekey argument isnull.
    IllegalArgumentException - ifkey is empty.
    See Also:
    System.getProperty(java.lang.String),checkPermission
  - checkPrintJobAccess
```
public void checkPrintJobAccess()
```
    Throws aSecurityException if the calling thread is not allowed to initiate a print job request.
    This method callscheckPermission with theRuntimePermission("queuePrintJob") permission.
    If you override this method, then you should make a call tosuper.checkPrintJobAccess at the point the overridden method would normally throw an exception.
    Throws:
    SecurityException - if the calling thread does not have permission to initiate a print job request.
    Since:
    1.1
    See Also:
    checkPermission
  - checkPackageAccess
```
public void checkPackageAccess(String pkg)
```
    Throws aSecurityException if the calling thread is not allowed to access the specified package.
    During class loading, this method may be called by theloadClass method of class loaders and by the Java Virtual Machine to ensure that the caller is allowed to access the package of the class that is being loaded.
    This method checks if the specified package starts with or equals any of the packages in thepackage.access Security Property. An implementation may also check the package against an additional list of restricted packages as noted below. If the package is restricted,checkPermission(Permission) is called with aRuntimePermission("accessClassInPackage."+pkg) permission.
    If this method is overridden, thensuper.checkPackageAccess should be called as the first line in the overridden method.
    Implementation Note:
    This implementation also restricts all non-exported packages of modules loaded bythe platform class loader or its ancestors. A "non-exported package" refers to a package that is not exported to all modules. Specifically, it refers to a package that either is not exported at all by its containing module or is exported in a qualified fashion by its containing module.
    Parameters:
    pkg - the package name.
    Throws:
    SecurityException - if the calling thread does not have permission to access the specified package.
    NullPointerException - if the package name argument isnull.
    See Also:
    loadClass,getProperty,checkPermission
  - checkPackageDefinition
```
public void checkPackageDefinition(String pkg)
```
    Throws aSecurityException if the calling thread is not allowed to define classes in the specified package.
    This method is called by theloadClass method of some class loaders.
    This method checks if the specified package starts with or equals any of the packages in thepackage.definition Security Property. An implementation may also check the package against an additional list of restricted packages as noted below. If the package is restricted,checkPermission(Permission) is called with aRuntimePermission("defineClassInPackage."+pkg) permission.
    If this method is overridden, thensuper.checkPackageDefinition should be called as the first line in the overridden method.
    Implementation Note:
    This implementation also restricts all non-exported packages of modules loaded bythe platform class loader or its ancestors. A "non-exported package" refers to a package that is not exported to all modules. Specifically, it refers to a package that either is not exported at all by its containing module or is exported in a qualified fashion by its containing module.
    Parameters:
    pkg - the package name.
    Throws:
    SecurityException - if the calling thread does not have permission to define classes in the specified package.
    NullPointerException - if the package name argument isnull.
    See Also:
    ClassLoader.loadClass(String, boolean),getProperty,checkPermission
  - checkSetFactory
```
public void checkSetFactory()
```
    Throws aSecurityException if the calling thread is not allowed to set the socket factory used byServerSocket orSocket, or the stream handler factory used byURL.
    This method callscheckPermission with theRuntimePermission("setFactory") permission.
    If you override this method, then you should make a call tosuper.checkSetFactory at the point the overridden method would normally throw an exception.
    Throws:
    SecurityException - if the calling thread does not have permission to specify a socket factory or a stream handler factory.
    See Also:
    setSocketFactory,setSocketImplFactory,setURLStreamHandlerFactory,checkPermission
  - checkSecurityAccess
```
public void checkSecurityAccess(String target)
```
    Determines whether the permission with the specified permission target name should be granted or denied.
    If the requested permission is allowed, this method returns quietly. If denied, a SecurityException is raised.
    This method creates aSecurityPermission object for the given permission target name and callscheckPermission with it.
    See the documentation forSecurityPermission for a list of possible permission target names.
    If you override this method, then you should make a call tosuper.checkSecurityAccess at the point the overridden method would normally throw an exception.
    Parameters:
    target - the target name of theSecurityPermission.
    Throws:
    SecurityException - if the calling thread does not have permission for the requested access.
    NullPointerException - iftarget is null.
    IllegalArgumentException - iftarget is empty.
    Since:
    1.1
    See Also:
    checkPermission
  - getThreadGroup
```
public ThreadGroup getThreadGroup()
```
    Returns the thread group into which to instantiate any new thread being created at the time this is being called. By default, it returns the thread group of the current thread. This should be overridden by a specific security manager to return the appropriate thread group.
    Returns:
    ThreadGroup that new threads are instantiated into
    Since:
    1.1
    See Also:
    ThreadGroup

Movatterモバイル変換

Class SecurityManager

Constructor Summary

Method Summary

Methods declared in class java.lang.Object

Constructor Detail

SecurityManager

Method Detail

getClassContext

getSecurityContext

checkPermission

checkPermission

checkCreateClassLoader

checkAccess

checkAccess

checkExit

checkExec

checkLink

checkRead

checkRead

checkRead

checkWrite

checkWrite

checkDelete

checkConnect

checkConnect

checkListen

checkAccept

checkMulticast

checkMulticast

checkPropertiesAccess

checkPropertyAccess

checkPrintJobAccess

checkPackageAccess

checkPackageDefinition

checkSetFactory

checkSecurityAccess

getThreadGroup