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java.lang.Object | +----java.lang.SecurityManager
The SecurityManager
class contains many methods with names that begin with the word check
. These methods are called by various methods in the Java libraries before those methods perform certain potentially sensitive operations. The invocation of such a check 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 a SecurityException
if the operation is not permitted. The only exception to this convention is checkTopLevelWindow
, which returns a boolean
value.
The current security manager is set by the setSecurityManager
method in class System
. The current security manager is obtained by the getSecurityManager
method.
The default implementation of each of the check
XXX methods is to assume that the caller does not have permission to perform the requested operation.
true
if there is a security check in progress; false
otherwise. SecurityManager
. SecurityException
if the calling thread is not permitted to accept a socket connection from the specified host and port number. SecurityException
if the calling thread is not allowed to modify the thread argument. SecurityException
if the calling thread is not allowed to modify the thread group argument. SecurityException
if the calling thread is not allowed to open a socket connection to the specified host and port number. SecurityException
if the specified security context is not allowed to open a socket connection to the specified host and port number. SecurityException
if the calling thread is not allowed to create a new class loader. SecurityException
if the calling thread is not allowed to delete the specified file. SecurityException
if the calling thread is not allowed to create a subprocess. SecurityException
if the calling thread is not allowed to cause the Java Virtual Machine to halt with the specified status code. SecurityException
if the calling thread is not allowed to dynamic link the library code specified by the string argument file. SecurityException
if the calling thread is not allowed to wait for a connection request on the specified local port number. SecurityException
if the calling thread is not allowed to access the package specified by the argument. SecurityException
if the calling thread is not allowed to define classes in the package specified by the argument. SecurityException
if the calling thread is not allowed to access or modify the system properties. SecurityException
if the calling thread is not allowed to access the system property with the specified key
name. SecurityException
if the calling thread is not allowed to read from the specified file descriptor. SecurityException
if the calling thread is not allowed to read the file specified by the string argument. SecurityException
if the specified security context is not allowed to read the file specified by the string argument. 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
. false
if the calling thread is not trusted to bring up the top-level window indicated by the window
argument. SecurityException
if the calling thread is not allowed to write to the specified file descriptor. SecurityException
if the calling thread is not allowed to write to the file specified by the string argument. null
. protected boolean inCheck
true
if there is a security check in progress; false
otherwise.protected SecurityManager()
SecurityManager
. An application is not allowed to create a new security manager if there is already a current security manager. public boolean getInCheck()
inCheck
field. This field should contain true
if a security check is in progress; false
otherwise. protected native Class[] getClassContext()
The length of the array is the number of methods on the execution stack. The element at index 0
is the class of the currently executing method, the element at index 1
is the class of that method's caller, and so on.
protected native ClassLoader currentClassLoader()
null
if there is no occurrence on the stack of a method from a class defined using a class loader. protected Class currentLoadedClass()
protected native int classDepth(String name)
-1
if such a frame cannot be found. protected native int classLoaderDepth()
-1
if there is no occurrence of a method from a class defined using a class loader. protected boolean inClass(String name)
true
if a method from a class with the specified name is on the execution stack; false
otherwise. protected boolean inClassLoader()
null
. true
if a method from a class defined using a class loader is on the execution stack. public Object getSecurityContext()
checkConnect
method and by the two-argument checkRead
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.
public void checkCreateClassLoader()
SecurityException
if the calling thread is not allowed to create a new class loader. The checkCreateClassLoader
method for class SecurityManager
always throws a SecurityException
.
public void checkAccess(Thread g)
SecurityException
if the calling thread is not allowed to modify the thread argument. This method is invoked for the current security manager by the stop
, suspend
, resume
, setPriority
, setName
, and setDaemon
methods of class Thread
.
The checkAccess
method for class SecurityManager
always throws a SecurityException
.
public void checkAccess(ThreadGroup g)
SecurityException
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 the setDaemon
, setMaxPriority
, stop
, suspend
, resume
, and destroy
methods of class ThreadGroup
.
The checkAccess
method for class SecurityManager
always throws a SecurityException
.
public void checkExit(int status)
SecurityException
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 the exit
method of class Runtime
. A status of 0
indicates success; other values indicate various errors.
The checkExit
method for class SecurityManager
always throws a SecurityException
.
public void checkExec(String cmd)
SecurityException
if the calling thread is not allowed to create a subprocess. This method is invoked for the current security manager by the exec
methods of class Runtime
.
The checkExec
method for class SecurityManager
always throws a SecurityException
.
public void checkLink(String lib)
SecurityException
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 methods load
and loadLibrary
of class Runtime
.
The checkLink
method for class SecurityManager
always throws a SecurityException
.
public void checkRead(FileDescriptor fd)
SecurityException
if the calling thread is not allowed to read from the specified file descriptor. The checkRead
method for class SecurityManager
always throws a SecurityException
.
public void checkRead(String file)
SecurityException
if the calling thread is not allowed to read the file specified by the string argument. The checkRead
method for class SecurityManager
always throws a SecurityException
.
public void checkRead(String file, Object context)
SecurityException
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 to getSecurityContext
. The checkRead
method for class SecurityManager
always throws a SecurityException
.
public void checkWrite(FileDescriptor fd)
SecurityException
if the calling thread is not allowed to write to the specified file descriptor. The checkWrite
method for class SecurityManager
always throws a SecurityException
.
public void checkWrite(String file)
SecurityException
if the calling thread is not allowed to write to the file specified by the string argument. The checkWrite
method for class SecurityManager
always throws a SecurityException
.
public void checkDelete(String file)
SecurityException
if the calling thread is not allowed to delete the specified file. This method is invoked for the current security manager by the delete
method of class File
.
The checkDelete
method for class SecurityManager
always throws a SecurityException
.
public void checkConnect(String host, int port)
SecurityException
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.
The checkConnect
method for class SecurityManager
always throws a SecurityException
.
host
and port
. public void checkConnect(String host, int port, Object context)
SecurityException
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.
The checkConnect
method for class SecurityManager
always throws a SecurityException
.
host
and port
. public void checkListen(int port)
SecurityException
if the calling thread is not allowed to wait for a connection request on the specified local port number. The checkListen
method for class SecurityManager
always throws a SecurityException
.
public void checkAccept(String host, int port)
SecurityException
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 the accept
method of class ServerSocket
.
The checkAccept
method for class SecurityManager
always throws a SecurityException
.
public void checkMulticast(InetAddress maddr)
public void checkMulticast(InetAddress maddr, byte ttl)
public void checkPropertiesAccess()
SecurityException
if the calling thread is not allowed to access or modify the system properties. This method is used by the getProperties
and setProperties
methods of class System
.
The checkPropertiesAccess
method for class SecurityManager
always throws a SecurityException
.
public void checkPropertyAccess(String key)
SecurityException
if the calling thread is not allowed to access the system property with the specified key
name. This method is used by the getProperty
method of class System
.
The checkPropertiesAccess
method for class SecurityManager
always throws a SecurityException
.
public boolean checkTopLevelWindow(Object window)
false
if the calling thread is not trusted to bring up the top-level window indicated by the window
argument. In this case, the caller can still decide to show the window, but the window should include some sort of visual warning. If the method returns true
, then the window can be shown without any special restrictions. See class Window
for more information on trusted and untrusted windows.
The checkSetFactory
method for class SecurityManager
always returns false
.
true
if the caller is trusted to put up top-level windows; false
otherwise. public void checkPrintJobAccess()
public void checkSystemClipboardAccess()
public void checkAwtEventQueueAccess()
public void checkPackageAccess(String pkg)
SecurityException
if the calling thread is not allowed to access the package specified by the argument. This method is used by the loadClass
method of class loaders.
The checkPackageAccess
method for class SecurityManager
always throws a SecurityException
.
public void checkPackageDefinition(String pkg)
SecurityException
if the calling thread is not allowed to define classes in the package specified by the argument. This method is used by the loadClass
method of some class loaders.
The checkPackageDefinition
method for class SecurityManager
always throws a SecurityException
.
public void checkSetFactory()
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
. The checkSetFactory
method for class SecurityManager
always throws a SecurityException
.
public void checkMemberAccess(Class clazz, int which)
public void checkSecurityAccess(String action)
public ThreadGroup getThreadGroup()
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