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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
checkXXX 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 subprocss.
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 subprocss.
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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