What cannot be done using EJB?

Question

Hello,
My question is What cannot be done using EJB?

Answer 1

Enterprise Bean must not use read/write static fields. Using read-only static fields is allowed. Therefore, it is recommended that all static fields in enterprise bean class be declared as final.
Enterprise Bean must not use thread synchronization primitives to synchronize execution of multiple instances.
Enterprise bean must not attempt to manage threads. Enterprise bean must not attempt to start, stop, suspend, or resume a thread; or to change a thread's priority or name. The enterprise bean must not attempt to manage thread groups.
Enterprise Bean must not use the AWT functionality to attempt to output information to a display, or to input information from a keyboard.
Enterprise bean must not use java.io package to attempt to access files and directories in file system.
Enterprise bean must not attempt to directly read or write a file descriptor.
Enterprise bean must not attempt to listen on a socket, accept connections on a socket, or use a socket for multicast.
Enterprise bean must not attempt to set the socket factory used by ServerSocket, Socket, or the stream handler factory used by URL.
Enterprise bean must not attempt to query a class to obtain information about the declared members that are not otherwise accessible to the enterprise bean because of the security rules of the Java language. The enterprise bean must not attempt to use the Reflection API to access information that the security rules of the Java programming language make unavailable.
Enterprise bean must not attempt to create a class loader; obtain the current class loader; set the context class loader; set security manager; create a new security manager; stop the JVM; or change the input, output, and error streams.
Enterprise bean must not attempt to gain access to packages and classes that the usual rules of the Java programming language make unavailable to the enterprise bean.
Enterprise bean must not attempt to define a class in a package.
Enterprise bean must not attempt to use the subclass and object substitution features of the Java Serialization Protocol.
Enterprise bean must not attempt to obtain the security policy information for a particular code source.
Enterprise bean must not attempt to access or modify the security configuration objects (Policy, Security, Provider, Signer, and Identity).
Enterprise bean must not attempt to pass this as an argument or method result. The enterprise bean must pass the result of SessionContext.getEJBObject() or EntityContext. getEJBObject() instead.
Enterprise bean must not attempt to load a native library.
Rgds,
Seetesh