What is EJB, is it really that mysterious? ?
7. EJB learn and use, J2EE does not have to use EJB.
Through the explanation in the above section, it seems that EJB is not related to the system of B/S structure for developing Web applications, but it is not the case
. If we understand the "client program" as a certain server, this can also be applied, and
if the servers make EJB calls between each other, there is no problem of WAN bandwidth limitation.
However, try not to use EJB in the following situations:
1. For relatively simple pure Web application development, EJB is not required.
2. Applications that need to be used in conjunction with other service programs, but applications that call or return custom network protocols can be resolved
, do not need to use EJB.
3. Try not to use EJB for applications with C/S structure that are accessed concurrently by many people.
Summarize:
a. EJB implementation principle: It is to put the code originally implemented on the client side on the server side, and rely on RMI for communication.
b.RMI implementation principle : It is to realize distributed computing through the Java object serialization mechanism.
c. Server cluster: It is to connect servers of different functional modules through RMI communication to realize a complete function.