What Jsp/servlet should learn

Overview

The DRP has a long learning front because it stops learning from Java by learning. NET Halfway. Stop Java, learn. NET, make. NET knowledge more solid, and let me continue to learn the DRP, learning goals become more clear.

What should Jsp/servlet learn? IDE for Java

工欲善其事 its prerequisite, want to write a Jsp/servlet small demo, the first problem is to learn how to use the IDE, including the introduction of third-party jar package, third-party jar and source code, the integration of Tomcat, the deployment of Web programs, etc. This piece of content does not have much to do with the knowledge that we learn specific jsp/servlet, but, however, is a stumbling block that must be solved.

       Jsp/servlet

this piece of content is the focus, need to learn JSP built-in 9 objects, here we do not need to master all the objects, because the pure JSP development model is now basically eliminated.

Need to understand the JSP and servlet relationship, that is, after the servlet, why the introduction of a JSP? Here the main basis of the idea is divided, the multi-functional combination of things, divided into two things, servlet writing template is more troublesome, so there are JSP

Model1 and Model2 problems. The Model2 pattern is to request access to the Servlet,servlet call Business class processing, the business class calls the persisted class for processing, and then the servlet will put the corresponding content, this set of development patterns, which is also what Sun introduced JSP wants, however, Unexpectedly, the function of the JSP is too powerful, strong enough to be able to not write alone Servelt class can do everything, that is, Model1 mode is, request to jsp,jsp request Business processing class, business processing class request persisted class, and then JSP in the display content. Model1 the advantages of a simple development model, the shortcomings of the content of miscellaneous, the latter is not good maintenance; The disadvantage of MODEL2 is that the development model is more complex, but this shortcoming has made his advantage, that is, simple, more classes, simple, simple, it is very easy to maintain.

Jstl's knowledge. Why is the introduction of JSTL,JSTL is a new content, he put the previous JSP syntax format, almost all to replace the label format, what is the purpose of this? First: Weaken the function of JSP, second: Convenient art to do the corresponding beautification work.

The knowledge of filter and listener. Filter and listener are an embodiment of the idea of AOP. NET mvc3.0 also introduced a similar function, but. NET filter is a collection of Java filter and listener functions, Java filter is mainly to intercept the post request, that is, before the background code to run before the operation, listener mainly access method The operation.

JDBC

J DBC is the base of database persistence, which is the lowest class library of operating database in programming, Sun provides a set of interfaces for JDBC, and the specific database service providers implement specific functions according to these rules, then provide to the developers. This piece of content can be divided into 3 pieces of content to learn: JDBC specific interface function learning; database connection pool; dynamic proxy. Here is the database connection pool, a lot of third-party generation provides a third-party database connection pool, such as: Tomcat generation is implemented on Tomcat, if we want to use the Tomcat connection object, we need to call Tomcat to give me the class to do the corresponding Connection object acquisition, We can also create our own connection pool on the DAO layer itself, to manage its own connection objects.

Summary

Jsp/servlet a lot of knowledge needs to summarize, if in learning this piece of knowledge, did not learn, then in the back of the study of SSH, the difficulties will be greater, so, in this content of the study, to study hard.

What Jsp/servlet should learn