Servlet Basics
SERVLET BASICS
Topics in This Chapter • The basic structure of servlets • A simple servlet that generates plain text • A servlet that generates HTML • Servlets and packages • Some utilities that help build HTML • The servlet life cycle • How to deal with multithreading problems • Tools for interactively talking to servlets • Servlet debugging strategies Training courses from the book’s author: http://courses.coreservlets.com/
• • • • • Personally developed and taught by Marty Hall Available onsite at your organization (any country) Topics and pace can be customized for your developers Also available periodically at public venues Topics include Java programming, beginning/intermediate servlets and JSP, advanced servlets and JSP, Struts, JSF/MyFaces, Ajax, GWT, Ruby/Rails and more. Ask for custom courses!
© Prentice Hall and Sun Microsystems Press. Personal use only.
3
Training courses from the book’s author: http://courses.coreservlets.com/
• • • • • Personally developed and taught by Marty Hall Available onsite at your organization (any country) Topics and pace can be customized for your developers Also available periodically at public venues Topics include Java programming, beginning/intermediate servlets and JSP, advanced servlets and JSP, Struts, JSF/MyFaces, Ajax, GWT, Ruby/Rails and more. Ask for custom courses!
As discussed in Chapter 1, servlets are programs that run on a Web or application server and act as a middle layer between a request coming from a Web browser or other HTTP client and databases or applications on the HTTP server. Their job is to perform the following tasks, as illustrated in Figure 3–1. Database Legacy Application Java Application Web Service ...
JDBC JNI RMI SOAP ...
Client (End User)
Figure 3–1
Web Server (Servlets/JSP)
The role of Web middleware.
1. Read the explicit data sent by the client. The end user normally enters this data in an HTML form on a Web page. However, the data could also come from an
Topics in This Chapter • The basic structure of servlets • A simple servlet that generates plain text • A servlet that generates HTML • Servlets and packages • Some utilities that help build HTML • The servlet life cycle • How to deal with multithreading problems • Tools for interactively talking to servlets • Servlet debugging strategies Training courses from the book’s author: http://courses.coreservlets.com/
• • • • • Personally developed and taught by Marty Hall Available onsite at your organization (any country) Topics and pace can be customized for your developers Also available periodically at public venues Topics include Java programming, beginning/intermediate servlets and JSP, advanced servlets and JSP, Struts, JSF/MyFaces, Ajax, GWT, Ruby/Rails and more. Ask for custom courses!
© Prentice Hall and Sun Microsystems Press. Personal use only.
3
Training courses from the book’s author: http://courses.coreservlets.com/
• • • • • Personally developed and taught by Marty Hall Available onsite at your organization (any country) Topics and pace can be customized for your developers Also available periodically at public venues Topics include Java programming, beginning/intermediate servlets and JSP, advanced servlets and JSP, Struts, JSF/MyFaces, Ajax, GWT, Ruby/Rails and more. Ask for custom courses!
As discussed in Chapter 1, servlets are programs that run on a Web or application server and act as a middle layer between a request coming from a Web browser or other HTTP client and databases or applications on the HTTP server. Their job is to perform the following tasks, as illustrated in Figure 3–1. Database Legacy Application Java Application Web Service ...
JDBC JNI RMI SOAP ...
Client (End User)
Figure 3–1
Web Server (Servlets/JSP)
The role of Web middleware.
1. Read the explicit data sent by the client. The end user normally enters this data in an HTML form on a Web page. However, the data could also come from an