Reading Notes for Chapter 5, Head First Servlets and JSP

147	Being a Web App	173	Writing the servlet class	200	Protext session attributes by synchronizing on the HttpSession
148	Objectives	174	Writing the Deployment Descriptor	201	The evils of SingleThreadModel
149	Kim wants to configure his email address in the DD, not hard-code it	175	There are no Dumb Questions	202	Only RequestAttributes and local variables are thread-safe!
150	Init Parameters to the rescue	176	Compile and deploy	203	Request attributes and Request dispatching
151	You can't use servlet init parameters until the servlet is initialized	177	Try it out; Troubleshooting	204	RequestDispatcher revealed
152	The servlet init parameters are read only ONCE---when the container initializes the servlet	178	The full story... (app initialization to servlet runs)	205	What's wrong with this code?
153	There are no dumb questions	179	The story continues...	206	Remembering the Listeners (answers to p. 184)
154	Testing your ServletConfig	180	Listeners: not just for context events	207	Attribute Scope (answers to p. 188)
155	How can a JSP get servlet init parameters	181	Pick the Listener	208	Code Magnets (answers to p. 161a)
156	Setting a request attribute works... but only for the JSP to which you forwarded the request	182	The eight listeners	209	Coffee Cram: Mock Exam Chapter 5 (Q1-Q2)
157	Context init parameters to the rescue	183	The HttpSessionBindingListner	210	Coffee Cram: Mock Exam Chapter 5 (Q3-Q5)
158	Remember the difference between servlet init parameters and context init parameters	184	Remembering the Listeners	211	Coffee Cram: Mock Exam Chapter 5 (Q6-Q7)
159	ServletConfig is one per servlet; ServletContext is one per web app	185	What, exactly is an attribute?	212	Coffee Cram: Mock Exam Chapter 5 (Q8-Q9)
160	There are no Dumb Questions	186	Attributes are not parameters!	213	Coffee Cram: Mock Exam Chapter 5 (Q10-Q12)
161a	Code Magnets (DD for getServletContext().getInitParameter("foo");)	187	The Three Scopes: Context, Request, and Session	214	Coffee Cram: Mock Exam Chapter 5 (Q13-Q14)
161b	If you see "init parameter" without servlet or context, assume servlet	188	Attribute Scope	215	Coffee Cram: Mock Exam Chapter 5 (Q1-Q2 answers)
162	So what else can you do with your ServletContext?	189	Attribute API	216	Coffee Cram: Mock Exam Chapter 5 (Q3-Q5 answers)
163	You can get a ServletContext in two different ways	190	The dark side of attributes...	217	Coffee Cram: Mock Exam Chapter 5 (Q6-Q7 answers)
164	What if you want an app init parameter that's a database DataSource?	191a	But then something goes horribly wrong...	218	Coffee Cram: Mock Exam Chapter 5 (Q8-Q9 answers)
165	What she really wants is a listener.	191b	Flex Your Mind (what caused the bug in Kim's code?)	219	Coffee Cram: Mock Exam Chapter 5 (Q10-Q12 answers)
166	She wants a ServletContextListener	192	Context scope isn't thread-safe!	220	Coffee Cram: Mock Exam Chapter 5 (Q13-Q14 answers)
167	Flex Your Mind (mechanism for making listener part of specific web app?)	193	The problem in slow motion...
168	Tutorial: a simple ServletContextListener	194	How do we make context attributes thread safe?
169	Making and using a context listener	195	Synchronizing the service method is a spectacularly BAD idea
170	We need three classes and one DD	196	Synchronizing the service method won't protect a context attribute
171	Writing the listener class	197	You don't need a lock on the servlet... you need the lock on the context!
172	Writing the attribute class (Dog)	198	Are Session attributes thread-safe?
173	Writing the servlet class	199	What's REALLY true about attributes and thread-safety?

p147 Being a Web App

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p148 Objectives

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p149 Kim wants to configure his email address in the DD, not hard-code it

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p150 Init Parameters to the rescue

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p151 You can't use servlet init parameters until the servlet is initialized

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p152 The servlet init parameters are read only ONCE---when the container initializes the servlet

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p153 There are no dumb questions

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p154 Testing your ServletConfig

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p155 How can a JSP get servlet init parameters

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p156 Setting a request attribute works... but only for the JSP to which you forwarded the request

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p157 Context init parameters to the rescue

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p158 Remember the difference between servlet init parameters and context init parameters

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p159 ServletConfig is one per servlet; ServletContext is one per web app

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p160 There are no Dumb Questions

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p161a Code Magnets (DD for getServletContext().getInitParameter("foo");)

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p161b If you see "init parameter" without servlet or context, assume servlet

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p162 So what else can you do with your ServletContext?

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p163 You can get a ServletContext in two different ways

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p164 What if you want an app init parameter that's a database DataSource?

@@@

p165 What she really wants is a listener.

@@@

p166 She wants a ServletContextListener

@@@

p167 Flex Your Mind (mechanism for making listener part of specific web app?)

@@@

p168 Tutorial: a simple ServletContextListener

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p169 Making and using a context listener

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p170 We need three classes and one DD

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p171 Writing the listener class

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p172 Writing the attribute class (Dog)

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p173 Writing the servlet class

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p174 Writing the Deployment Descriptor

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p175 There are no Dumb Questions

@@@

p176 Compile and deploy

@@@

p177 Try it out; Troubleshooting

@@@

p178 The full story... (app initialization to servlet runs)

@@@

p179 The story continues...

@@@

p180 Listeners: not just for context events

@@@

p181 Pick the Listener

@@@

p182 The eight listeners

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p183 The HttpSessionBindingListner

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p184 Remembering the Listeners

@@@

p185 What, exactly is an attribute?

@@@

p186 Attributes are not parameters!

@@@

p187 The Three Scopes: Context, Request, and Session

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p188 Attribute Scope

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p189 Attribute API

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p190 The dark side of attributes...

@@@

p191a But then something goes horribly wrong...

@@@

p191b Flex Your Mind (what caused the bug in Kim's code?)

@@@

p192 Context scope isn't thread-safe!

@@@

p193 The problem in slow motion...

@@@

p194 How do we make context attributes thread safe?

@@@

p195 Synchronizing the service method is a spectacularly BAD idea

@@@

p196 Synchronizing the service method won't protect a context attribute

@@@

p197 You don't need a lock on the servlet... you need the lock on the context!

@@@

p198 Are Session attributes thread-safe?

@@@

p199 What's REALLY true about attributes and thread-safety?

@@@

p200 Protext session attributes by synchronizing on the HttpSession

@@@

p201 The evils of SingleThreadModel

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p202 Only RequestAttributes and local variables are thread-safe!

@@@

p203 Request attributes and Request dispatching

@@@

p204 RequestDispatcher revealed

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p205 What's wrong with this code?

@@@

p206 Remembering the Listeners (answers to p. 184)

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p207 Attribute Scope (answers to p. 188)

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p208 Code Magnets (answers to p. 161a)

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p209 Coffee Cram: Mock Exam Chapter 5 (Q1-Q2)

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p210 Coffee Cram: Mock Exam Chapter 5 (Q3-Q5)

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p211 Coffee Cram: Mock Exam Chapter 5 (Q6-Q7)

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p212 Coffee Cram: Mock Exam Chapter 5 (Q8-Q9)

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p213 Coffee Cram: Mock Exam Chapter 5 (Q10-Q12)

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p214 Coffee Cram: Mock Exam Chapter 5 (Q13-Q14)

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p215 Coffee Cram: Mock Exam Chapter 5 (Q1-Q2 answers)

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p216 Coffee Cram: Mock Exam Chapter 5 (Q3-Q5 answers)

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p217 Coffee Cram: Mock Exam Chapter 5 (Q6-Q7 answers)

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p218 Coffee Cram: Mock Exam Chapter 5 (Q8-Q9 answers)

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p219 Coffee Cram: Mock Exam Chapter 5 (Q10-Q12 answers)

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p220 Coffee Cram: Mock Exam Chapter 5 (Q13-Q14 answers)

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End of CISC474 reading notes for HFSJ, Chapter 5