Head First Servlet and JSP笔记 - Ch3 MVC 实战

MVC实战

Can't just sit here and read all day

[ ] 1. set up development
[ ] 2. set up development following the servlet and jsp specs and Tomcat requirement
[ ] 3. Writing. Compiling. deploying and running

Web App Content

static content
JSP pages
Servlet classes
the deplyment descriptor
tag libraries
JAR files
Java class files

==V==

review the user's views

graph TD
    A[proj-BeerAdvisor] --> B(beerV1)
    B --> C1(web)
    B --> C2(etc)
    C1 --> |static content| C1A[form.html]
    C2 --> |the deplyment descriptor| C2A[web.xml]

form.html

<html>
    <body>
        <h1 align="center">Beer</h1>
        <form method="post" action="selectBeer.do">
            <p>select beer characteristics</p>
            color:
            <select name="color" size="1">
                <option value="light">light</option>
                <option value="amber">amber</option>
                <option value="brown">brown</option>
                <option value="dark">dark</option>
            </select>
            <br>
            <center>
                <input type="submit">
            </center>
        </form>
    </body>        
</html>

为什么是POST不是GET？

use the dd web.xml to map com.example.web.BeerSelect

mapping the logical name to a servlet class file P78

web.xml

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                      http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
  version="4.0"
  metadata-complete="true">

  <display-name>Welcome to Tomcat</display-name>
  <description>
     Welcome to Tomcat
  </description>
  <servlet>
    <servlet-name>Ch3 Beer</servlet-name>
    <servlet-class>com.example.web.BeerSelect</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>Ch3 Beer</servlet-name>
    <url-pattern>/SelectBeer.do</url-pattern>
  </servlet-mapping>
</web-app>

Deploying and test the opening page

graph TD
    A[tomcat] --> B(webapps)
    B --> C(beer)
    C --> |static content| D1[form.html]
    C --> D2(WEB-INF)
    D2 --> |the deplyment descriptor| E1[web.xml]

此处有测试

==C==

BeerSelect.java

package com.example.web;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

public class BeerSelect extends HttpServlet {
    public void doPost(HttpServletRequest request,
        HttpServletResponse response)
    throws IOException, ServletException{
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("Beer Selection Advice<br>");
        String c = request.getParameter("color");
        out.println("<br>Got beer color " + c);
    }
}

java的异常处理怎么长这样？

package 有点名字空间的意思。

import 和python很像，机制想来也不简单。

ContentType

API

graph TD
    A(javax.servlet.http.) --> B1(HttpServlet)
    A --> B2(HttpServletRequest)
    A --> B3(HttpServletResponse)
    B1 --> B1A(javax.servlet.GenericServlet)
    B1A --> C(javax.servlet.)
    B2 --> C
    B3 --> C
    C --> D1(Serverlet)
    C --> D2(ServletRequest)
    C --> D3(ServletResponse)

最后编辑于：2018.01.12 09:25:45