JSP/Servlet

1. JSP Mdel 1


浏览器 <------> JSP/Servlet <------>数据库

2. JSP Model 2


浏览器 <------> 控制器 <---->J模型(avaBean) <------> 数据库
                 ^
                 |
                 |
                视图

3. Tomcat 数据库连接池

在TOMCAT中，数据库连接池负责分配，管理和释放数据库连接，它允许重复使用一个现有的数据库连接，而不是重新建立连接

3. 数据库连接池应用

import java.sql.Connection
import java.sql.PreparedStatement
import java.sql.Resultset

javax.naming.Content ctx = new javax.naming.InitialContentx();
javax.sql.datasource ds = (javax.sql.datasource) ctx.lookup(dataource);
Connection con = ds.getConnection()

PreparedStatement pstmt = conns.prepareStatement("select * from table")

Resultset rs = psmt.executeQuery();

4. Sevlet

extend HttpServlet

doGet,doPost

service方法，再决定调用doGet or doPost

init() , destroy()

5.

HttpServletResponse,
setStatus
sendRedirect
sendError

addHeader("field","value)
setHeader("field","value)

setContextType
setCharacterEncoding

HttpServeletRequest

getRequestURI,getPathInfo,getQueryString,getRequestURL
getSession()
getSession(boolean create)

HttpSession
isNew,isvalidate,getAttribute,setAttribute



5. 使用Requestdispatcher包含web资源

getServletContext().getRequestDispatcher("");

6. 解决乱码问题

response.setContentType("text/html;Charset=utf-8")
PrintWriter out = response.getWrite()

output.println("new String(s.getBytes("utf-8","iso-8859-1"))

chinesestr = new String(chineseUTF8.getBytes(iso-8859-1"),utf-8);

7. JSP 表达式语言(EL)

${表达式}

8. JSP指令

page 页面指令包含下列

language,import,session,buffer,autoflush。。。

include 指令

9. JSP内置对象

out,request,response,session,page,exception,config,application

PageContext.getException
............getpage
............getRequest
............getResponse
............getSession
............getServletConfig
............getServletContext


10. JSP标签

<jsp:include>
<jsp:forward>
<jsp:param>
<jsp:useBean>
<jsp:setProperty>
<jsp:getProperty>

11 JSTL

<C:OUT>
<C:SET>
<C:IF>
<C:CHOOSE>
<C:WHEN>
<C:OTHERWISE>
<C:FOREACH>