练习&复习

一、Tomatcat数据源的配置

　　1,配置server.xml。

<Context path="/web" docBase="E:\webstudy" reloadable="true" debug="0">
                <Resource name="jdbc/study"
                    auth="Container"
                    type="javax.sql.DataSource"
                    maxActive="100"
                    maxIdle="30"
                    maxWait="10000"
                    username="root"
                    password="mysqladmin"
                    driverClassName="org.gjt.mm.mysql.Driver"
                    url="jdbc:mysql://localhost:3306/study_java"/>                    
            </Context>

　　2,配置项目目录下的web.xml

<resource-ref>
        <res-ref-name>jdbc/study</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>        
</resource-ref>

　　3,重启Tomcat服务器，编写测试练习

　　　　　a:编写Servlet。DataSourceTest.java

package org.xiong.tomcat.datasource;
import java.util.List;
import java.util.ArrayList;
import java.util.Date;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.xiong.demo.vo.BookInfo;

public class DataSourceTest extends HttpServlet
{
    public static  final String DATASOURCE_NAME="java:comp/env/jdbc/study";
    
    public void doGet(HttpServletRequest req,HttpServletResponse resp) throws ServletException,IOException
    {
        this.doPost(req,resp);
        
    }
    public void doPost(HttpServletRequest req,HttpServletResponse resp) throws ServletException,IOException
    {
        List<BookInfo> listBook=new ArrayList<BookInfo>();                
        Connection conn=null;
        PreparedStatement psmt=null;        
        String sql="select book_id,book_name,book_author,book_publishers,book_price,book_shelves_date from BookInfo";
        try
        {
            Context cxt=new InitialContext();
            DataSource ds=(DataSource)cxt.lookup(DATASOURCE_NAME);
            conn=ds.getConnection();        
            psmt=conn.prepareStatement(sql);
            ResultSet rst=psmt.executeQuery();
            while(rst.next())
            {
                BookInfo book=new BookInfo();
                book.setBook_id(rst.getInt(1));;
                book.setBook_name(rst.getString(2));
                book.setBook_author(rst.getString(3));
                book.setBook_publishers(rst.getString(4));
                book.setBook_price(rst.getFloat(5));
                book.setBook_shelves_date(new Date(rst.getDate(6).getTime()));
                listBook.add(book);        
            }
        }
        catch(Exception ex)
        {
            ex.printStackTrace();
        }
        finally
        {
            try
            {
                
                conn.close();
            }
            catch(Exception ex)
            {
                ex.printStackTrace();
            }
        }        
        req.setAttribute("list",listBook);
        req.getRequestDispatcher("DataSourceTest1.jsp").forward(req,resp);
    }
}

　　　　　b:编写输出页面

　

<%@ page contentType="text/html" pageEncoding="GBK"%>
<%@ page import="java.util.*"%>

<center>
    <table border="1" width="80%">
        <tr>
            <th>图书编号</th>
            <th>图书名称</th>
            <th>作&nbsp;&nbsp;&nbsp;&nbsp;者</th>
            <th>出&nbsp;版&nbsp;社</th>
            <th>定&nbsp;&nbsp;&nbsp;&nbsp;价</th>
            <th>上架日期</th>
        </tr>
<%
    List lst=(List)request.getAttribute("list");
    Iterator iter=lst.iterator();
while(iter.hasNext())
    {
        pageContext.setAttribute("book",iter.next());
%>
    <tr>
        <td>${book.book_id}</td>
        <td>${book.book_name}</td>
        <td>${book.book_author}</td>
        <td>${book.book_publishers}</td>
        <td>${book.book_price}</td>
        <td>${book.book_shelves_date}</td>
    </tr>
<%
    }
%>        
    </table>
</center>

　　　　   c:配置servlet

<servlet>
        <servlet-name>datasource</servlet-name>
        <servlet-class>org.xiong.tomcat.datasource.DataSourceTest</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>datasource</servlet-name>
        <url-pattern>/datasource_demo/DataSourceTest</url-pattern>        
    </servlet-mapping>

二，Filter练习，通过过滤器设置编码格式

　　1,编写setCharachterEncode.java

package org.xiong.demo.filtertest;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.Filter;
import javax.servlet.FilterConfig;
import javax.servlet.FilterChain;
import javax.servlet.http.HttpServlet;

public class SetCharacterEncode implements Filter
{
    private String str=null;
    public void init(FilterConfig filterConfig) throws ServletException
    {
            str=filterConfig.getInitParameter("ref");
    }
    public void doFilter(ServletRequest request,ServletResponse response,FilterChain chain) throws IOException,ServletException
    {
        request.setCharacterEncoding(str);
        chain.doFilter(request,response);
    }
    public void destroy()
    {
        
    }
}

　　2,配置Filter

<filter>
   <filter-name>SetEncoding</filter-name>
    <filter-class>org.xiong.demo.filtertest.SetCharacterEncode</filter-class>
   <init-param>
    <param-name>ref</param-name>
    <param-value>GBK</param-value>
   </init-param>
</filter>
<filter-mapping>
   <filter-name>SetEncoding</filter-name>
   <url-pattern>/bookdemo/*</url-pattern>
</filter-mapping>