跪求?。?！JSP網(wǎng)上書店系統(tǒng)

很明顯啊，你的jstl的c標(biāo)簽引用的有問題。

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可能是jar包版本不同導(dǎo)致路徑不對。

某網(wǎng)上書城可以查詢、刪除書籍，現(xiàn)要求使用JSP實(shí)現(xiàn)該功能

簡單的增刪改查功能

package?EBookDao;

import?java.sql.Connection;

import?java.sql.PreparedStatement;

import?java.sql.ResultSet;

import?java.sql.SQLException;

import?java.util.ArrayList;

import?java.util.List;

import?DBUtil.DBUtil;

import?DBUtil.EBook;

/*

*查詢書集信息

*?

*?*/

public?class?EBookCZ?{

public?ListEBook?find()?{

Connection?conn?=?null;

PreparedStatement?ps?=?null;

ResultSet?rs?=?null;

ListEBook?list?=?new?ArrayListEBook();

try?{

conn?=?DBUtil.getConnection();

String?sql?=?"SELECT?*?FROM?ebook";

ps?=?conn.prepareStatement(sql);

rs?=?ps.executeQuery();

while?(rs.next())?{

EBook?eBook?=?new?EBook();

eBook.setId(rs.getInt("ID"));

eBook.setBname(rs.getString("bname"));

eBook.setPrice(rs.getString("price"));

list.add(eBook);

System.out.println(rs.getInt("ID")+rs.getString("bname")+rs.getString("price"));

}

}?catch?(SQLException?sqle)?{

sqle.printStackTrace();

}?finally?{

DBUtil.close(conn,?ps,?rs);

}

return?list;

}

/*

?*通過id刪除書集信息

?*?

?*?*/

public?static?EBook?DelById(int?id)?{

Connection?conn?=?null;

PreparedStatement?ps?=?null;

ResultSet?rs?=?null;

EBook?book?=?null;

try?{

conn?=?DBUtil.getConnection();

String?sql?=?"delete?ebook?";

sql?+=?"WHERE?ID=??";

ps?=?conn.prepareStatement(sql);

ps.setInt(1,?id);

rs?=?ps.executeQuery();

if?(rs.next())?{

book?=?new?EBook();

book.setId(rs.getInt("ID"));

book.setBname(rs.getString("bname"));

book.setPrice(rs.getString("price"));

}

}?catch?(SQLException?sqle)?{

sqle.printStackTrace();

}?finally?{

DBUtil.close(conn,?ps,?rs);

}

return?book;

}

}

package?EBookServlet;

import?java.io.IOException;

import?java.io.PrintWriter;

import?java.util.List;

import?javax.servlet.ServletException;

import?javax.servlet.http.HttpServlet;

import?javax.servlet.http.HttpServletRequest;

import?javax.servlet.http.HttpServletResponse;

import?DBUtil.EBook;

import?EBookDao.EBookCZ;

public?class?EBookServlet?extends?HttpServlet?{

/**

?*?

?*/

private?static?final?long?serialVersionUID?=?1L;

/**

?*?Constructor?of?the?object.

?*/

public?EBookServlet()?{

super();

}

/**

?*?Destruction?of?the?servlet.?br

?*/

public?void?destroy()?{

super.destroy();?//?Just?puts?"destroy"?string?in?log

//?Put?your?code?here

}

/**

?*?The?doGet?method?of?the?servlet.?br

?*?

?*?This?method?is?called?when?a?form?has?its?tag?value?method?equals?to?get.

?*?

?*?@param?request

?*????????????the?request?send?by?the?client?to?the?server

?*?@param?response

?*????????????the?response?send?by?the?server?to?the?client

?*?@throws?ServletException

?*?????????????if?an?error?occurred

?*?@throws?IOException

?*?????????????if?an?error?occurred

?*/

public?void?doGet(HttpServletRequest?request,?HttpServletResponse?response)

throws?ServletException,?IOException?{

this.doPost(request,?response);

}

/**

?*?The?doPost?method?of?the?servlet.?br

?*?

?*?This?method?is?called?when?a?form?has?its?tag?value?method?equals?to

?*?post.

?*?

?*?@param?request

?*????????????the?request?send?by?the?client?to?the?server

?*?@param?response

?*????????????the?response?send?by?the?server?to?the?client

?*?@throws?ServletException

?*?????????????if?an?error?occurred

?*?@throws?IOException

?*?????????????if?an?error?occurred

?*/

public?void?doPost(HttpServletRequest?request,?HttpServletResponse?response)

throws?ServletException,?IOException?{

response.setContentType("text/html;charset=utf-8");

PrintWriter?out?=?response.getWriter();

String?method?=?request.getParameter("method");

String?url?=?"";

EBookCZ?bookCZ=new?EBookCZ();

?if?(method?!=?null??method.equals("find"))?{

?System.out.println("find做完了");

??url?=?"EBookMNG.jsp";

??ListEBook?list?=?bookCZ.find();

??request.setAttribute("list",?list);

}?else?if?(method?!=?null??method.equals("findById"))?{

?System.out.println("findbyid做完了");

??url?=?"OK.jsp";

??int?id?=?Integer.parseInt(request.getParameter("id"));

??EBook?book?=?EBookCZ.DelById(id);

??request.setAttribute("book",?book);

}

request.getRequestDispatcher(url).forward(request,?response);

out.flush();

out.close();

}

/**

?*?Initialization?of?the?servlet.?br

?*?

?*?@throws?ServletException

?*?????????????if?an?error?occurs

?*/

public?void?init()?throws?ServletException?{

//?Put?your?code?here

}

}

javaweb書城項(xiàng)目 改別人項(xiàng)目遇到的問題

明顯是路徑?jīng)]找到，你調(diào)試下程序，在java代碼加下斷點(diǎn)，看看有沒有進(jìn)斷點(diǎn)。

網(wǎng)上書店連接SQL Server 2005的java代碼怎么寫？

連接數(shù)據(jù)庫的典型步驟

第一步：加載正確的數(shù)據(jù)庫驅(qū)動(dòng)程序

第二步，定義所要連接數(shù)據(jù)庫的地址

String ODBCURL＝“jdbc:odbc:dbName”;

String oracleURL= "jdbc:oracle:thin:@host:port:dbName“;

String mysqlURL= "jdbc:mysql:// host:port/dbName“;

String sqlURL＝“jdbc:microsoft:sqlserver://host:1433;DatabaseName=dbName”;

第三步，建立與數(shù)據(jù)庫的連接

DriverManager.getConnection(oracleURL,

username,

password);

第四步，創(chuàng)建語句對象

Statement statement = connection.createStatement();

第五步，聲明SQL語句，并將該語句通過Statement對象提交給服務(wù)器進(jìn)行執(zhí)行。

Stringsql= “SELECT * FROM ONTACT_TABLE”;

ResultSet resultSet=statement.executeQuery(sql);

該語句將sql命令提交給數(shù)據(jù)庫服務(wù)器進(jìn)行執(zhí)行，并將執(zhí)行結(jié)果存儲在ResultSet對象中進(jìn)行執(zhí)行。

Statement接口主要有如下三個(gè)方法：

1. ResultSet executeQuery(String sql)

用于執(zhí)行查詢語句，返回 ResultSet結(jié)果集（一個(gè)二維表）

2. int executeUpdate(String sql)

用于執(zhí)行添加、刪除或修改操作，返回被更新記錄的條數(shù)

3. boolean execute(String sql)

執(zhí)行參數(shù)部分的SQL語句；

當(dāng)SQL語句的執(zhí)行結(jié)果是一個(gè)ResultSet結(jié)果集時(shí)，本方法返回true；并可以通過Statement?getResultSet()方法得到返回的結(jié)果集

當(dāng)SQL語句執(zhí)行后沒有返回的結(jié)果集時(shí)，該方法返回false

第六步：對查詢結(jié)果進(jìn)行分析

while(resultSet.next()){

name =resultSet.getString(1);

phone =resultSet.getString(2);

System.out.println(name+","+phone);

}

第七步，關(guān)閉打開的資源

resultSet.close();

statement.close();

connection.close();

將打開的資源關(guān)閉。

注意：資源關(guān)閉的順序和打開的順序恰恰相反。