1、在servlet中处理读取数据库中的内容；

2、编写一个java类封装对数据库的加载、连接以及各种查询、更新方法；

3、编写一个javaBean 其参数对应于数据库中的列名

4、servlet中读取数据完成后，交于jsp界面输出

数据库中的数据：

读取的数据：

具体如下：

一：java类，封装对数据库的加载、连接以及各种查询、更新方法；

package Tools;

import java.io.InputStream;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.Properties;

public class Tools {

private static String driver = null;

private static String url = null;

private static String password = null;

private static String user = null;

private Connection con=null;

private Statement state=null;

private PreparedStatement prestate=null;

private ResultSet rs=null;

//加载驱动

static{

try {

driver="com.microsoft.sqlserver.jdbc.SQLServerDriver";

url="jdbc:sqlserver://127.0.0.1:1433;DatabaseName=book";

password="123456";

user="sa";

Class.forName(driver).newInstance();

} catch (Exception e) {

e.printStackTrace();

}

}

//创建连接

public static Connection getConnection(){

try {

return DriverManager.getConnection(url, user, password);

} catch (SQLException e) {

e.printStackTrace();

return null;

}

}

//返回查询结果

public ResultSet getExecuteQuery(String sql) throws SQLException

{

con = Tools.getConnection();

state = con.createStatement();

rs = state.executeQuery(sql);

return rs;

}

//返回执行(update delete add)

public int getExecuteUpdate(String sql) throws SQLException

{

con = Tools.getConnection();

state = con.createStatement();

int num = state.executeUpdate(sql);

return num;

}

//释放资源

public static void release(ResultSet rs,Statement sm, Connection con){

if (rs!=null) {

try {

rs.close();

} catch (SQLException e) {

e.printStackTrace();

}

rs=null;

}

if (sm!=null) {

try {

sm.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

if (con!=null) {

try {

con.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

public void release(){

if (rs!=null) {

try {

rs.close();

} catch (SQLException e) {

e.printStackTrace();

}

rs=null;

}

if (state!=null) {

try {

state.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

if (con!=null) {

try {

con.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

public static void release(ResultSet rs,PreparedStatement psm, Connection con){

if (rs!=null) {

try {

rs.close();

} catch (SQLException e) {

e.printStackTrace();

}

rs=null;

}

if (psm!=null) {

try {

psm.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

if (con!=null) {

try {

con.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

}

二：javaBean 其参数对应于数据库中的列名package beans;

public class bookbean {

private int id;

private String name;

private float price;

private String author;

private int bookCount;

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public float getPrice() {

return price;

}

public void setPrice(float price) {

this.price = price;

}

public String getAuthor() {

return author;

}

public void setAuthor(String author) {

this.author = author;

}

public int getBookCount() {

return bookCount;

}

public void setBookCount(int bookCount) {

this.bookCount = bookCount;

}

}

三：开始的一个jsp界面，只有一个功能，实现跳转到servlet处理数据

pageEncoding="UTF-8"%>

主界面

RequestDispatcher rd =request.getRequestDispatcher("Page_go"); //跳转页面

rd.forward(request, response);

%>

四：servlet ，给出处理数据的代码

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

// TODO Auto-generated method stub

List list= GetData("select * from bookStore");

request.setAttribute("list", list);

request.getRequestDispatcher("jdbc.jsp").forward(request, response);;

}

/**

* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)

*/

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

// TODO Auto-generated method stub

doGet(request, response);

}

private List GetData(String sql)

{

List list = new ArrayList();

Tools t = new Tools();

try

{

ResultSet rs = t.getExecuteQuery(sql);

while(rs.next())

{

bookbean l = new bookbean();

l.setId(rs.getInt("id"));

l.setAuthor(rs.getString("author"));

l.setBookCount(rs.getInt("bookCount"));

l.setName(rs.getString("name"));

l.setPrice(rs.getFloat("price"));

list.add(l);

}

t.release();

return list;

}catch(Exception e)

{

t.release();

e.printStackTrace();

return null;

}

}

五：最后的输出jsp界面

pageEncoding="UTF-8"%>

Insert title here

cellspacing="1" bgcolor="#666666">

图书名称价格数量作者修改数量删除

//获取图书集合

List list= (List)request.getAttribute("list");

//判断集合是否有效

if(list==null || list.size()<1){

out.print("

没有任何图书信息！");

}

else {

for(bookbean b:list){

%>

}

}

%>