| 订阅 | 在线投稿
分享
 
 
 

Jsp,JavaBean,Mysql的连接方法

来源:互联网  宽屏版  评论
2007-02-01 20:10:33

Jsp,JavaBean,Mysql的连接方法

利用JSP实现Web与数据库的连接:

(1).完成环境设置,导入java.sql包,命令如下:

import java.sql.*

(2).载入驱动器

(3).连接到数据库

(4).语句接口

(5).获得结果集

1. 测试环境:

windows 2003

j2sdk1.4.2_06

Tomcat 5.0

mysql-4.0.23-win

mm.mysql-2.0.4-bin.jar

2. 建立数据库及表

在Mysql中建个publish数据库,并建个book表。在book中添加id,title,price

3. JavaBean的代码: dbconn.java

package Border;

import java.sql.*; //完成环境设置,导入java.sql包

public class dbconn {

public dbconn()

{

}

//declare variable

private Connection conn = null;

private ResultSet rs = null;

private String server = "127.0.0.1"; // Can't use localhost , you must use IP or CNAME

private String port = "3306"; //change to your port

private String db = "publish"; //change to your db name

private String user = "root"; //change to your username

private String pass = "root"; //change to your password

private String drivername="org.gjt.mm.mysql.Driver"; //mysql driver

private String URL="jdbc:mysql://"+server+":"+port+"/"+db+"?useUnicode=true&characterEncoding=GBK&user="+user+"&password="+pass;

public Connection getConn(){ //get database connection

try{

Class.forName(drivername).newInstance(); //载入驱动器

conn = DriverManager.getConnection(URL); //连接到数据库

}

catch(Exception e){

e.printStackTrace();

}

return conn ;

}

public ResultSet executeSQL(String str) {

try{

Statement stmt = conn.createStatement(); //语句接口

rs = stmt.executeQuery(str); //获得结果集

}

catch(Exception e){

e.printStackTrace();

}

return rs;

}

}

编译javac dbconn.java,将编译后的文件dbconn.class放到目录 "你的项目"\WEB-INF\classes\Border\下

4. 调用Java Bean的JSP文件test.jsp

<%@ page contentType="text/html;charset=GBK" import="java.sql.*"%>

<jsp:useBean id="Border" scope="page" class="Border.dbconn" />

<%

ResultSet rs = null;

Connection conn = null;

conn = Border.getConn() ;

rs = Border.executeSQL("select * from book");

%>

<html>

<body>

<br>

<h2 align="center" > My first Jsp JavaBean Mysql </h2>

<br>

<table border="1" align="center">

<tr>

<th>

id

</th>

<th>

title

</th>

<th>

price

</th>

</tr>

<%

while(rs.next()) {

%>

<tr>

<th>

<%=rs.getString("id")%>

</th>

<th>

<%=rs.getString("title")%>

</th>

<th>

<%=rs.getString("price")%>

</th>

</tr>

<%}%>

<%

rs.close();

conn.close();

%>

</table>

<form name="form1" method="post" action="update.jsp">

<table width="210" border="1" align="center" cellpadding="0" cellspacing="0">

<tr>

<td width="77">title:</td>

<td width="127"><label>

<input name="Title" type="text" id="Title">

</label></td>

</tr>

<tr>

<td>price:</td>

<td><label>

<input name="Price" type="text" id="Price">

</label></td>

</tr>

<tr>

<td><div align="right">

<label>

<input type="submit" name="Submit" value="提交">

</label>

</div></td>

<td><label>

<input type="reset" name="Submit2" value="重置">

</label></td>

</tr>

</table>

</form>

</body>

</html>

5. update.jsp 写入数据库

<%@ page contentType="text/html;charset=GBK" import="java.sql.*"%>

<% request.setCharacterEncoding("GBK"); %>

<jsp:useBean id="Border" scope="page" class="Border.text" />

<%

Connection conn = null;

conn = Border.getConn() ;

String tit=request.getParameter("Title");

String prc=request.getParameter("Price");

Statement stmt = conn.createStatement();

stmt.executeUpdate("INSERT INTO book (title,price) VALUES ('"+tit+"','"+prc+"')");

%>

<jsp:forward page="text.jsp" />

6. 提供几个函数:

(1). getConnection

public static Connection getConnection(String url,

String user,

String password)

throws SQLException

Attempts to establish a connection to the given database URL. The DriverManager attempts to select an appropriate driver from the set of registered JDBC drivers.

Parameters:

url - a database url of the form jdbc:subprotocol:subname

user - the database user on whose behalf the connection is being made

password - the user's password

Returns:

a connection to the URL

Throws:

SQLException - if a database access error occurs

(2). createStatement

public Statement createStatement()

throws SQLException

Creates a Statement object for sending SQL statements to the database. SQL statements without parameters are normally executed using Statement objects. If the same SQL statement is executed many times, it may be more efficient to use a PreparedStatement object.

Result sets created using the returned Statement object will by default be type TYPE_FORWARD_ONLY and have a concurrency level of CONCUR_READ_ONLY.

Returns:

a new default Statement object

Throws:

SQLException - if a database access error occurs

(3). executeQuery

public ResultSet executeQuery(String sql)

throws SQLException

Executes the given SQL statement, which returns a single ResultSet object.

Parameters:

sql - an SQL statement to be sent to the database, typically a static SQL SELECT statement

Returns:

a ResultSet object that contains the data produced by the given query; never null

Throws:

SQLException - if a database access error occurs or the given SQL statement produces anything other than a single ResultSet object

(4). getString

public String getString(String columnName)

throws SQLException

Retrieves the value of the designated column in the current row of this ResultSet object as a String in the Java programming language.

Parameters:

columnName - the SQL name of the column

Returns:

the column value; if the value is SQL NULL, the value returned is null

Throws:

SQLException - if a database access error occurs

(5). next

public boolean next()

throws SQLException

Moves the cursor down one row from its current position. A ResultSet cursor is initially positioned before the first row; the first call to the method next makes the first row the current row; the second call makes the second row the current row, and so on.

If an input stream is open for the current row, a call to the method next will implicitly close it. A ResultSet object's warning chain is cleared when a new row is read.

Returns:

true if the new current row is valid; false if there are no more rows

Throws:

SQLException - if a database access error occurs

7. ok! Now game is over~~

8. 若您觉得满意,想转载或收藏这篇文章,我非常感谢,但请您注明作者: border ( border@hacker.cn )

http://blog.csdn.net/border1985

最后欢迎大家访问 --中国安全信息网-- http://www.hacker.cn/

Jsp,JavaBean,Mysql的连接方法 利用JSP实现Web与数据库的连接: (1).完成环境设置,导入java.sql包,命令如下: import java.sql.* (2).载入驱动器 (3).连接到数据库 (4).语句接口 (5).获得结果集 1. 测试环境: windows 2003 j2sdk1.4.2_06 Tomcat 5.0 mysql-4.0.23-win mm.mysql-2.0.4-bin.jar 2. 建立数据库及表 在Mysql中建个publish数据库,并建个book表。在book中添加id,title,price 3. JavaBean的代码: dbconn.java package Border; import java.sql.*; //完成环境设置,导入java.sql包 public class dbconn { public dbconn() { } //declare variable private Connection conn = null; private ResultSet rs = null; private String server = "127.0.0.1"; // Can't use localhost , you must use IP or CNAME private String port = "3306"; //change to your port private String db = "publish"; //change to your db name private String user = "root"; //change to your username private String pass = "root"; //change to your password private String drivername="org.gjt.mm.mysql.Driver"; //mysql driver private String URL="jdbc:mysql://"+server+":"+port+"/"+db+"?useUnicode=true&characterEncoding=GBK&user="+user+"&password="+pass; public Connection getConn(){ //get database connection try{ Class.forName(drivername).newInstance(); //载入驱动器 conn = DriverManager.getConnection(URL); //连接到数据库 } catch(Exception e){ e.printStackTrace(); } return conn ; } public ResultSet executeSQL(String str) { try{ Statement stmt = conn.createStatement(); //语句接口 rs = stmt.executeQuery(str); //获得结果集 } catch(Exception e){ e.printStackTrace(); } return rs; } } 编译javac dbconn.java,将编译后的文件dbconn.class放到目录 "你的项目"\WEB-INF\classes\Border\下 4. 调用Java Bean的JSP文件test.jsp <%@ page contentType="text/html;charset=GBK" import="java.sql.*"%> <jsp:useBean id="Border" scope="page" class="Border.dbconn" /> <% ResultSet rs = null; Connection conn = null; conn = Border.getConn() ; rs = Border.executeSQL("select * from book"); %> <html> <body> <br> <h2 align="center" > My first Jsp JavaBean Mysql </h2> <br> <table border="1" align="center"> <tr> <th> id </th> <th> title </th> <th> price </th> </tr> <% while(rs.next()) { %> <tr> <th> <%=rs.getString("id")%> </th> <th> <%=rs.getString("title")%> </th> <th> <%=rs.getString("price")%> </th> </tr> <%}%> <% rs.close(); conn.close(); %> </table> <form name="form1" method="post" action="update.jsp"> <table width="210" border="1" align="center" cellpadding="0" cellspacing="0"> <tr> <td width="77">title:</td> <td width="127"><label> <input name="Title" type="text" id="Title"> </label></td> </tr> <tr> <td>price:</td> <td><label> <input name="Price" type="text" id="Price"> </label></td> </tr> <tr> <td><div align="right"> <label> <input type="submit" name="Submit" value="提交"> </label> </div></td> <td><label> <input type="reset" name="Submit2" value="重置"> </label></td> </tr> </table> </form> </body> </html> 5. update.jsp 写入数据库 <%@ page contentType="text/html;charset=GBK" import="java.sql.*"%> <% request.setCharacterEncoding("GBK"); %> <jsp:useBean id="Border" scope="page" class="Border.text" /> <% Connection conn = null; conn = Border.getConn() ; String tit=request.getParameter("Title"); String prc=request.getParameter("Price"); Statement stmt = conn.createStatement(); stmt.executeUpdate("INSERT INTO book (title,price) VALUES ('"+tit+"','"+prc+"')"); %> <jsp:forward page="text.jsp" /> 6. 提供几个函数: (1). getConnection public static Connection getConnection(String url, String user, String password) throws SQLException Attempts to establish a connection to the given database URL. The DriverManager attempts to select an appropriate driver from the set of registered JDBC drivers. Parameters: url - a database url of the form jdbc:subprotocol:subname user - the database user on whose behalf the connection is being made password - the user's password Returns: a connection to the URL Throws: SQLException - if a database access error occurs (2). createStatement public Statement createStatement() throws SQLException Creates a Statement object for sending SQL statements to the database. SQL statements without parameters are normally executed using Statement objects. If the same SQL statement is executed many times, it may be more efficient to use a PreparedStatement object. Result sets created using the returned Statement object will by default be type TYPE_FORWARD_ONLY and have a concurrency level of CONCUR_READ_ONLY. Returns: a new default Statement object Throws: SQLException - if a database access error occurs (3). executeQuery public ResultSet executeQuery(String sql) throws SQLException Executes the given SQL statement, which returns a single ResultSet object. Parameters: sql - an SQL statement to be sent to the database, typically a static SQL SELECT statement Returns: a ResultSet object that contains the data produced by the given query; never null Throws: SQLException - if a database access error occurs or the given SQL statement produces anything other than a single ResultSet object (4). getString public String getString(String columnName) throws SQLException Retrieves the value of the designated column in the current row of this ResultSet object as a String in the Java programming language. Parameters: columnName - the SQL name of the column Returns: the column value; if the value is SQL NULL, the value returned is null Throws: SQLException - if a database access error occurs (5). next public boolean next() throws SQLException Moves the cursor down one row from its current position. A ResultSet cursor is initially positioned before the first row; the first call to the method next makes the first row the current row; the second call makes the second row the current row, and so on. If an input stream is open for the current row, a call to the method next will implicitly close it. A ResultSet object's warning chain is cleared when a new row is read. Returns: true if the new current row is valid; false if there are no more rows Throws: SQLException - if a database access error occurs 7. ok! Now game is over~~ 8. 若您觉得满意,想转载或收藏这篇文章,我非常感谢,但请您注明作者: border ( [url=mailto:border@hacker.cn]border@hacker.cn[/url] ) [url=http://blog.csdn.net/border1985]http://blog.csdn.net/border1985[/url] 最后欢迎大家访问 --中国安全信息网-- [url=http://www.hacker.cn/]http://www.hacker.cn/[/url]
󰈣󰈤
 
 
 
>>返回首页<<
 
 热帖排行
 
 
 
静静地坐在废墟上,四周的荒凉一望无际,忽然觉得,凄凉也很美
©2005- 王朝网络 版权所有