用的是mysql5.0.85,在csdn上下的mysql-connector-java-5.0.5-bin.jar,建立jsp文件,其中连接的代码是:
<%@ page contentType="text/html;charset=gb2312" %>
<%@ page language="java" %>
<%@ page import="com.mysql.jdbc.*" %>
<%@ page import="java.sql.*" %>
<%
String driverName="com.mysql.jdbc.Driver";
String userName="root";
String userPwd="root";
String dbName="test";
String tableName="goods";
String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPwd;
Class.forName("com.mysql.jdbc.Driver").newInstance();
java.sql.Connection conn=DriverManager.getConnection(url);
out.print("数据库连接成功");
%>
报错为:
org.apache.jasper.JasperException: Exception in JSP: /MySQLTest.jsp:129: String dbName="test";
10: String tableName="goods";
11: String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPwd;
12: Class.forName("com.mysql.jdbc.Driver").newInstance();
13: java.sql.Connection conn=DriverManager.getConnection(url);
14: out.print("数据库连接成功");
15: %>
是版本不对吗?是的话对应的jdbc从哪下呢?谢谢了。
<%@ page contentType="text/html;charset=gb2312" %>
<%@ page language="java" %>
<%@ page import="com.mysql.jdbc.*" %>
<%@ page import="java.sql.*" %>
<%
String driverName="com.mysql.jdbc.Driver";
String userName="root";
String userPwd="root";
String dbName="test";
String tableName="goods";
String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPwd;
Class.forName("com.mysql.jdbc.Driver").newInstance();
java.sql.Connection conn=DriverManager.getConnection(url);
out.print("数据库连接成功");
%>
报错为:
org.apache.jasper.JasperException: Exception in JSP: /MySQLTest.jsp:129: String dbName="test";
10: String tableName="goods";
11: String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPwd;
12: Class.forName("com.mysql.jdbc.Driver").newInstance();
13: java.sql.Connection conn=DriverManager.getConnection(url);
14: out.print("数据库连接成功");
15: %>
是版本不对吗?是的话对应的jdbc从哪下呢?谢谢了。
不用调用newInstance();都可以把。
这是csdn上的下载地址
http://download.csdn.net/source/980055
public class TestJDbC {
public static void main(String[] args){
ResultSet rs=null;
Statement stmt=null;
Connection conn=null;
try{
Class.forName("加载驱动");//方法1
//方法2直接 new 驱动();
conn=DriverManager.getConnection("url", "user", "password");
stmt=conn.createStatement();
rs=stmt.executeQuery("select *form student");
while(rs.next()){
System.out.println(rs.getString("字段"));
System.out.println(rs.getInt("字段"));
}
}catch(ClassNotFoundException e){
e.printStackTrace();
}catch(SQLException e1){
e1.printStackTrace();//SQL语句出现异常
}finally{
try{
if(rs!=null)
{
rs.close();
rs=null;
}
if(stmt!=null)
{
stmt.close();
stmt=null;
}
if(conn!=null)
{
conn.close();
conn=null;
}
}catch(SQLException e){
e.printStackTrace();//数据库关闭出现异常
}
}
}
}
既然报错报在了
Class.forName("com.mysql.jdbc.Driver").newInstance();这一行的话。应该是driver的问题,确定你的jar是正确的,而且已经放到了WEB-INF/lib下
//连接数据库类
public DbUtils() {
} private Connection conn = null;
ResultSet rs = null;
private String server = "127.0.0.1";
private String port = "3306";
private String db = "bean";
private String user = "root";
private String pass = "root";
private String drivername="com.mysql.jdbc.Driver";
private String URL="jdbc:mysql://"+server+":"+port+"/"+db+"?user="+user+"&password="+pass; public Connection getConn(){//get database connection
try{
Class.forName(drivername).newInstance();
conn = DriverManager.getConnection(URL);
}
catch(Exception e){
e.printStackTrace();
}
return this.conn ;
}
String url="jdbc:mysql://localhost:3306/"+dbName+"? user="+userName+"&password="+userPwd;
Class.forName("com.mysql.jdbc.Driver");就行了