Question

tomcat与mysql的连接

用jsp做得一个系统，可是tomcat启动后，用浏览器打开页面都正常，但是登陆用户后，页面跳转错误，数据库mysql连接不起来怎么弄啊？急用

Answer 1

首先你要有mysql-connector-java-5.1.0-bin.jar，将该文件放置在tomcat\webapps\ROOT\WEB-INF\lib目录下，确保你能正确登陆mysql,你可以直接打开mysql，先执行下你的查询语句，这里有个tomcat连接mysql的例子：

Class.forName("com.mysql.jdbc.Driver");
String dsn="jdbc:mysql://localhost:3306/test_db?user=root&password=sa";

Connection conn=DriverManager.getConnection(dsn);

Statement cmd=conn.createStatement();

//新增数据
String sql = "select max(id) as num from employee";
ResultSet numRs = cmd.executeQuery(sql);
numRs.next();

int id = numRs.getInt(1) + 1;

sql = "insert into employee(id,last_name,first_name,birth,sex,email) values(" + id + ",'cc,'dd','1982-11-16','M','abc@cc.com')";
cmd.executeUpdate(sql);

//查询数据
ResultSet rs=cmd.executeQuery("select * from employee");

while(rs.next())
{
out.println(rs.getString(1) + "--" + rs.getString(2) + "--" + rs.getString(3)+ "--" + rs.getString(4)+ "--" + rs.getString(5)+ "--" + rs.getString(6));
out.println("<br/>");

Class.forName("com.mysql.jdbc.Driver");
String dsn="jdbc:mysql://localhost:3306/test_db?user=root&password=sa";

Connection conn=DriverManager.getConnection(dsn);

Statement cmd=conn.createStatement();

//新增数据
String sql = "select max(id) as num from employee";
ResultSet numRs = cmd.executeQuery(sql);
numRs.next();

int id = numRs.getInt(1) + 1;

sql = "insert into employee(id,last_name,first_name,birth,sex,email) values(" + id + ",'cc,'dd','1982-11-16','M','abc@cc.com')";
cmd.executeUpdate(sql);

//查询数据
ResultSet rs=cmd.executeQuery("select * from employee");

while(rs.next())
{
out.println(rs.getString(1) + "--" + rs.getString(2) + "--" + rs.getString(3)+ "--" + rs.getString(4)+ "--" + rs.getString(5)+ "--" + rs.getString(6));
out.println("<br/>");
}
cmd.close();
rs.close();
conn.close();
}

需下载连接数据驱动mysql-connector-java-5.1.0-bin.jar，这个文件可到站点基地[zdbase.com]下载，下载后将mysql-connector-java-5.1.0-bin.jar放置tomcat\webapps\ROOT\WEB-INF\lib目录下即可

下载附件：mysql-connector-java-5.1.0-bin.jar

Answer 2

<%Class.forName("com.mysql.jdbc.Driver");
String url="jdbc:mysql://localhost:3306/mysql";
Connection conn=DriverManager.getConnection(url,"root","");
Statement stmt=conn.createStatement();
String sql="select * from customer";
ResultSet rs=stmt.executeQuery(sql);%>

驱动注册灯都要写好，这个是JDBC
还有在工程里面加上 mysql的驱动jar包