刚学Servlet和MySql,以下是程序代码.为什么注释部分不能执行(不加注释可以).请大家帮忙看看哪里出了问题了.谢谢~
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.sql.*;public class CreateDB extends HttpServlet
{
private String url;
private String user;
private String password;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.sql.*;public class CreateDB extends HttpServlet
{
private String url;
private String user;
private String password;
public void init() throws ServletException
{
String driverClass = getInitParameter("driverClass");
url = getInitParameter("url");
user = getInitParameter("user");
password = getInitParameter("password");
try
{
Class.forName(driverClass);
}
catch (ClassNotFoundException ce)
{
throw new UnavailableException("加载数据库失败");
}
}
public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException
{
Connection conn = null;
Statement stmt = null;
try
{
conn = DriverManager.getConnection(url,user,password);
stmt = conn.createStatement();
//stmt.executeUpdate("create database bookstore");
//stmt.executeUpdate("use bookstore");
//stmt.executeUpdate("create table bookinfo(id INT)");
//stmt.addBatch("insert into bookinfo values(1)");
//stmt.executeBatch();
PrintWriter out = res.getWriter();
out.println("sucess");
out.close();
}
catch (SQLException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.sql.*;public class CreateDB extends HttpServlet
{
private String url;
private String user;
private String password;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.sql.*;public class CreateDB extends HttpServlet
{
private String url;
private String user;
private String password;
public void init() throws ServletException
{
String driverClass = getInitParameter("driverClass");
url = getInitParameter("url");
user = getInitParameter("user");
password = getInitParameter("password");
try
{
Class.forName(driverClass);
}
catch (ClassNotFoundException ce)
{
throw new UnavailableException("加载数据库失败");
}
}
public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException
{
Connection conn = null;
Statement stmt = null;
try
{
conn = DriverManager.getConnection(url,user,password);
stmt = conn.createStatement();
//stmt.executeUpdate("create database bookstore");
//stmt.executeUpdate("use bookstore");
//stmt.executeUpdate("create table bookinfo(id INT)");
//stmt.addBatch("insert into bookinfo values(1)");
//stmt.executeBatch();
PrintWriter out = res.getWriter();
out.println("sucess");
out.close();
}
catch (SQLException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
conn = DriverManager.getConnection(url,user,password);
System.out.println("conn="+conn); // 看看是否等于null;
stmt = conn.createStatement();
System.out.println("stmt ="+stmt ); // 看看是否等于null;2 确认你的username 有权限创建数据库!?
import java.sql.Connection;
import java.sql.DriverManager;public class Conn {
public static Connection getConn() {
Connection conn = null;
String driver = "com.mysql.jdbc.Driver";
String sourse = "jdbc:mysql://127.0.0.1:3306/mysql?characterEncoding=utf-8";
try {
Class.forName(driver);
conn = DriverManager.getConnection(sourse, "root", "12345678");
} catch (Exception e) {
System.out.println(e.toString());
}
return conn;
}public static void main(String[] args) {
System.out.println("Hello!" + Conn.getConn());
}
}
返回的值是Hello!com.mysql.jdbc.Connection@e24e2a.想问下这个是不是说明能连接上了.