为什么我的java程序连不上数据库啊
我用的是mysqlimport java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class UserManager {
public User loginQuery(User user)
{ String sql = " select * from user where username=?";
User temp = null;
DBconn dbcon = new DBconn();
Connection conn = null;
conn = dbcon.getConnection();
PreparedStatement ps = null;
try {
ps = conn.prepareStatement(sql);
ps.setString(1,user.getUsername());
ResultSet rs = ps.executeQuery(sql);
if(rs.next()){
temp = new User();
temp.setPassword(rs.getString("username"));
temp.setPassword(rs.getString("password"));
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
conn.close(); } catch (Exception e) {
e.printStackTrace();
}
}
return temp;
}
}
请大家帮忙看看
mysqljava
我用的是mysqlimport java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class UserManager {
public User loginQuery(User user)
{ String sql = " select * from user where username=?";
User temp = null;
DBconn dbcon = new DBconn();
Connection conn = null;
conn = dbcon.getConnection();
PreparedStatement ps = null;
try {
ps = conn.prepareStatement(sql);
ps.setString(1,user.getUsername());
ResultSet rs = ps.executeQuery(sql);
if(rs.next()){
temp = new User();
temp.setPassword(rs.getString("username"));
temp.setPassword(rs.getString("password"));
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
conn.close(); } catch (Exception e) {
e.printStackTrace();
}
}
return temp;
}
}
请大家帮忙看看
mysqljava
import java.sql.DriverManager;public class DBconn {
private String name;
private String password;
private String url;
public DBconn(){
name="root";
password="99";
url="jdbc:mysql://localhost:3306/user";
}
public Connection getConnection()
{
Connection connection = null;
try {
Class.forName("com.mysql.jdbc.Driver");
connection = DriverManager.getConnection(url,name,password);
} catch (Exception e) {
System.out.print("++++++++++++");
} return connection;
}
}
大家帮忙看看
以前都是在搞javaweb
现在直接用java连 却连不上了
2个错误
1:桌面的java应用程序可能不支持问好sql语句改写为
String sql = "select * from user where username='"+user.getUsername()+"'";
2 驱动包有问题 重新配置了下
多谢各位了