import java.net.*;
import java.sql.*;
import java.io.*;
import java.util.*;
import java.io.IOException;
import java.sql.SQLException;
public class MySQLJDBC
{
public static void main(String[] args) throws IOException, SQLException
{
try
{
mysql.con con1=new mysql.con();
Connection con=con1.getCon();
Statement stmt = con.createStatement();
String tableName = “student”;
String query = “select * from ” + tableName;
ResultSet rs = stmt.executeQuery(query);
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
while (rs.next())
{
System.out.print(rs.getString(”sno”)+” “);
System.out.print(rs.getString(”sname”)+” “);
System.out.print(rs.getString(”ssex”)+” “);
System.out.print(rs.getInt(”sage”)+” “);
System.out.println(rs.getString(”sdept”));
}
System.out.println(columnCount);
rs.close();
stmt.close();
con.close();
}
catch(SQLException ex)
{
System.out.println(”SQLException:”);
while (ex != null)
{
System.out.println(”SQLState: ” + ex.getSQLState());
System.out.println(”Message: ” + ex.getMessage());
System.out.println(”Vendor: ” + ex.getErrorCode());
ex = ex.getNextException();
System.out.println(”");
}
}
catch(Exception ex)
{}
}
}
优化了代码的简洁，分离了连接mysql的用户名和密码，为什么？
当然是为了安全性和不想没段代码都写上长长的数据连接……