dbconnection.java

SQL工具,用SERVLET查看数据库中的内容,第一次编写.

package Bean;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

public class dbConnection 
{
	Connection conn;
	Statement stmt;
	ResultSet rs;
	String error=null;
   public dbConnection()
   {
	   try {
		Class.forName("com.mysql.jdbc.Driver");
		System.out.println("加载成功!");
	       } catch (Exception e) {
		System.out.println("加载不成功！");
		error=e.toString();
		e.printStackTrace();
	       }	
	     
   }
   public void getConnect(String dataBase,String user,String psw)
   {
	   try {
		conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/"+dataBase+"?user="+user+"&password="+psw+"&useUnicode=true&characterEncoding=gbk");
	    System.out.println("连接成功!");
	    
	   } catch (SQLException e) {
		error=e.toString();
		System.out.println("连接不成功！");
		e.printStackTrace();
	}  
   }
   public ResultSet selectSql(String sql)
   {
	   
	try {
		stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
	    rs=stmt.executeQuery(sql);
	    System.out.println("查询成功!");
	  } 
	catch (SQLException e) {
		error=e.toString();
		e.printStackTrace();
		System.out.println("查询不成功!");
	}
	return rs; 
   }
   public boolean deleteSql(String sql)
   {
	   int rss = 0;
	   try{
	  stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
	   rss=stmt.executeUpdate(sql);
	   }
	   catch(SQLException e)
	   {
		   error=e.toString();
		   e.printStackTrace();
	   }
	   if(rss==0)
		   return false;
	   else
		   return true;
		   
   }
   public void close()
   {
	   if(conn!=null)
	   {
		   try {
			conn.close();
		} 
		   catch (SQLException e) {
			   error=e.toString();
			   System.out.println("不能退出连接！");
			e.printStackTrace();
		}
	   }
   }
public String message() {
	return error;
}

}