数据库连接，通用增删改查

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

public class BaseDao {
    
        private static final String DRIVER="oracle.jdbc.driver.OracleDriver";
        private static final String URL="jdbc:oracle:thin://@localhost:1521:orcl";
        private static final String USER="scott";
        private static final String PASSWORD="root";
        /**
         * 结果集
         */
        protected ResultSet rs;
        /**
         * 预处理ＳＱＬ对象
         */
        protected PreparedStatement ps;
        /**
         * 连接对象
         */
        protected Connection conn;
        
        protected Connection getConn(){
                Connection conn=null;
                try {
                    Class.forName(DRIVER);
                     conn=DriverManager.getConnection(
                              URL,
                              USER,
                              PASSWORD);
                } catch (ClassNotFoundException | SQLException e) {
                    e.printStackTrace();
                }
                return conn;
            }
        
        /**
         * 
         * @param rs
         * @param ps
         * @param conn
         * 作者 :dis.jiang
         */
    protected void closeAll(){
        try {
            if(rs!=null){
                rs.close();
                rs=null;
            }
            if(ps!=null){
                ps.close();
                ps=null;
            }
            if(conn!=null){
                conn.close();
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
    //===========================通用的SQL操作==============================
    
    /**
     * 通用删除,修改,添加
     * @param sql
     * @param params
     * @return
     * 作者 :dis.jiang
     */
    public int execute(String sql,Object...params){
        int num=0;
        conn = getConn();
        try {
            ps=conn.prepareStatement(sql);
            for (int i = 0; i < params.length; i++) {
                ps.setObject(i+1, params[i]);
            }
            num= ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            closeAll();
        }
        return num;
    }
    
    /**
     * 通用查询
     * @param sql
     * @return
     * 作者 :dis.jiang
     */
    public ResultSet select(String sql,Object...params){
        conn = getConn();
        try {
            ps = conn.prepareStatement(sql);
            for (int i = 0; i < params.length; i++) {
                ps.setObject(i+1, params[i]);
            }
            rs=ps.executeQuery();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        return rs;
    }
    
}