java 简单的jdbc连接数据库代码示例

约定不等于承诺〃 2022-08-20 04:15 242阅读 0赞

package cn.mxz.demo.dao;
    
    
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    
    import com.mysql.jdbc.Statement;
    
    public class DBConnection{
        /**驱动*/
        private static final String DRIVER = "oracle.jdbc.driver.OracleDriver";
        /**URL*/
        private static final String URL = "jdbc:oracle:thin:@10.10.244.124:1521:mete";
        /**用户名*/
        private static final String USER = "chawether";
        /**密码*/
        private static final String PASSWORD = "chawether";
        /**定义一个Connection 用来连接数据库*/  
        Connection conn;
        /**定义一个Statement用于向数据库发送要执行的SQL语句*/
        Statement stmt;
        /**定义一个结果集 用于存放查询结果*/
        ResultSet rs;
        /**定义一个结果集 用户存放插入数据库的条数*/
        int rows;
        
        /**
         * 打开数据库链接
         * @return
         */
        public Connection  getConnection() {
            try {
                Class.forName(DRIVER);
            } catch (ClassNotFoundException e) {
                System.out.println("找不到驱动程序类 ，加载驱动失败！");
            }
             try {
                 conn = DriverManager.getConnection(URL,USER,PASSWORD);
            } catch (SQLException se) {
                System.out.println("连接地址不正确！");
            }
             return conn;
        }
        
        /**
         * 执行查询语句
         * @param sql
         * @return
         * @throws SQLException 
         */
        public ResultSet query(String sql) throws SQLException {
             conn = this.getConnection();
             stmt= (Statement) conn.createStatement();
             rs = stmt.executeQuery(sql);
             return rs;
        }
        
        public int executeInsert(String sql) throws SQLException{
            conn = this.getConnection();
            stmt= (Statement) conn.createStatement();
            rows= stmt.executeUpdate(sql);
            return rows;
        }
        
        /**
         * 关闭数据库链接
         */
        public void close() {
            //关闭记录集
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException ex) {
                    ex.printStackTrace();
                }
            }
            //关闭声明 
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException ex) {
                    ex.printStackTrace();
                }
            }
            //关闭连接对象  
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException ex) {
                    ex.printStackTrace();
                }
            }
        }
    
    }