java使用jdbc连接数据库步骤

// 1.加载驱动类,这里是用oracle数据库的驱动

Class.forName("oracle.jdbc.driver.OracleDriver");

// 2.获取连接

Connection    conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl", "账号", "密码");

// 3.创建statment（有sql注入的危险）或者preparestatment（预编译，没注入危险）

Statement      stmt = conn.createStatement();

// 4.执行sql取得结果executeQuery查询或者executeUpdate修改

ResultSet        rs = stmt.executeQuery("select * from emp ");

最后要关闭资源rs，stmt, conn

import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class JDBCTest {public static void main(String[] args) {Connection conn = null;Statement stmt = null;ResultSet rs = null;try {// 1.加载驱动类Class.forName("oracle.jdbc.driver.OracleDriver");// 2.获取连接conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl", "数据库账号", "密码");// 3.创建statment或者preparestatmentstmt = conn.createStatement();// 4.执行sql取得结果rs = stmt.executeQuery("select * from emp ");while (rs.next()) {String ename = rs.getString("ename");System.out.println(ename);}} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();} finally {// 5.关闭资源if (rs != null) {try {rs.close();} catch (SQLException e) {e.printStackTrace();}}if (stmt != null) {try {stmt.close();} catch (SQLException e) {e.printStackTrace();}}if (conn != null) {try {conn.close();} catch (SQLException e) {e.printStackTrace();}}}}}