第一种方式 直接获取驱动，地址，用户名，密码 并返回连接对象
package cn.tao.demo;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class JDBCUtils { private JDBCUtils(){} private static Connection con; static{ try { Class.forName("com.mysql.jdbc.Driver"); //2获得连接 对象 String url ="jdbc:mysql://localhost:3306/day37"; String username="root"; String password="root"; con = DriverManager.getConnection(url, username, password); } catch (Exception e) { throw new RuntimeException("数据库连接失败"); } } //定义静态方法 返回数据库的连接 public static Connection getConnection(){ return con; } //关资源 public static void close(Connection con, Statement stat){ if(stat!=null){ try { stat.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } if(con!=null){ try { con.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } public static void close(Connection con, Statement stat,ResultSet rs){ if(rs!=null){ try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } if(stat!=null){ try { stat.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } if(con!=null){ try { con.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } }}第二种方式 通过读取配置文件获得驱动，地址，用户，密码 定义方法返回连接对象
package cn.tao.demo;import java.io.InputStream;import java.sql.Connection;import java.sql.DriverManager;import java.util.Properties;public class JDBCUtilsConfig { private static Connection con; private static String driverClass; private static String url; private static String user; private static String password; static{ try { readConfig(); Class.forName(driverClass); con = DriverManager.getConnection(url, user, password); } catch (Exception e) { e.printStackTrace(); } } private static void readConfig() throws Exception{ InputStream in = JDBCUtilsConfig.class.getClassLoader().getResourceAsStream("database.properties"); Properties pro = new Properties(); pro.load(in); driverClass = pro.getProperty("driverClass"); url = pro.getProperty("url"); user = pro.getProperty("user"); password = pro.getProperty("password"); } public static Connection getConnection(){ return con; }}
第三种 连接池的方式
package cn.com.demo;import javax.sql.DataSource;import org.apache.commons.dbcp.BasicDataSource;public class JDBCUtils { private static BasicDataSource data = new BasicDataSource(); static{ data.setDriverClassName("com.mysql.jdbc.Driver"); data.setUrl("jdbc:mysql://localhost:3306/day37"); data.setUsername("root"); data.setPassword("root"); data.setInitialSize(20); data.setMaxActive(30); data.setMaxIdle(5); data.setMinIdle(1); } public static DataSource getDataSource(){ return data; }
转载于:https://www.cnblogs.com/foreverone/p/10449078.html
