[整理]Java连接数据库的几种方法

最新推荐文章于 2025-02-19 21:59:28 发布

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#数据库 #java #sqlserver #string #import #jdbc

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本文介绍了三种不同的JDBC连接数据库的方法：硬编码连接字符串、通过属性文件读取配置信息及使用JNDI从容器中获取数据源。每种方法都提供了具体的实现步骤和示例代码。

JDBC硬编码连接

import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class JDBCConn { public static final String DRIVER = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; public static final String URL = "jdbc:sqlserver://localhost:1433;DatabaseName=books"; public static final String USER = "sa"; public static final String PWD = "ok"; private Connection conn = null; public Connection getConn() { try { Class.forName(DRIVER); conn = DriverManager.getConnection(URL,USER,PWD); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return conn; } }

读取propperties配置文件连接

1.创建读取配置文件的类

import java.io.IOException; import java.io.InputStream; import java.util.Properties; /** * 单列类：获取属性文件 * @author macau */ public class Env extends Properties { /** * 构造方法 */ private Env() { InputStream is = (InputStream) this.getClass().getResourceAsStream( "/db.properties");//创建输出流 try { load(is);//读取流 is.close(); } catch (IOException e) { e.printStackTrace(); } } private static Env instance;//当前类实例 /** * 获得当前实例 * @return */ public static Env getInstance() { if (instance == null) { makeInstance(); } return instance; } /** * 创建当前类实例 */ private static synchronized void makeInstance() { if (instance == null) { instance = new Env(); } } }

2.通过读取配置文件的类获取数据库连接参数

import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class PropConn { private String driver = Env.getInstance().getProperty("driver"); private String url = Env.getInstance().getProperty("url"); private String user = Env.getInstance().getProperty("user"); private String pwd = Env.getInstance().getProperty("pwd"); private Connection conn = null; public Connection getConn(){ try { Class.forName(driver); conn = DriverManager.getConnection(url,user,pwd); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return conn; } }

配置JNDI获取

1.在Tomcat安装目录的conf目录下的context.xml文件的<Context/>标记中添加配置

2.编码获取数据库连接

import java.sql.Connection; import java.sql.SQLException; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NamingException; import javax.sql.DataSource; public class JNDIConn { private Connection conn = null; public Connection getConn() { try { Context context = new InitialContext(); DataSource source = (DataSource) context .lookup("java:comp/env/jdbc/books"); conn = source.getConnection(); } catch (NamingException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } return conn; } }