[整理]Java連接數據庫的幾種方法

JDBC硬編碼連接

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; } }

 

讀取propperties配置文件連接

1.創建讀取配置文件的類

 import java.io.IOException; import java.io.InputStream; import java.util.Properties; /** * 單列類：獲取屬性文件 * @author macau */ public class Env extends Properties { /** * 構造方法 */ private Env() { InputStream is = (InputStream) this.getClass().getResourceAsStream( "/db.properties");//創建輸出流 try { load(is);//讀取流 is.close(); } catch (IOException e) { e.printStackTrace(); } } private static Env instance;//當前類實例 /** * 獲得當前實例 * @return */ public static Env getInstance() { if (instance == null) { makeInstance(); } return instance; } /** * 創建當前類實例 */ private static synchronized void makeInstance() { if (instance == null) { instance = new Env(); } } }

2.通過讀取配置文件的類獲取數據庫連接參數

 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獲取

1.在Tomcat安裝目錄的conf目錄下的context.xml文件的<Context/>標記中添加配置

<Resource name="jdbc/books" auth="Container" type="javax.sql.DataSource" maxActive="1000" maxIdel="30" maxWait="10000" username="sa" password="ok" driverClassName="com.microsoft.sqlserver.jdbc.SQLServerDriver" url="jdbc:sqlserver://localhost:1433;DatabaseName=books" />

2.編碼獲取數據庫連接

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; } }