几种创建数据库链接的方式

1.采用jdbc方式
public static Connection getConnection() throws SQLException
{
Connection con = null;
try {
long beginTime = System.currentTimeMillis();
Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
con = DriverManager.getConnection (url,username,password);
long endTime = System.currentTimeMillis();

} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return con;
}
2.应用weblogic的JNDI方式
public Connection getConnection() throws Exception
  {
  Context initctx=null;
  Context ctx=null;
  DataSource ds=null;
  Connection conn=null;
  String aa="";
  try {
  Hashtable   env   =   new   Hashtable();  
              env.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");  
              env.put(Context.PROVIDER_URL,   "t3://localhost:7001");  
              env.put(Context.SECURITY_PRINCIPAL,"weblogic");  
              env.put(Context.SECURITY_CREDENTIALS,   "weblogic");  
              ctx   =   new   InitialContext(env);  
              ds=(DataSource)ctx.lookup("jdbc/lmss");  
      conn = ds.getConnection();
 
  log.info("=====dss=======" + ds);
  if(ds==null) throw new Exception("no database");
  } catch (Exception e) {
  e.printStackTrace();
  log.info("=======getConnection(aa) begin=====");
  conn = getConnection(aa);
  }
return conn;
  }
3.应用websphere的JNDI方式
Hashtable ht = new Hashtable();
    ht.put(Context.INITIAL_CONTEXT_FACTORY,
              "com.ibm.websphere.naming.WsnInitialContextFactory");
        ht.put(Context.PROVIDER_URL, "iiop://127.0.0.1:2810");
        Context ctx = new InitialContext(ht);
ds=(DataSource)ctx.lookup("jdbc/stock");
if(ds==null) throw new NamingException("no database");
con=ds.getConnection();

4.可以通过spring的配置文件获得datasource
ApplicationContext ctx=new FileSystemXmlApplicationContext("classpath:applicationContext-common.xml");
myDataSource = (DataSource) ctx.getBean("dataSource");
con = myDataSource.getConnection();