1.将数据库的jar包放到工程的lib下

2.在tomcat的/conf/context.xml文件中添加(一些参数需要修改)

    <Resource name="jdbc/oracle" type="javax.sql.DataSource"

    driverClassName="oracle.jdbc.OracleDriver" url="jdbc:oracle:thin:@127.0.0.1:1521:orcl"

    username="dtm" password="dtm" maxActive="50" maxIdle="20" maxWait="10000" />

3.测试数据库连接代码

    public class DBConn {

    private static Connection conn;

    public static Connection getConn(String name){

    try {

    Context initContext = new InitialContext();

    DataSource ds = (DataSource) initContext.lookup("java:comp/env/jdbc/oracle");

    conn = ds.getConnection();

    } catch (NamingException e) {

    e.printStackTrace();

    } catch (SQLException e) {

    e.printStackTrace();

    }

    return conn;

    }

    }

PS：红色字体部分数据库名称要相同一致