JavaWeb：Tomcat下配置数据源连接数据库

本人亲测，绝对通过：

我是用Tomcat7.0，下面是详细步骤：

1.Tomcat7.0的lib目录下加进去驱动“mysql-connector-java-5.1.17-bin.jar”,这个相信都会的。

2.在Tomcat 7.0\conf下找到context.xml文件，没有的话新建一个，将改文件的内容做如下修改：

context.xml:（红色部分是要加入的代码）

<?xml version='1.0' encoding='utf-8'?>
<!--
  Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->
<!-- The contents of this file will be loaded for each web application -->
<Context>

    <!-- Default set of monitored resources -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
    <!--
    <Manager pathname="" />
    -->

    <!-- Uncomment this to enable Comet connection tacking (provides events
         on session expiration as well as webapp lifecycle) -->
    <!--
    <Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
    -->

<Resource 
        name="newname"
        auth="Container" 
        type="javax.sql.DataSource"
        maxActive="100" maxIdle="30" maxWait="10000"
        username="root" password="你设的密码" 
        driverClassName="com.mysql.jdbc.Driver"
        url="jdbc:mysql://localhost:3306/数据库名?autoReconnect=true"
    />

</Context>

下面是测试代码：

InitialContext ctx = new InitialContext();
        DataSource ds = (DataSource) ctx.lookup("java:comp/env/newname");
        conn = ds.getConnection();
        Stmt =conn.createStatement();
        sqlRst=Stmt.executeQuery("select a,b from 数据库中的表名");

本人亲测，完全OK !