Tomcat配置多数据源

测试的tomcat为apache-tomcat-6.0.18 ，数据库为mysql和oracle。

配置步骤如下：

1、把数据库的JDBC驱动放入D:\apache-tomcat-6.0.18\lib目录下

2、在D:\apache-tomcat-6.0.18\conf\web.xml文件中，将下面代码加入到web.xml中：

<resource-ref><description>DB Connection</description><res-ref-name>jdbc/mysql</res-ref-name><res-type>javax.sql.DataSource</res-type><res-auth>Container</res-auth></resource-ref><resource-ref><description>DB Connection</description><res-ref-name>jdbc/oracle</res-ref-name><res-type>javax.sql.DataSource</res-type><res-auth>Container</res-auth></resource-ref>

3、在D:\apache-tomcat-6.0.18\conf\server.xml文件中,在Host节点下添加Context子节点，配置如下

<Context path="/ljqtest" docBase="ljqtest" debug="5" reloadable="true" crossContext="true"><Resource name="jdbc/mysql" type="javax.sql.DataSource" username="root" password="mysql" driverClassName="org.gjt.mm.mysql.Driver" url="jdbc:mysql://localhost:3306/shop" maxIdle="2" maxWait="50" maxActive="4"><parameter><name>removeAbandoned</name><value>true</value></parameter></Resource><Resource name="jdbc/oracle" type="javax.sql.DataSource" username="test" password="test" driverClassName="oracle.jdbc.driver.OracleDriver" url="jdbc:oracle:thin:@localhost:1521:ORCL" maxIdle="2" maxWait="50" maxActive="4"><parameter><name>removeAbandoned</name><value>true</value></parameter></Resource></Context></Host>

或者

<Context path="/uimcardprj" docBase="uimcardprj" debug="5" reloadable="true" crossContext="true"><Resource name="jdbc/ycxkDB" type="javax.sql.DataSource" username="ycxk" password="xmzh" driverClassName="oracle.jdbc.driver.OracleDriver" url="jdbc:oracle:thin:@(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = 134.128.48.250)(PORT = 1521))(CONNECT_DATA =(SERVER = DEDICATED)(SERVICE_NAME = orcl)))" maxIdle="2" maxWait="50" maxActive="4"></Resource></Context></Host>

注意：path为D:\apache-tomcat-6.0.18\webapps目录下的工程名称 4、把web工程项目部署在D:\apache-tomcat-6.0.18\webapps目录下

MysqlConn类：获取Mysql数据源

package com.ljq.test;
import java.sql.Connection; import java.sql.SQLException;
import javax.naming.Context; import javax.naming.InitialContext; import javax.sql.DataSource;
publicfinalclass MysqlConn {     // 懒汉式单例(使用时才new)privatestatic MysqlConn instance =null;
    MysqlConn() {     }
    // 延迟初始化(用到的时候才加载)(推荐)     // public static synchronized JdbcConn     // getInstance(){}->这样不好，因为每调用一次就同步，效率非常低publicstatic MysqlConn getInstance() {         if (instance ==null) {             synchronized (MysqlConn.class) {// 可能会产生并发的问题，我们对他进行同步if (instance ==null) {                     instance =new MysqlConn();                 }             }         }         return instance;     }          private DataSource getDataSource() {         DataSource ds =null;         try {             Context ctx =new InitialContext();             ds = (DataSource) ctx.lookup("java:comp/env/jdbc/mysql");         } catch (Exception e) {             System.out.println("数据源获取失败");             e.printStackTrace();         }         return ds;     }
    public Connection getConn() {         Connection conn =null;         try {             conn = getDataSource().getConnection();         } catch (SQLException e) {             System.out.println("数据库连接失败");             e.printStackTrace();         }         return conn;     }
}

OraclelConn类：获取Oracle数据源

package com.ljq.test;
import java.sql.Connection; import java.sql.SQLException;
import javax.naming.Context; import javax.naming.InitialContext; import javax.sql.DataSource;
publicfinalclass OracleConn {     // 懒汉式单例(使用时才new)privatestatic OracleConn instance =null;
    OracleConn() {     }
    // 延迟初始化(用到的时候才加载)(推荐)     // public static synchronized JdbcConn     // getInstance(){}->这样不好，因为每调用一次就同步，效率非常低publicstatic OracleConn getInstance() {         if (instance ==null) {             synchronized (OracleConn.class) {// 可能会产生并发的问题，我们对他进行同步if (instance ==null) {                     instance =new OracleConn();                 }             }         }         return instance;     }          private DataSource getDataSource() {         DataSource ds =null;         try {             Context ctx =new InitialContext();             ds = (DataSource) ctx.lookup("java:comp/env/jdbc/mysql");         } catch (Exception e) {             System.out.println("数据源获取失败");             e.printStackTrace();         }         return ds;     }
    public Connection getConn() {         Connection conn =null;         try {             conn = getDataSource().getConnection();         } catch (SQLException e) {             System.out.println("数据库连接失败");             e.printStackTrace();         }         return conn;     }
}

页面index.jsp:打印数据库连接对象

<body> mysql连接对象为：<%Connection conn=MysqlConn.getInstance().getConn();%><%=conn %><%conn.close();%><br/> oracle连接对象为：<%Connection conn2=MysqlConn.getInstance().getConn();%><%=conn2 %><%conn2.close();%><br/></body>

5、启动tomcat，在浏览器中输入：http://localhost:8083/ljqtest/，输出如下：