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;
public final class MysqlConn {
// 懒汉式单例(使用时才new)
private static 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
public static 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;
public final class OracleConn {
// 懒汉式单例(使用时才new)
private static 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
public static 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: