Tomcat中配置数据源

一、Tomcat6.0中配置数据源
1.在Tomcat根目录/conf/Catalina/localhost目录下新建一个XML文件,文件名称跟工程名称一致.文件中的内容如下：
<?xml version='1.0' encoding='utf-8'?>
<Context docBase="E:\Eclipse3.4.2\workspace\mmis\WebContent" path="/mmis">
<Resource name="mmisds" type="javax.sql.DataSource"
factory="org.apache.commons.dbcp.BasicDataSourceFactory"
driverClassName="Oracle.jdbc.driver.OracleDriver"
url="jdbc:oracle:thin:@192.168.2.250:1521:hmisb"
username="mtms" password="mtms"
validationQuery="select 1 from dual"
maxIdle="100" maxActive="500" maxWait="1000" defaultAutoCommit="true"
removeAbandoned="ture" removeAbandonedTimeout="60" logAbandoned="true"/>
</Context>
2.在tomcat的conf/context.xml中的<Context>标签中添加一个<Resource/>,内容如下:
<Resource name="jdbc/oa" auth="Container" type="javax.sql.DataSource"
factory="org.apache.commons.dbcp.BasicDataSourceFactory"
maxActive="100" maxIdle="500" maxWait="10000"
username="oa" password="oa" driverClassName="oracle.jdbc.driver.OracleDriver"
url="jdbc:oracle:thin:@172.16.60.30:1521:HMIS" defaultAutoCommit="true"
removeAbandoned="ture" removeAbandonedTimeout="60" logAbandoned="true" />
然后在web.xml<web-app>中添加引用(tomcat5.5以上可以不用添加这一段)
<resource-ref>
<description>DB Connection</description>
<res-ref-name>jdbc/oa</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
2.1.获取连接对象
public class ConnectionPool{
public static Connection getConn()throws Exception{
//初始化上下文
Context initContext=getInitContext();
Context envContext=(Context)initContext.lookup("java:/comp/env");
DataSource dataSource=(DataSource)envContext.lookup("jdbc/oa");
//获取连接对象
return ds.getConnection();
}
}
docBase是指Web工程所在的位置,path是工程的名称, name是指JNDI的名称,type是数据源的类型,driverClassName是驱动名称,url是驱动的连接字符串
username是指数据库的用户名，password是指数据库的密码,defaultAutoCommit是否自动提交
二、Tomcat5.x中配置全局连接池
1.打Tomcat根目录/conf/server.xml文件，在<GlobalNamingResources>标签下添加
<GlobalNamingResources>
<Resource auth="Container" name="RLDMDataSource" scope="Shareable" type="javax.sql.DataSource" /> 
<ResourceParams name="RLDMDataSource">
<parameter>
<name>factory</name>
<value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
</parameter>
<parameter>
<name>driverClassName</name>
<value>oracle.jdbc.driver.OracleDriver</value>
</parameter>
<parameter>
<name>url</name>
<!--<value>jdbc:jtds:sqlserver://localhost:1433;DatabaseName=pubs</value> SQL数据库 -->
<value>jdbc:oracle:thin:@172.16.61.13:1521:服务名</value> <!-- Oracle数据库 -->
</parameter>
<parameter>
<name>username</name>
<value>clgc</value>
</parameter>
<parameter>
<name>password</name>
<value>clgc</value>
</parameter>
<parameter>
<name>validationQuery</name>
<value>select count(*) from dual</value>
</parameter>
<parameter>
<name>maxIdle</name>
<value>5</value>
</parameter>
<parameter>
<name>maxActive</name>
<value>10</value>
</parameter>
<parameter>
<name>maxWait</name>
<value>-1</value>
</parameter>
<parameter>
<name>removeAbandoned</name>
<value>true</value>
</parameter> 
<parameter>
<name>removeAbandonedTimeout</name>
<value>60</value>
</parameter>
<parameter>
<name>logAbandoned</name>
<value>true</value>
</parameter>
</ResourceParams> 
</GlobalNamingResources>
2.在Host标签下添加<Context>标签
<Host name="localhost" debug="0" appBase="webapps"
unpackWARs="true" autoDeploy="true"
xmlValidation="false" xmlNamespaceAware="false">
<Context path="/rldmpda" docBase="D:\Tomcat 5.0\webapps\rldmpda" debug="0" reloadable="true">
<ResourceLink name="jdbc/RldmDB" global="RLDMDataSource" type="javax.sql.DataSource" /> 
</Context>
</Host>
这里的<Context path="/rldmpda" docBase="D:\Tomcat 5.0\webapps\rldmpda" debug="0" reloadable="true">
path是指项目发布在tomcat webapps目录下的路径,我的项目目录为：../tomcat5.0/webapps/rldmpda
docBase是指项目的
在JSP里有两种实现的办法，一种是用JNDI(Java Naming Directory Interface)，这可能和应用服务器有关，如果是Resin，先在resin.conf里定义 
<resource-ref> 
<res-ref-name>jdbc/oracle</res-ref-name> 
<res-type>javax.sql.DataSource</res-type> 
<init-param driver-name="oracle.jdbc.driver.OracleDriver"/> 
<init-param url="jdbc:oracle:thin:@192.168.1.1:1521:oracle"/> 
<init-param user="system"/> 
<init-param password="manager"/> 
<init-param max-connections="20"/> 
<init-param max-idle-time="30"/> 
</resource-ref> 

如果为Tomcat，在Server.xml里面定义，有关的资料可以查文档，然后在jsp里这样用 
try{ 
javax.naming.Context env = (Context)new InitialContext().lookup("java:comp/env"); 
javax.sql.DataSource pool=(javax.sql.DataSource) env.lookup("jdbc/oracle"); 
}catch(Exception e){System.err.println("Exception error:"+e.getMessage());} 

try { 
Connection conn = pool.getConnection(); 
}catch(Exception e){System.out.println("Exception error:"+e.getMessage());} 
通过这段代码，你就获得从连接池里获得了一个连接conn。如果想用普通的连接池，那只能用JavaBean了，先写一个ConnectionPool的java的类，然后直接从连接池中获得连接，下面是我一个连接池的JavaBean 
ConnectionPool.java如下： 

import java.io.PrintStream; 
import java.sql.Connection; 
import java.util.Vector; 

// Referenced classes of package com.ilovejsp.sql: 
// DataSource, PooledConnection 

public class ConnectionPool 
{ 
private Vector pool; 
private int size; 
DataSource db; 

public ConnectionPool() 
{ 
pool = null; 
size = 0; 
db = new DataSource(); 
} 

public void setSize(int value) 
{ 
if(value > 1) 
size = value; 
} 

public int getSize() 
{ 
return size; 
} 

public synchronized void initPool() 
throws Exception 
{ 
try 
{ 
for(int x = 0; x < size; x++) 
{ 
Connection conn = db.getConnection(); 
if(conn != null) 
{ 
PooledConnection pcon = new PooledConnection(conn); 
addConnection(pcon); 
} 
} 

} 
catch(Exception e) 
{ 
System.err.println(e.getMessage()); 
} 
} 

private void addConnection(PooledConnection pcon) 
{ 
if(pool == null) 
pool = new Vector(size); 
pool.addElement(pcon); 
} 

public synchronized void releaseConnection(Connection conn) 
{ 
int x = 0; 
do 
{ 
if(x >= pool.size()) 
break; 
PooledConnection pcon = (PooledConnection)pool.elementAt(x); 
if(pcon.getConnection() == conn) 
{ 
System.err.println("Release Connection".concat(String.valueOf(String.valueOf(x)))); 
pcon.setInUse(false); 
break; 
} 
x++; 
} 
while(true); 
} 

public synchronized Connection getConnection() 
throws Exception 
{ 
PooledConnection pcon = null; 
for(int x = 0; x < pool.size(); x++) 
{ 
pcon = (PooledConnection)pool.elementAt(x); 
if(!pcon.inUse()) 
{ 
pcon.setInUse(true); 
return pcon.getConnection(); 
} 
} 

try 
{ 
Connection conn = db.getConnection(); 
pcon = new PooledConnection(conn); 
pcon.setInUse(true); 
pool.addElement(pcon); 
} 
catch(Exception e) 
{ 
System.err.println("Exception error:".concat(String.valueOf(String.valueOf(e.getMessage())))); 
} 
return pcon.getConnection(); 
} 

public synchronized void emptyPool() 
{ 
for(int x = 0; x < pool.size(); x++) 
{ 
System.err.println("Closing Jdbc Connection".concat(String.valueOf(String.valueOf(x)))); 
PooledConnection pcon = (PooledConnection)pool.elementAt(x); 
if(!pcon.inUse()) 
{ 
pcon.close(); 
continue; 
} 
try 
{ 
Thread.sleep(3000L); 
pcon.close(); 
} 
catch(Exception e) 
{ 
System.out.println("Exception :".concat(String.valueOf(String.valueOf(e.getMessage())))); 
} 
} 

db.close(); 
} 
} 
testpool.jsp内容如下： 
<%@ page language="java" contentType="text/html;charset=gb2312"%> 
<%@ page import="java.sql.*"%> 

<HTML> 
<HEAD> 
<TITLE>系统数据信息</TITLE> 
</HEAD> 
<BODY> 
<%ConnectionPool db=new ConnectionPool(); 
Connection conn=db.getConnection(); 
Statement stmt=conn.createStatement(); 
String sql1="select * from pg_database "; 

ResultSet rs=stmt.executeQuery(sql1); 
%> 
<TABLE><TR><TD>系统数据库信息</TD></TR> 
<TR><TD> 
<%while(rs.next()) { 
%> 
<%=rs.getString(1)%> 
<%} 
rs.close();%> 
</TR></TD> 
<TABLE><TR><TD>系统字段信息</TD></TR> 
<TR><TD> 
<%String sql2="select * from pg_type"; 
rs=stmt.executeQuery(sql2); 
while(rs.next()) { 
%> 
(<%=rs.getString(1)%>) 
<%} 
rs.close(); 
db.close();%> 
</TR></TD> 
</BODY> 
</HTML>