java中配置数据库连接池总结 
在tomcat下配置mysql数据源

1.1 配置server.xml 

在tomcat5.0-->conf-->server.xml的<host></host>标记中加入以下代码:

<Context path="/hibernate_test" reloadable="true" docBase="E:\testeclipse\workspace\myhibernate_test\hibernate_test" workDir="E:\testeclipse\workspace\myhibernate_test\work">
<Resource name="jdbc/list" auth="Container" type="javax.sql.DataSource"/>
  <ResourceParams name="jdbc/list">
  
    <parameter>
    <name>factory</name>
    <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
    </parameter>
    
    <parameter>
    <name>driverClassName</name>
    <value>org.gjt.mm.mysql.Driver</value> 
    </parameter>
    
    <parameter>
    <name>url</name>
    <value>jdbc:mysql://10.71.0.187:8000/test?characterEncoding=gbk</value> 
    </parameter>
    
    <parameter>
    <name>username</name>
    <value>omnipay</value>
    </parameter>
    
    <parameter>
    <name>password</name>
    <value>omnipay</value>
    </parameter>
    
    <parameter>
    <name>maxActive</name>
    <value>20</value>
    </parameter>
    
    <parameter>
    <name>maxIdle</name>
    <value>20</value>
    </parameter>
    
    <parameter>
    <name>maxWait</name>
    <value>-1</value>
    </parameter>
  
</ResourceParams>
</Context>


或者在Tomcat 5.0\conf\Catalina\localhost目录下添加一个和web项目同名的一个xml文件,内容如下:

<Context path="/list_test" reloadable="true" docBase="list_test">
  <Resource name="jdbc/list" auth="Container" type="javax.sql.DataSource"/>
  <ResourceParams name="jdbc/list">
      <parameter>
  <name>factory</name>
      <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
    </parameter>
  <parameter>
    <name>initialSize</name>
    <value>5</value>
    </parameter>
    <parameter>
    <name>maxActive</name>
    <value>20</value>
    </parameter>
    <parameter>
    <name>maxIdle</name>
  <value>10</value>
    </parameter>
  <parameter>
    <name>minIdle</name>
  <value>5</value>
    </parameter>
  <parameter>
    <name>timeBetweenEvictionRunsMillis</name>
  <value>300000</value>
    </parameter>
    <parameter>
    <name>maxWait</name>
      <value>10000</value>
    </parameter>
  <parameter>
          <name>removeAbandoned</name>
          <value>true</value>
        </parameter>
  <parameter>
          <name>removeAbandonedTimeout</name>
          <value>60</value>
        </parameter>
  <parameter>
          <name>logAbandoned</name>
          <value>false</value>
        </parameter>
      <parameter>
      <name>username</name>
      <value>omnipay</value>
      </parameter>
      <parameter>
      <name>password</name>
      <value>omnipay</value>
      </parameter>
    <parameter>
      <name>driverClassName</name>
      <value>com.mysql.jdbc.Driver</value>
    </parameter>
    <parameter>
    <name>url</name>
  <value>jdbc:mysql://10.71.0.187:8000/test?characterEncoding=gbk</value>
    </parameter>
  </ResourceParams>
</Context>


或者在struts_config.xml中添加以下代码:

<data-sources >
  <data-source key="org.apache.struts.action.DATA_SOURCE" type="org.apache.commons.dbcp.BasicDataSourceFactory">
    <set-property property="password" value="omnipay" />
    <set-property property="minCount" value="" />
    <set-property property="maxCount" value="" />
    <set-property property="user" value="omnipay" />
    <set-property property="driverClass" value="com.mysql.jdbc.Driver" />
    <set-property property="description" value="jdbc/jndi" />
    <set-property property="url" value="http://localhost:8000/test" />
    <set-property property="readOnly" value="false" />
    <set-property property="autoCommit" value="false" />
    <set-property property="loginTimeout" value="" />
  </data-source>
</data-sources>

  1.2 配置web.xml

在web.xml中添加以下代码:

<web-app>
<description>MySQL Test App</description>
<resource-ref>
    <description>DB Connection</description>
    <res-ref-name>jdbc/TestDB</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
</resource-ref>
</web-app>




1.3 访问数据库的java代码
DbConnection.java

import java.sql.Connection;
import java.sql.SQLException;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;
/**
* @date 2006-1-3
* @author user 数据库连接的通用类
*/
public final class DbConnection {
  private static DbConnection dbConn;
  private DbConnection() throws SQLException {
  }
  //获得数据库连接
  public synchronized Connection getConnection() throws SQLException {
    Connection con = null;
    try {
        InitialContext ctx = new InitialContext();
        Context ct = (Context) ctx.lookup("java:comp/env");
        DataSource ds = (DataSource) ct.lookup("jdbc/omnipay");
        con = ds.getConnection();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return con;
  }
  public static synchronized DbConnection getInstance() throws SQLException {
    if (dbConn == null) {
        dbConn = new DbConnection();
    }
    return dbConn;
  }
}


写一个数据库访问类
  1.4 写一个action类及jsp页面测试一下就OK了