Tomcat中配置MySQL資料庫連接配接池
Web開發中與資料庫的連接配接是必不可少的,而資料庫連接配接池技術很好的優化了動态頁與資料庫的連接配接,相比單個連接配接資料庫連接配接池節省了很大的資源。用一個通俗的比喻:如果一個人洗澡需花一桶水,那一百個人就要花一百桶水,太浪費了.如果都在池子裡洗,洗多少個人都不怕了。
1.将MySQL的JDBC驅動複制到Tomcat安裝目錄裡的lib檔案夾下。驅動可以從MySQL官網上下載下傳,為jar包。
2.将Tomcat的配置檔案Context.xml做如下修改:
<Context path="/DBTest" docBase="DBTest"
debug="5" reloadable="true" crossContext="true">
<!-- maxActive: Maximum number of dB connections in pool. Make sure you
configure your mysqld max_connections large enough to handle
all of your db connections. Set to -1 for no limit.
-->
<!-- maxIdle: Maximum number of idle dB connections to retain in pool.
Set to -1 for no limit. See also the DBCP documentation on this
and the minEvictableIdleTimeMillis configuration parameter.
-->
<!-- maxWait: Maximum time to wait for a dB connection to become available
in ms, in this example 10 seconds. An Exception is thrown if
this timeout is exceeded. Set to -1 to wait indefinitely.
-->
<!-- username and password: MySQL dB username and password for dB connections -->
<!-- driverClassName: Class name for the old mm.mysql JDBC driver is
org.gjt.mm.mysql.Driver - we recommend using Connector/J though.
Class name for the official MySQL Connector/J driver is com.mysql.jdbc.Driver.
-->
<!-- url: The JDBC connection url for connecting to your MySQL dB.
The autoReconnect=true argument to the url makes sure that the
mm.mysql JDBC Driver will automatically reconnect if mysqld closed the
connection. mysqld by default closes idle connections after 8 hours.
-->
<Resource name="jdbc/TestDB" auth="Container" type="javax.sql.DataSource"
maxActive="100" maxIdle="30" maxWait="10000"
username="javauser" password="javadude" driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/javatest?autoReconnect=true"/>
</Context>
注意代碼中紅色部分: DBTest 改為自己的項目路徑; TestDB改為自己的資料源名,但是後面使用時候要與這裡的配置保持一緻; javauser和 javauser改為自己MySQL的使用者名密碼;url的格式依次為 jdbc:mysql://{你的資料庫服務所在的IP,如果為本機就為localhost}:{你的資料庫服務端口号}/{MySQL中要使用的資料庫名稱}?autoReconnect=true 。
3.修改項目WEB-INF/web.xml 配置檔案(若無,請建立),在“</web-app>”之上添加如下代碼:
<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>
上步中若修改了資料源名此步中紅色部分請保持與上步中的一緻。
4.代碼示例:
Context initContext = new InitialContext();
Context envContext = (Context)initContext.lookup("java:/comp/env");
DataSource ds = (DataSource)envContext.lookup("jdbc/TestDB");
Connection conn = ds.getConnection();
Statement st = null;
ResultSet rs = null;
st = conn.createStatement();
rs = st.executeQuery(yoursql);
注意紅色部分與上兩步中的一緻;yoursql處寫你的sql代碼。
通過1-3步就在Tomcat中配置好了MySQL的資料庫連接配接池。如果有什麼問題可以在本文下方留言。
本文轉載自:http://www.littlear.com/post/2010/06/1051/