tomcat连接池问题

03-09-23 ctrlv

用tomcat内置的连接池配置(maxActive=20),在jsp页面得到连接。头几次进页面没问题,之后奇慢无比,进不去页面,什么原因?请高手指点,不胜感激。(注:jsp页面内用session存连接,如果session==null重新建连接)。

ioly
2003-09-23 11:19

把连接存在session里面不太好吧, 迟早吃光连接池.

连接应该是即时获取即时释放.

以前我也试过跨页面io使用Connection, 结果创造了tomcat一天重启5次的纪录.

charlie
2003-09-24 11:07

通常做法是建立一个SERVERLET,负责所有的数据库访问.然后在每个会话过程中保存它的应用,通过它来实现数据库的访问和数据结果的封装,然后返回。

anonymous
2003-09-24 15:27

通常做法是写一个singleton类,把查找到的ds,保存在里面,通过它来实现数据库连接与释放,然后返回。

anonymous
2003-09-24 15:31

like this:

// 在此输入java代码
/*
 * 数据源管理器,可以管理多个数据源
 * 提高 JNDI 查找的速度
 */

package comm.ds;

import java.util.HashMap;
import java.util.Map;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;

public class DataSourceManager {

	private static DataSourceManager instance;

	private Map dataSources;
	private Context context;

	// This is private, and can't be instantiated directly
	private DataSourceManager() throws NamingException {
		dataSources = new HashMap();

		// Get the context for caching purposes
		context = new InitialContext();

		/**
		 * In non-J2EE applications, you might need to load up
		 *   a properties file and get this context manually. I've
		 *   kept this simple for demonstration purposes.
		 */
	}

	public static DataSourceManager getInstance() throws NamingException {
		// Not completely thread-safe, but good enough 
		// (see note in article)
		if (instance == null) {
			instance = new DataSourceManager();
		}
		return instance;
	}

	public DataSource lookup(String jndiName)
		throws NamingException {

		// See if we already have this interface cached
		DataSource ds = (DataSource) dataSources.get(jndiName);

		// If not, look up with the supplied JNDI name
		if (ds == null) {
			ds =(DataSource) context.lookup(jndiName);
			
			// If this is a new ref, save for caching purposes
			dataSources.put(jndiName, ds);
		}
		return ds;
	}
}

<p>

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