（原创，残梦追月转载请注明！）
原来在我的csdn上，转帖过来。
使用jdbc连接数据库所有功能都没问题，发布到tomcat中也没问题，可是如果使用tomcat的数据源，来连接数据库，开始很正常，但是刷新几次就会出现这个异常……
2008-04-26 22:35:40,812 WARN [org.hibernate.util.JDBCExceptionReporter] - SQL Error: 0, SQLState: null
2008-04-26 22:35:40,812 ERROR [org.hibernate.util.JDBCExceptionReporter] - Cannot get a connection, pool error Timeout waiting for idle object
2008-04-26 22:35:40,812 WARN [org.hibernate.util.JDBCExceptionReporter] - SQL Error: 0, SQLState: null
2008-04-26 22:35:40,812 ERROR [org.hibernate.util.JDBCExceptionReporter] - Cannot get a connection, pool error Timeout waiting for idle object
2008-04-26 22:35:40,812 ERROR [com.dao.MessageDAO] - find all failed
org.springframework.jdbc.UncategorizedSQLException: Hibernate operation: Cannot open connection; uncategorized SQLException for SQL [???]; SQL state [null]; error code [0]; Cannot get a connection, pool error Timeout waiting for idle object; nested exception is org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot get a connection, pool error Timeout waiting for idle object
Caused by:
org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot get a connection, pool error Timeout waiting for idle object
at org.apache.tomcat.dbcp.dbcp.PoolingDataSource.getConnection(PoolingDataSource.ｊａｖａ:104)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.ｊａｖａ:880)
at org.springframework.orm.hibernate3.LocalDataSourceConnectionProvider.getConnection(LocalDataSourceConnectionProvider.ｊａｖａ:81)
……………………
开始弄了半天也不知道怎么回事，后来发现是我自己写的分页代码有问题……原来的代码如下：
1 /**
2 * 自定义的，用属性模糊查询
3 *
4 * */
5 public List find(String propertyName, Object value) {
6
7 log.debug("finding Message instance with property: " + propertyName
8
9 + ", value: " + value);
10
11 try {
12
13 String queryString = "from Message as model where model."
14
15 + propertyName + " like "+value+" order by model.time desc";
16
17 return getHibernateTemplate().find(queryString);
18
19 } catch (RuntimeException re) {
20
21 log.error("find by property name failed", re);
22
23 throw re;
24
25 }
26
27 }
28
29
30 /**
31 *
32 * 自定义的方法，获取指定页的数据
33 *
34 * */
35 public List gotoPage(int page,int pageSize){
36
37
38
39 int totItem = this.findAll().size();//记录总条数
40
41 int pageNum = totItem / pageSize +1;//总页数
42
43 int begin = 0;//当前起始记录数
44
45
46 begin=page*pageSize-pageSize+1; //计算当前起始位置
47
48
49 Session s =this.getSession();
50
51 String hql = "from Message message order by message.time desc";
52
53 Query q =s.createQuery(hql);
54
55 q.setFirstResult(begin);
56
57 q.setMaxResults(pageSize);
58
59 return q.list();
60
61 }
在这句中：
Session s =this.getSession();
String hql = "from Message message order by message.time desc";
Query q =s.createQuery(hql);
查询数据时，Spring并不能够自动管理连接，也就是说，在使用中这几句代码重视不段的获取数据库的连接，每调用一次就申请一个连接……直到 tomcat连接池中的连接耗尽……所以就再也申请不到连接了……出现了这个异常，解决办法是使用事务来管理这段代码，让Spring自动管理这段代码中申请的连接。我使用了Spring AOP自动事务代理……配置文件如下……
1 <bean id="JndiDataSource"
2 class="org.springframework.jndi.JndiObjectFactoryBean">
3 <property name="jndiName">
4 <value>java:comp/env/SqlServer</value>
5 </property>
6 <property name="resourceRef">
7 <value>true</value>
8 </property>
9 </bean>
10
11 <!-- hibernate的会话工厂 -->
12 <bean id="sessionFactory"
13 class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
14 <property name="dataSource">
15 <ref bean="JndiDataSource"></ref>
16 </property>
17 <property name="hibernateProperties">
18 <props>
19 <prop key="hibernate.dialect">
20 org.hibernate.dialect.SQLServerDialect
21 </prop>
22 <!-- 显示SQL，为了方便测试 -->
23 <prop key="hibernate.show_sql">true</prop>
24 </props>
25 </property>
26 <property name="mappingResources">
27 <list><!-- 映射文件 -->
28 <value>./Message.hbm.xml</value>
29 <value>./Setting.hbm.xml</value>
30 <value>./Admin.hbm.xml</value>
31 </list>
32 </property>
33 </bean>
34
35 <!-- 事务管理器 -->
36 <bean id="transactionManger"
37 class="org.springframework.orm.hibernate3.HibernateTransactionManager">
38 <property name="sessionFactory">
39 <ref bean="sessionFactory" />
40 </property>
41 </bean>
42
43 <!-- 配置事务拦截器-->
44
45 <bean id="transactionInterceptor"
46 class="org.springframework.transaction.interceptor.TransactionInterceptor">
47 <property name="transactionManager">
48 <ref bean="transactionManger" />
49 </property>
50 <!-- 下面定义事务传播属性-->
51 <property name="transactionAttributes">
52 <props>
53 <prop key="find*">PROPAGATION_REQUIRED</prop>
54 <prop key="delete*">PROPAGATION_REQUIRED</prop>
55 <prop key="save*">PROPAGATION_REQUIRED</prop>
56 <prop key="merge*">PROPAGATION_REQUIRED</prop>
57 <prop key="attach*">PROPAGATION_REQUIRED</prop>
58 <prop key="gotoPage">PROPAGATION_REQUIRED</prop>
59 </props>
60 </property>
61 </bean>
62
63 <!-- 自动代理 -->
64 <bean id="autoBeanNameProxyCreator"
65 class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
66 <property name="beanNames">
67 <list>
68 <value>*DAO</value>
69 <value>gotoPage</value>
70 <value>find</value>
71 </list>
72 </property>
73 <property name="interceptorNames">
74 <list>
75 <idref local="transactionInterceptor" />
76 </list>
77 </property>
78 <!-- 这里的配置是必须的，否则无法完成代理的类型转化 这是使用CGLIB来生成代理 -->
79 <property name="proxyTargetClass" value="true"/>
80 </bean>
81
82 <bean id="MessageDAO" class="com.dao.MessageDAO">
83 <property name="sessionFactory">
84 <ref bean="sessionFactory"></ref>
85 </property>
86 </bean>
87
88 <bean id="SettingDAO" class="com.dao.SettingDAO">
89 <property name="sessionFactory">
90 <ref bean="sessionFactory"></ref>
91 </property>
92 </bean>
93
94 <bean id="AdminDAO" class="com.dao.AdminDAO">
95 <property name="sessionFactory">
96 <ref bean="sessionFactory"></ref>
97 </property>
98 </bean>
OK，问题成功解决！速度好像还快些！
By：残梦追月
posted on 2008-07-15 17:57
残梦追月 阅读(10466)
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